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The thermal properties of beeswaxes: Unexpected findings
Abstract
Standard melting point analyses only partially describe the thermal properties of eusocial beeswaxes. Differential scanning calorimetry (DSC) revealed that thermal phase changes in wax are initiated at substantially lower temperatures than visually observed melting points. Instead of a sharp, single endothermic peak at the published melting point of 64 degrees C, DSC analysis of Apis mellifera Linnaeus wax yielded a broad melting curve that showed the initiation of melting at approximately 40 degrees C. Although Apis beeswax retained a solid appearance at these temperatures, heat absorption and initiation of melting could affect the structural characteristics of the wax. Additionally, a more complete characterization of the thermal properties indicated that the onset of melting, melting range and heat of fusion of beeswaxes varied significantly among tribes of social bees (Bombini, Meliponini, Apini). Compared with other waxes examined, the relatively malleable wax of bumblebees (Bombini) had the lowest onset of melting and lowest heat of fusion but an intermediate melting temperature range. Stingless bee (Meliponini) wax was intermediate between bumblebee and honeybee wax (Apini) in heat of fusion, but had the highest onset of melting and the narrowest melting temperature range. The broad melting temperature range and high heat of fusion in the Apini may be associated with the use of wax comb as a free-hanging structural material, while the Bombini and Meliponini support their wax structures with exogenous materials.
... Winterisation (recrystallisation from absolute alcohol at low temperatures [49]) resulted in a refined pine wax (RPW) with an enhanced content of aliphatic molecules, while resin acids and phytosterols were significantly reduced. Beeswax (BW) was also included in this study as a reference material [2,56]. Its chemical composition is known from the literature and differed considerably from both types of pine bark wax. ...
... Both waxes were stable up to about 200 • C, demonstrating that they could withstand downstream processing conditions. BW started to degrade at significantly higher temperatures (beyond 250 • C), in line with what has been reported earlier in the literature [56]. The increased thermal stability of the BW can be explained by its chemical composition, which contains a higher proportion of long-chain aliphatic (i.e., less volatile) components than either of the pine waxes [12,57]. ...
... Fatty alcohols which tend to melt at a lower temperature than carboxylic acids with the same chain length [61] or a small fraction of shorter chain molecules are possible candidates, but further research is required to confirm this working hypothesis. BW showed a more complex phase behaviour with even more pronounced melting and crystallisation peaks that were clearly composed of several overlapping transition processes, in line with earlier findings reported by other authors [56]. ...
Applying coatings of paraffins and other synthetic waxes is a common approach to impart hydrophobic properties to fibres and thus control their surface characteristics. Replacing these fossil-based products with alternatives derived from renewable resources can contribute to humankind’s transition to a sustainable bioeconomy. This study presents the coating of hemp fibres with waxes extracted from pine bark as an exemplar application. Two bio-based emulsifiers were used to prepare wax emulsions suitable for a dry blending process. The coatings on the fibres were characterised, quantified, and visualised using a combination of spectroscopic and microscopic techniques. Confocal fluorescence microscopy was an excellent tool to investigate the spatial distribution of the pine bark waxes on the fibre surfaces. While successful deposition was demonstrated for all tested formulations, coating homogeneity varied for different emulsifiers. Compounding the hemp fibres with a bio-based polyester resulted in the substantial improvement of the mechanical behaviour. However, the presence of a wax coating on the fibres did not lead to a significant change in mechanical properties compared to the controls with uncoated fibres. Optimising the composite chemistry or adjusting the processing conditions might improve the compatibility of the hemp fibres with the matrix material, resulting in enhanced mechanical performance.
... Then the thermograms were divided by the sample weight and the heat flows (in mW• • C) were calculated by integration. The fusion heat flow (I f ) corresponds to the area of the fusion curve between 35 • C and 70 • C whereas the solidification heat flow (I s ) corresponds to the area of the solidification curve between 30 • C and 65 • C. It was found easier to consider a fixed integration domain that is larger than what is usually used for standard latent heat measurements [24]. This option enabled to include, for all samples, the full range of thermal events while keeping the same integration bound thus facilitating the data process. ...
... As discussed in the literature, the thermal properties of beeswax depend on the bee species who produced it. However, the production of different colonies of the same species have comparable latent heats [24,32]. Our study deals with beeswax from European domestic honeybee (Apis melifera) meaning that the BW beeswax and the honeycomb fragment are expected to have a similar DSC response. ...
... Our study deals with beeswax from European domestic honeybee (Apis melifera) meaning that the BW beeswax and the honeycomb fragment are expected to have a similar DSC response. This point was checked (Appendix D) and the values found for the fusion enthalpy (178 J/g, estimated between 39 • C and 67 • C) are consistent with published data [24]. In addition, it was shown (Appendix D and E) that the heating treatment has no significant impact on BW beeswax thermograms and ATR-FTIR spectra. ...
Wet collections sealants are historical materials that are essential for a sustainable preservation of specimens in fluid. Yet little is known about their composition, apart what can be found in technical records. Few scientific studies are dedicated to the identification of these materials that often correspond to complex mixtures. This work aims at facilitating the characterization of beeswax-rosin mixtures used for sealing wet collections. It explores the possibilities to quantify the proportions of beeswax-rosin mixtures by Differential Scanning Calorimetry (DSC) and Attenuated Total Reflectance Fourier Transformed mid-Infrared Spectroscopy (ATR-FTIR), two easy-to-run methodologies that require small samples. First these techniques were tested on model beeswax-rosin mixtures and appeared complementary. Then they were implemented on historical sealants and cross-checked with Pyrolysis Gaz Chromatography Mass Spectroscopy (Py-GC/MS) measurements, giving promising results. The impact, on the results, of ageing or of possible addition of third-party fatty materials such as animal fat or vegetal oil is also discussed.
... To determine the melting behavior of the waxes, the temperature program was set as follows: heat from 25 to 100°C at 20°C/min, isothermal at 100°C for 20 min, cool to −30°C at 5°C/min, isothermal at −30°C for 20 min, and heat from -30 to 100°C at 5°C/ min. The onset temperature (°C), highest peak (melting point), and end of melting (Buchwald et al., 2008) were determined from the last heating scan. The melting range was determined from the difference between the end and beginning of the melting process (Buchwald et al., 2008). ...
... The onset temperature (°C), highest peak (melting point), and end of melting (Buchwald et al., 2008) were determined from the last heating scan. The melting range was determined from the difference between the end and beginning of the melting process (Buchwald et al., 2008). Analyses were performed in triplicate for each treatment. ...
... The thermograms of the wheat straw waxes extracted by n-hexane (Fig. 9) present complex behavior with at least three important peaks, similar to the beeswax thermogram behavior reported in the literature (Buchwald et al., 2008). Beeswax comprises a complex mixture of esters (C40-C52), alkanes (C23-C33), and fatty acids (C22-C34) (Regert et al., 2005), which is partially comparable to that observed in the wheat straw waxes. ...
Straw is a good source of vegetal waxes, which are commonly extracted using hazardous and non-renewable solvents. In this study, one to six immersion cycles in liquid nitrogen (10–60 s immersion followed by 10–60 s rest time) were employed to remove vegetal waxes from wheat and flax straw. The wax yields after six immersion cycles in liquid nitrogen were 25.8 ± 1.0 and 18.8 ± 2.7 mg per 100 g wheat and flax straw, respectively. Scanning electron micrographs helped demonstrate the selectivity of the immersions in liquid nitrogen toward the epicuticular waxes. Prior to extraction, wheat straw presented higher crystal concentrations, related to better immersion cycle wax yields. Chemical and thermal analyses confirmed that the epicuticular waxes from wheat and flax straw were purer and presented different compound proportions than the respective cuticular waxes. Thus, the wheat and flax straw cuticular waxes comprised β-diketones (40% w/w) and aldehydes (36.7% w/w), respectively, as their major compounds. On the other hand, the wheat and flax epicuticular waxes comprised β-diketones (62.9–66.8% w/w) and esters (60.2–64.6% w/w), respectively. The thermodynamic and chemical analytical data of the waxes were in concordance with each other.
... Its unique composition and properties make it a promising candidate for developing tissue-mimicking materials. Chemically, beeswax is primarily composed of esters, hydrocarbons, and free acids [6]. This complex molecular structure imparts beeswax with distinctive characteristics, such as a high melting point and malleability, facilitating its processing and shaping into desired forms [7]. ...
... Sci. 2024,14, x FOR PEER REVIEW6 The procedure of manufacturing an anthropomorphic phantom. (A) Three-dimensionally printed mold from DICOM images; (B) volume rendering reconstruction after scanning on CT; (C) axial images of phantom mold after scanning on CT. ...
Background: The development of novel medical imaging technologies and treatment procedures hinges on the availability of accurate and versatile phantoms. This paper presents a cost-effective approach for creating anthropomorphic abdominal phantoms. Methods: This study proposes a cost-effective method using 3D printing and readily available materials (beeswax, plaster, and epoxy resin) to create high-fidelity anthropomorphic abdominal phantoms. The three-dimensionally printed phantoms exhibited X-ray attenuation properties closely matching those of human tissues, with measured Hounsfield unit (HU) values of −115.41 ± 20.29 HU for fat, 65.61 ± 18.06 HU for muscle, and 510 ± 131.2 HU for bone. These values were compared against patient images and a commercially available phantom, and no statistically significant difference was observed in fat tissue simulation (p = 0.428). Differences were observed for muscle and bone tissues, in which the 3D-printed phantom demonstrated higher HU values compared with patient images (p < 0.001). The 3D-printed phantom’s bone simulation was statistically like that of the commercially available phantom (p = 0.063). Conclusion: This method offers a cost-effective, accessible, and customizable alternative for abdominal phantoms. This innovation has the potential to accelerate advancements in abdominal imaging research, leading to improved diagnostic tools and treatment options for patients. These phantoms could be used to develop and test new imaging techniques with high accuracy.
... It is well known from the literature [15] that beeswax exhibits two melting endothermic peaks upon heating: the first at around 56 °C and the second at around 68 °C. The thermal properties of samples determined by DSC are summarised In Table 4. ...
... It is well known from the literature [15] that beeswax exhibits two melting endothermic peaks upon heating: the first at around 56 • C and the second at around 68 • C. The thermal properties of samples determined by DSC are summarised In Table 4. In Figure 6a,b the DSC thermograms of the first cooling run and the second heating run are presented, respectively. ...
A stone chest found in 1971 near one of the largest early Christian basilicas in Northern Dalmatia (Croatia) contained brass tiles decorated with various biblical scenes. An archaeological study confirmed the thesis that the fragments of brass tiles are most likely the remains of a wooden chest made in the 4th century AD, and that this is one of the best preserved archaeological finds of its kind in the world as one of the biblical scenes shows Mary, together with a record of her name (Maria). Based on the preserved brass tiles, a reconstruction of the wooden chest was made in 1973 with tiles glued onto a plastic frame. Subsequent studies have shown that such a reconstruction was not adequate, as some of the brass tiles were destroyed (disintegrated), and they were not connected properly into a whole that could represent the original. For the new reconstruction of this archaeological object it was necessary to carry out a material analysis, including the chemical composition of the brass tiles, as well as to find a solvent for the glue which could be used to remove the brass tiles from the plastic framework without any additional destruction. Based on extensive investigations and material analyses including the following techniques (SEM, EDX, FTIR, DSC), the starting points for the restoration process of the wooden chest with brass tiles were set, as well as the proposal for the appearance of the new chest.
... Based on the TGA plots from the literature, pure paraffin wax can be completely consumed at a temperature of around 330-350 °C [6,28,30]. At the same time, the decomposition temperature of BW is higher than that of paraffin wax [54]. Therefore, it can be said that the thermal stability of BW is higher than that of paraffin wax. ...
... Based on the TGA plots from the literature, pure paraffin wax can be completely consumed at a temperature of around 330-350 • C [6,28,30]. At the same time, the decomposition temperature of BW is higher than that of paraffin wax [54]. Therefore, it can be said that the thermal stability of BW is higher than that of paraffin wax. ...
Beeswax (C46H92O) is a naturally derived substance that has the potential to be used as a solid fuel for hybrid rocket applications and as a substitute for paraffin wax fuel in hybrid rockets. BW burns more efficiently than paraffin wax because of the oxygen molecule it contains. The low thermal stability and poor mechanical properties of BW limit its practical use for upper-stage propulsion applications, and these issues are rarely addressed in the literature on hybrid rockets. This study investigates the thermal stability and ballistic properties of BW using ethylene-vinyl acetate (EVA) and activated charcoal (AC) as an additive. The thermal stability of BW–EVA/AC fuel compositions was analyzed using a thermogravimetric analyzer (TGA). The thermal stability of the blended BW compositions improved significantly. A laboratory-scale hybrid rocket motor was used to evaluate such aspects of ballistic performance as regression rate, characteristic velocity, and combustion efficiency. The results revealed that the pure BW exhibited a higher regression rate of 26.5% at an oxidizer mass flux of 96.4 kg/m²-s compared to BW–EVA/AC blends. The addition of EVA and AC to BW was found to increase the experimental characteristic velocity and combustion efficiency. The combustion efficiency of BW-based fuel was improved from 62% to 94% when 20 wt.% EVA and 2 wt.% AC were added into the fuel matrix.
... Fatty acids and free alcohols are frequently present in these waxes, as confirmed by this peak. For VW, this peak reduces from Day 0 to day 3 potentially due to natural losses, but reduces further upon the addition of heat (the annealing treatment), likely causing some evaporation of these alcohol groups or other impurities within the waxes (Buchwald et al. 2008). The peak position remains approximately constant for all the VW traces. ...
... The BW/CW impregnated and annealed samples in particular showed a small but steady decrease in tan delta value up to the T a-2 region, before following the upward trend of the plain paper trial from thereon in. The melting point range for a BW/CW 1:1 composition is 45-80°C (Buchwald et al. 2008;Zhang et al. 2014)). This range begins lower than the individual melting points of the waxes, in keeping with standard solid-liquid phase diagrams, but also dependent upon the eutectic point of the mixture (Yuan et al. 2016). ...
Supercritical impregnation may be used to impart specific functional properties into porous substrates such as wood, textiles, or paper. In the current study, food-grade beeswax (BW), carnauba wax (CW) and vegetable wax (VW) were impregnated into paper substrates to improve their hydrophobicity and mechanical strength. The contact angle of impregnated and annealed samples was approximately 110–120° when annealed at 140 °C, and 130° when annealed at 160 °C. SEM analyses revealed that dual micro- and nano-scale roughness was generated in impregnated paper substrates that also underwent annealing. FTIR analysis showed evidence of H-bonding between the waxes and cellulose, but this was more dominant with BW/CW compared with VW due to the different chemical structures of the waxes. Annealed samples showed lower intensity FTIR peaks, tentatively confirming a phase transition of the waxes as a result of the annealing. A reduced tan delta signal up to the secondary alpha transition temperature for paper was observed with BW/CW impregnated samples, indicating the formation of additional chemical bonds between cellulose and wax. Compared with untreated paper substrates, the sharp decrease in storage modulus during degradation occurred at temperatures up to 10 °C higher for wax-impregnated papers, and up to 40 °C lower for baseline papers impregnated and annealed without wax. It is believed that the H-bonds between the waxes and cellulose were able to withstand higher temperatures in the degradation region, thus offsetting the effects of sample preparation.
... Moreover, the difference between the melting enthalpies of the tested samples was similar to our findings (66 and 43.8 J/g, respectively). Almost the same melting temperature value of Apis mellifera wax (64.6 C) was obtained by Buchwald et al. (2008). These authors compared calorimetric data for waxes produced by various species of insects. ...
... Interestingly, they obtained much lower melting temperature values for waxes produced by bumble bees. They also observed that the melting peak of the A. mellifera wax is very broad, showing the initiation of melting at approximately 40 C (Buchwald et al., 2008). The results of thermal analysis of tested beeswax samples are also similar to those obtained by Ruguo et al. (2011) for A. mellifera wax. ...
Beeswax samples of different origins were evaluated for their authenticity by infrared spectroscopy and thermal analysis. The Fourier Transform Infrared Spectroscopy (FT-IR) method was used for the genuineness assessment and the melting process was examined using the differential scanning calorimetry (DSC) method. Eight suspicious beeswax samples delivered by local beekeepers were examined. As reference standards, pure authentic beeswax standards, pure paraffin, and wax-paraffin blends were used. The comparison of the infrared spectra of tested wax samples and references allowed the identification of adulterated wax samples based on the differences in the spectra fingerprint region (700 to 1800 cm À1), especially 1170 and 1735 cm À1 bands. Moreover, the ratio of the 1735 and 2850 cm À1 band area (lower than 0.5) was used as an indicator of wax adulteration. Among the 8 samples studied, 3 were found to have been falsified with paraffin. The thermal analysis confirmed the adulteration of the same wax samples. The melting temperatures determined in these cases were lower (52.3 to 57.7) as compared to other samples (63.1 to 65.9), identified as real beeswax by comparison to standards (63.8 to 64.7). A similar tendency during the reheating of cooled wax samples was observed, which suggested the addition of paraffin or another substance with a lower melting point to adulterated waxes. The methods used in this research (FT-IR and DSC) allowed for a relatively quick, easy, and inexpensive verification of the authenticity of the bees-wax. Such a method can be used as a screening step before a comprehensive GC analysis of beeswax.
... The measured value is very similar to waxes collected from cavity resting honeybees (i.e., Apis cerana, Apis mellifera, etc.). [47] The value is higher than the heat of fusion of industrial semicrystalline polymers such as polyesters, [48] ...
... However, other natural beeswaxes with lower enthalpy of fusion exist such as the ones synthesized by common Melipona bee species with almost identical heat of fusion values. [47] Nonetheless, the emulsion coatings encapsulate the wax very well and prevent leaching of the wax upon heating them above the melting point of wax. Therefore, a tradeoff between high heat of fusion but poor structural stability (pure wax) and good structural stability (encapsulated wax) but somewhat lower heat of fusion was established by this emulsion coating approach. ...
Beeswax particles are homogenously emulsified in commercial aqueous polymer dispersion, without additional dispersing agents and surfactants. Emulsions display very good stability with wax droplet size distribution around 350 nm. The wax to polymer ratio in the emulsions can be tuned without compromising emulsion stability. The emulsions are spray coated in order to create either hydrophobic or superhydrophobic coatings. For superhydrophobicity, silica nanoparticles are dispersed in the emulsions at different concentrations. Beeswax‐rich coatings such as the ones with 1:1 beeswax:polymer ratio or more, including the superhydrophobic ones, demonstrate promising latent heat storage characteristics, suitable for thermal management applications. Electron microscopy studies show that as a result of emulsification, the polymer encapsulates the wax droplets/particles as a nanothin shell, preventing a major problem related to low melting point phase change materials referred to as leaching. Hence, the coatings can be heated well above the melting point of beeswax (≈62 °C) and can still demonstrate effective heat storage during the cooling stage. This water‐based coating process using ecofriendly material constituents can easily be scaled up and used in responsive coating applications, ranging from electronics to interior or exterior structural buildings requiring efficient energy management and thermal energy savings.
... The presence of different peaks from the BW thermal behavior may be attributed to the heterogeneous composition of the BW matrix [15]. These peaks most likely represent the crystallization or melting of distinct BW components; each of them could be single or multicomponent in nature, such as fatty acids (12-14%), monoesters and hydroxymonoesters (35-45%), complex wax esters (15-27%), straight chain hydrocarbons (mainly C33) (12-16%), and other minor components [16,17]. The BW thermal properties obtained in this work are in agreement with those reported by Yilmaz and Ogutou [18] for commercial BW (KahlWax, Kahl GmbH, Trittau, Germany), except for ∆H c (8% smaller) and ∆H m (7.6% smaller), probably associated with different composition. ...
... Measurements were performed in triplicate and heat flow (W/g) was plotted against temperature ( • C). Onset temperature and maximum peak ( • C) were obtained from thermal curves of crystallization and melting, while enthalpy (J/g) was determined by integrating the area under each thermogram in the range 10-80 • C, using the Universal Analysis 2000 V 4.5 software (TA Instruments) [17]. ...
Nanoemulsions are feasible delivery systems of lipophilic compounds, showing potential as edible coatings with enhanced functional properties. The aim of this work was to study the effect of emulsifier type (stearic acid (SA), Tween 80 (T80) or Tween 80/Span 60 (T80/S60)) and emulsification process (homogenization, ultrasound or microfluidization) on nanoemulsion formation based on oxidized corn starch, beeswax (BW) and natural antimicrobials (lauric arginate and natamycin). The response variables were physicochemical properties, rheological behavior, wettability and antimicrobial activity of BW–starch nanoemulsions (BW–SN). The BW–SN emulsified using T80 and microfluidized showed the lowest droplet size (77.6 ± 6.2 nm), a polydispersion index of 0.4 ± 0.0 and whiteness index (WI) of 31.8 ± 0.8. This BW–SN exhibited a more negative ζ-potential: −36 ± 4 mV, and Newtonian flow behavior, indicating great stability. BW–SN antimicrobial activity was not affected by microfluidization nor the presence of T80, showing inhibition of the deteriorative fungi R. stolonifer, C. gloeosporioides and B. cinerea, and the pathogenic bacterium S. Saintpaul. In addition, regardless of emulsifier type and emulsification process, BW–SN applied on the tomato surface exhibited low contact angles (38.5° to 48.6°), resulting in efficient wettability (−7.0 mN/m to −8.9 mN/m). These nanoemulsions may be useful to produce edible coatings to preserve fresh-produce quality and safety.
... The melting transitions' end points (e.g., 64.2°C for beeswax) include the melting points of several major components, such as fatty acids and wax esters, that are present in beeswax. 57 Similar multiple melting and crystallization peaks were observed for beeswax, 58 soywax, and carnauba wax 33 in the previous literature. Comparing to petroleum waxes, paraffin wax showed the same behavior as multiple peaks for melting and crystallization. ...
... Wn: 64.71 0.02 , Wt: 63.40 0. 15 and Wf: 64.55 0.23 . These results were in line with the findings in previous studies of melting behavior of Apis mellifera beeswaxes 15,16 . ...
Beeswax is an important agricultural product in many developing countries and its quality can be affected by various factors of the harvesting and processing. This study compared the extraction yield as well as physicochemical properties of beeswax melted by different methods (solar energy and conventional method) and collected at different positions (surface of honeycomb and the old nest cakes). Obtained results showed that melting method mainly affected the recovery yield of beeswax and did not cause significant changes of chemical properties of products. However, samples collected at the surface of honeycomb seemed to have a higher quality in compared to samples collected from the old nest cakes.
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... Although beeswax samples can present DSC differences depending on the origin of the wax [18], they have a single endothermic peak with melting point above 50°C [19,20] and there are no modifications in the DSC curve after 50 heating cycles [21]. However, the Cosmetic Products and Industry -New Advances and Applications 4 so-called synthetic beeswax (wax-6) sample herein reported is different, since it has two melting endothermic peaks below 50°C and its DSC curve changes between heating cycles. ...
In this work, eight commercial eyelashes mascaras were stored during 15 days at 50°C and a correlation between visually perceived separations over time and the thermal behavior of the waxes present within each product was observed. It was found that 3 of the 8 studied mascaras, displayed noticeable separations which agreed with both changes in their DSC curves and the presence of 2 heat-sensitive waxes in their formula. Finally, it is suggested that the addition of heat-sensitive wax mixtures into a formula should be discarded in order to avoid visual phase-separations and produce thermally stable mascaras that offer the product experience designed for users.
... It could be potentially utilized as a lubricant, and investigation has shown its higher efficiency as compared to other waxes [15,16]. Natural beeswax is a non-toxic and anti-corrosive material that exhibits a high latent heat of transition (145-395 kJ/kg) and a low melting point (60-68 • C) [15,17]. Its low vapor pressure, minimal volume change and chemical stability are close to those of conventional type lubricants. ...
Abstract
Possibility to produce the biogrease using rapeseed oil as a base oil, beeswax as a thickener and its modification with functional anti-wear and antioxidant additives and carbon nanoparticles of graphene oxide and thermally expanded graphite nanoparticles were evaluated. Tribological tests were performed using a four-ball tribo-tester and the rheological characterization using a cone-plate Brookfield rheometer. The rheological parameters were correlated with the physico-chemical properties of the greases. The resulting variation of the rheological parameters with the temperature exhibits non-Newtonian behavior. Although the increasing proportion of beeswax worsens the tribological properties of investigated grease, the functional additives and nanoparticles significantly improve the thermal properties of the lubricant, yield stress, viscosity and tribological properties reducing the wear rate.
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... Differential scanning calorimetry (Q 20, TA instrument) was used to determine the thermal properties of W-paste as shown in Fig. 2f. Consistent with a prior study, melting temperature is near 64 C in the heating cycle [65]. The inset shows a detailed view of the peaks near the melting point. ...
Bioresorbable implantable medical devices can be employed in versatile clinical scenarios that burden patients with complications and surgical removal of conventional devices. However, a shortage of suitable electrical interconnection materials limits the development of bioresorbable electronic systems. Therefore, this study highlights a highly conductive, naturally resorbable paste exhibiting enhanced electrical conductivity and mechanical stability that can solve the existing problems of bioresorbable interconnections. Multifaceted experiments on electrical and physical properties were used to optimize the composition of pastes containing beeswax, submicron tungsten particles, and glycofurol. These pastes embody isotropic conductive paths for three-dimensional interconnects and function as antennas, sensors, and contact pads for bioresorbable electronic devices. The degradation behavior in aqueous solutions was used to assess its stability and ability to retain electrical conductance (∼7 kS/m) and structural form over the requisite dissolution period. In vitro and in vivo biocompatibility tests clarified the safety of the paste as an implantable material.
... In addition to the natural aging of the wax itself, other causes such as fluctuations in relative humidity and temperature have also contributed to the origin of fissures and cracks in the most vulnerable parts. This is due to the constant changes in contraction and expansion that the material has undergone in response to climate conditions (Fig. 2) [21,22]. Greatly enhanced by the multiple manipulations mentioned above, several fractures and the loss of some elements including the middle finger have occurred. ...
Three-dimensional models of anatomy in wax preserved in university museums are rare artifacts of extraordinary technical complexity. In recent years, interest in them has increased among scholars who consider them primary sources of heritage value to approach material culture and the history of science. The fragility of the sculptural material and the inadequate exhibition and storage conditions of many of these collections have caused the formation of pathologies whose conservation treatment is a great challenge for the restorer. In this regard, new 3D digital technologies have created a great impact on the documentation and analysis of interventions in the field of conservation and restoration of cultural heritage. This research aims to demonstrate the technical possibilities offered by 3D digital systems as support tools in curative conservation strategies to mechanically stabilize fragmented sculptural parts. For this case study, we chose an 18th-century obstetric anatomical model made by the Madrid Court sculptor Juan Cháez, and the modeler Luigi Franceschi who belonged to the anatomical cabinet of the Royal College of Surgery of San Carlos in Madrid. In this work, we demonstrate the digitization process carried out employing structured light scanners, digital modeling, and 3D printing. The aim is to create auxiliary structures suitable to support the various original pieces to be adhered while guaranteeing their exact position during the adhesive curing process as well as the volumetric reintegration of faults. In addition tensile and three point bending tests for the mechanical characterization of the selected thermoplastic impression materials are described. Finally, the qualities considered suitable for the most appropriate material for the purpose of the study are detailed. Promising results were obtained since the structures have made it possible to perform fragment adhesions in highly complex areas of the sculpture, ensuring maximum precision, safety, and efficiency during the process.
... The two different endothermic peaks in the propolis thermogram indicated the presence of two different types of crystals that melts at different temperature whereas the broad peaks specify the crystals having imperfection behavior with a blend of other organic crystals having a wide melting range (Matsuda et al., 2002;Charsley et al., 2006). The main endothermic peaks ranged from 60.46 to 63.92 • C mainly determines phase transition from solid to liquid that shows melting of beeswax (Buchwald et al., 2008;Zhang et al., 2012) and medium-chain saturated fatty acid (SFA) especially C-16 fatty acids (mostly palmitic acid) (Knothe and Dunn, 2009) whereas the wide temperature range of T p 1 from Onset temperature (T o ) 46.12 • C to End set temperature (T e ) 93.14 • C indicates the melting of wide varieties of medium and long-chain SFA from C 13 -C 24 (Knothe and Dunn, 2009). Additionally, T p 1 in all samples also demonstrates the evaporation of free water molecules present in the material (Sen et al., 2015). ...
First-ever, the propolis samples collected from different geographical locations of Northern India were investigated based on nutritional composition and thermal analysis. Gas chromatograph flame ionization detector (GC-FID) identified the presence of essential fatty acids: linoleic acid, α-linolenic acid, cis-11,14,17-eicosatrienoic acid, eicosapentaenoic acid, docosahexaenoic acid, γ-linolenic acid, dihomo-γ-linolenic acid, and cis-11-14-eicosadienoic acid in the samples. Additionally, first-time detection of 17 amino acids showed the presences of tyrosine, glutamic acid, threonine, arginine, lysine and aspartic acid as predominant in the samples, whereas microwave plasma-atomic emission spectroscopy (MP-AES) revealed abundance of calcium (5706.2- 3121.0 mg/kg) followed by potassium (2636.0-1615.5 mg/kg), iron (2487.0-1161.2 mg/kg) and magnesium (1573.4-841.0 mg/kg). Furthermore, differential scanning calorimetry (DSC) showed major endothermic peaks at approximately 60 ᵒC demonstrating melting of long and medium chain fatty acids especially beeswax and palmitic acid, while the secondary peaks exposed vaporization of aromatic compounds. Thermogravimetric analyzer (TGA) depicted major weight loss of propolis between 270-470 ᵒC and obtained 14.99-40.02% residual weight. Principal Component analysis demonstrated 99.18% variation in the first three principal components. Hierarchical cluster analysis categorized all the propolis samples successfully based on geographical locations. This study may assist quality control authorities to establish nutritional and quality standards of Indian propolis in future.
... The wax-resin samples being completely amorphous, as a result of its short molecules with little interaction, did not show a T g . The melting curve showed two peaks instead of one, the lower one being substantially lower than the visually observed melting point at 60 • C, in line with Robert Buchwald's observations [28]. No measurable penetration of water molecules into its wax-resin structure was visible (Fig. 5) and no essential changes in either the melting temperature T m or melting enthalpy became visible at the DSC measurements. ...
Canvas paintings are prone to environmental ageing. Hence, the structural conservation of canvas paintings may require lining, a process in which a secondary canvas is adhered to the reverse of the damaged original canvas to provide additional support. Choosing the optimum adhesive in combination with a lining method is crucial and yet challenging, as they should preferably be mechanically and chemically stable and reversible for at least 100 years. Comprehensive data on thermal and long term mechanical behaviour of prevalently used adhesives and their bonded assemblies to canvas is scarce and yet necessary to enable conservators for a proper choice of the materials in terms of durability. In this study, four prevalently used adhesives in the conservation of canvas paintings are investigated and their creep performance is evaluated and benchmarked at three different temperatures and environmental relative humidities (RHs). These adhesives are either bio-based (animal glue-starch paste and beeswax-dammar resin mixtures), or synthetic (BEVA® 371 and an aqueous PlextolTM D540/K360 dispersion mixture). Differential Scanning Calorimetry (DSC) technique is used to study the thermal transitions at different RHs. T-peel and lap shear tests are performed to determine the fracture behaviour and shear strength respectively. An in-house built creep set-up equipped with environmental control is developed which allows investigation of the mechanical creep for different canvas bonded assemblies. The results demonstrate the effects of temperature and relative humidity on the creep behaviour of lined canvases, which are related to their physical response. Moreover, the animal glue-starch paste shows the best creep mechanical performance for this application, while the PlextolTM acrylic dispersion mixture in combination with Mist-Lining is a better alternative when both environment and reversibility are considered.
... Finally, the peculiar mechanical and thermal characteristics of this substance have also attracted the attention of engineers, who are promoting studies on applied energy systems [76]. Indeed, beeswax is characterised by a latent heat of 141.49 kJ/kg and a melting point of 62.28 • C and the role of beeswax as a starting renewable raw material for thermal energy storage is promising [77]. ...
Simple Summary
Apis mellifera Linnaeus (1758), a honey bee, is a eusocial insect widely known for its role in pollination, an essential ecosystem service for plant biodiversity, and quality of vegetables and fruit products. In addition, honey bees and bee products are valuable bioindicators of pollutants, such as airborne particulate matter, heavy metals, and pesticides. In this review, we explore the provisioning, regulating, and cultural services provided by the honey bee, an insect at the interface between human and ecosystem health.
Abstract
The concept of ecosystem services is widely understood as the services and benefits thatecosystems provide to humans, and they have been categorised into provisioning, regulating, supporting, and cultural services. This article aims to provide an updated overview of the benefits that the honey bee Apis mellifera provides to humans as well as ecosystems. We revised the role of honey bees as pollinators in natural ecosystems to preserve and restore the local biodiversity of wild plants; in agro-ecosystems, this species is widely used to enhance crop yield and quality, meeting the increasing food demand. Beekeeping activity provides humans not only with high-quality food but also with substances used as raw materials and in pharmaceuticals, and in polluted areas, bees convey valuable information on the environmental presence of pollutants and their impact on human and ecosystem health. Finally, the role of the honey bee in symbolic tradition, mysticism, and the cultural values of the bee habitats are also presented. Overall, we suggest that the symbolic value of the honey bee is the most important role played by this insect species, as it may help revitalise and strengthen the intimate and reciprocal relationship between humans and the natural world, avoiding the inaccuracy of considering the ecosystems as mere providers of services to humans.
... Beeswax are primarily composed of esters, fatty acids, alcohols and hydrocarbons, linear wax monoesters, free fatty alcohols, hydroxy monoesters derived from palmitic, oleic acids, 15-hydroxypalmitic, and complex wax esters containing 15-hydroxypalmitic acid and diols (92). Beeswax are multicomponent solid mixture at room temperature (93), and used as an additive in the food industry, cosmetics, and candles (16). Beeswax is a natural biological polymer (94), which is used as a thickener, drug carrier, binder, and a release retardant in pharmaceutical preparations (95). ...
Increased demand for a more balanced, healthy, and safe diet has accelerated studies on natural bee products (including honey, bee bread, bee collected pollen royal jelly, propolis, beeswax, and bee venom) over the past decade. Advanced food processing techniques, such as ultrasonication and microwave and infrared (IR) irradiation, either has gained popularity as alternatives or combined with conventional processing techniques for diverse applications in apiculture products at laboratory or industrial scale. The processing techniques used for each bee products have comprehensively summarized in this review, including drying (traditional drying, infrared drying, microwave-assisted traditional drying or vacuum drying, and low temperature high velocity-assisted fluidized bed drying), storage, extraction, isolation, and identification; the assessment methods related to the quality control of bee products are also fully mentioned. The different processing techniques applied in bee products aim to provide more healthy active ingredients largely and effectively. Furthermore, improved the product quality with a shorter processing time and reduced operational cost are achieved using conventional or emerging processing techniques. This review will increase the positive ratings of the combined new processing techniques according to the needs of the bee products. The importance of the models for process optimization on a large scale is also emphasized in the future.
... Beeswax and colophony were stable in their solid form on the surface. The melting points were 62 • C for beeswax [32] and 70−72 • C for colophony [33]. The test solution was kept at 37 • C, far below the melting point of the beeswax-colophony components. ...
A bilayer anodic film/beeswax–colophony is proposed for improving the corrosion resistance of magnesium alloy surface. The bilayer was synthesized on the AZ31 alloy by anodization and subsequent dip coating, and the corrosion behavior was investigated by electrochemical measurements and weight loss test in Ringer lactate at 37 °C. The bilayer improved the electrochemical corrosion resistance by four orders of magnitude, as demonstrated by ~104 times lower corrosion current density in the polarization curves and ~104 higher film resistance in the impedance spectra. The tremendous surface area of the porous anodic film led to a strong attachment of the topcoat beeswax–colophony. Most of the coating remained attached to the surface after 14 days soaking in Ringer lactate. A few small blisters developed under the bilayer contributed to the low mass loss of 0.07 mg/cm2/day compared to the bare substrate, with an average loss rate of 0.25 mg/cm2/day. Local detachment of topcoat layer exposed the underlying anodic film that triggered the deposition of Ca and further nucleation of the Ca–P compound on the surface. The existence of a Ca−P compound with a Ca/P ratio of 1.68 indicated the ability of the bilayer to promote the formation of bone mineral apatite.
... The temperature program was: heating from 25 to 90 C at a rate of 20 C min −1 , isothermal at 90 C for 30 min, cooling to −30 C at a rate of 5 C min −1 . The onset of crystallization was determined during the cooling scan (Buchwald et al., 2008). Analyses were performed in triplicate. ...
Valorization of the agri-food industry by-products could contribute to curb issues related to food security and environmental problems. Flax and wheat seeds are major products of this industry, but their production is associated with tons of straws that can be valorized for their cuticular and epicuticular waxes. We aimed to determine the organogelation capacity of epicuticular waxes in comparison to cuticular waxes from both flax and wheat straws. Epicuticular waxes from flax and wheat straws have structured canola oil at 2% and 4% (w/w), respectively, whereas cuticular waxes from flax and wheat straws required critical concentrations of 4% and 5% (w/w), respectively. Characterization of the organogelation capacity (onset of crystallization temperature, temperature of phase transition, crystal morphology, solid fat, crystalline structure, and oil binding capacity) was also carried out. The high onset of crystallization temperature (38.1 1.2C), the phase transition at high temperature (38 1.5C), and capacity to structure canola oil at low concentration showed that epicuticular wax from flax straw is a promisor fat substitute, presenting organogelation properties comparable to the best results obtained in the literature for other vegetal waxes.
... In contrast to most insects and birds, bees construct their nests from their own secretions. Although other species of eusocial bees (such as bumblebees and stingless bees) mix their wax with other foreign substances (such as plant resins and pupal silk) during nest construction, honeybees are quite unique among them in using their pure glandular wax for nest building [7] normal worker bee possesses eight pairs of wax glands under their abdomen that produce small flat wax scales up to 3 mm long and 0.5 mm deep. When such a worker bee creates comb, she scrapes a wax scale from her abdomen using the spines on her pollen bas- ket and passes them to her front legs. ...
The absolute perfection with which honeybees construct their hexagonal comb cells astonished human beings from ancient times. The deep mystery lies not on why hexagons but on how such a perfect geometrical shape is fabricated without having any geometrical portrait or tools. Do they possess divine intelligence? Recent studies shed light on such a revered mystery and show beyond doubt that it is the thermo-mechanical properties of beeswax and the knitting mechanism of bees that remould the fresh circular cells into a rounded hexagonal shape. How does this remoulding happen? In this article, we describe the inner mechanism involved in such spontaneous transformation of shapes and point out where the actually hidden mystery lies in honeybee’s architecture.
... To produce high-grade paper cups, the lignin content, which is an undesirable polymer in paper making, should be as low as possible [23]. Its removal during pulping requires high amounts of chemicals and energy [24]. In addition, a higher lignin content implies that the cellulosic fibers are bonded more tightly together [25]. ...
While past studies have been carried out to form eco-friendly disposable tableware using non-wood biomass, there is no present groundwork so far where fruit peels waste composited with Mauritian hemp (Furcraea foetida) has been used for such purpose, which is novel to this research work. This study therefore assesses whether the production of 100% biodegradable disposable paper cups with acceptable strength properties using pineapple (Ananas comosus) peels, orange (Citrus sinensis) peels and Mauritian hemp as feedstock is feasible. Soda pulping followed by vacuum molding was done to produce hemp:pineapple peels and hemp:orange peels composite paper cups in different ratios. The cups were tested using relevant standards in terms of appearance and structure, burst strength, tensile strength, weight load, water leakage and biodegradability to find the optimum cup composition by comparing with a suitable control. All cups were visually conformant in terms of color and base stability. The 40:60 hemp–pineapple peels composite cup had characteristics closest to the control, with no cracks and variation rate of weight load, average thickness of 1.42 mm and burst and tensile indexes of 0.25 kPa m2/g and 3.30 Nm/g, respectively. Beeswax coating thickness of 0.70 mm on the optimum cup was adequate to retain cold water for 30 min (minimum) without any leakage. The cup also biodegraded completely in both active soil and damp sand environments within 5 and 6 weeks, respectively. Results therefore reveal that fiber extraction from fruit peel wastes and hemp leaves to produce eco-friendly, biodegradable disposable paper cups is viable.
... In addition, the materials are inexpensive, and their scalable design lends itself to high volume production. For the first layer, natural wax healing materials such as beeswax [20][21][22] , palm wax and carnauba wax were chosen based on representative daytime temperatures in Thailand. The layer was fabricated using a melt coating process in a pan coater. ...
In this work, bio-inspired concepts, including a Self-Healing (SH) and super hydrophobic structure, were used to produce slow-release of urea fertilizer. Following a bottom-up process, an SH layer on the urea granule was produced from a combination of two natural waxes, palm and carnauba, and fabricated by a hot-melt coating process in a pan coater. Another layer for super hydrophobicity was formed by a deposition of submicron-wax and carbon black particles on the SH layer to create a micro-nanostructure during coating. After the heat treatment, a smooth coating and even deposition of waxes throughout the urea surfaces were obtained. The properties of the waxes, a healing mechanism, and releasing profiles were examined using an optical microscope. After cracking of the coated urea surface, the intrinsic self-healing behavior was stimulated by heating the samples above 45 °C, corresponding to high ambient daytime temperatures. Air-trapping behavior was observed at the interphase of the water and coated urea, creating super hydrophobic granule surfaces which act as an invisible layer for water-penetration protection. The releasing profiles of the coated urea in soil revealed that the releasing periods could be significantly extended to four-times longer than those of the uncoated urea.
... [16] The easiest method to induce crystallization is by cooling the sample to the optimum temperature for nucleation and crystal growth. [15][16][17] Based on the properties described above, increased crystallization of epicuticular waxes may help to improve the wax yield during immersion cycles in liquid nitrogen. The aim of this work was to assess the effect of temperature-controlled storage as a pretreatment for wheat and flax straw prior to wax extraction by cyclic immersion in liquid nitrogen. ...
Flax and wheat straw were stored at −20°C, 4°C, or 20°C for up to 28 days as a pre-treatment to wax extraction performed using n-hexane or by immersion in liquid nitrogen. The epicuticular wax separation yield improved significantly after 28 days of storage at 4°C for both flax and wheat samples. Controlled-temperature storage resulted in a loss of selectivity in regard to epicuticular wax recovery from flax straw. Alterations within the epicuticular waxes that occurred during controlled-temperature storage were analyzed using scanning electron microscopy. Thermal analysis of the waxes using DSC yielded findings that were in concordance with the chemical results.
... Table 1 lists the composition of the three waxes utilized in this study, as reported by Doan et al. (2017), two of which (BW and CLW) were from the same vendor as used in the current study. BW has been reported to contain WE, hydroxyl esters, HC, diesters, FFA, as well as other minor components (Buchwald et al., 2008;Doan et al., 2017;Tulloch, 1970). The main components, shown in Table 1, were WE (58%) composed mainly of C16 fatty acids and C24-C32 FAL, HC (27%, mainly C27-C31), 9% FFA, and 6% FAL. ...
To be able to tailor and optimize the physical properties of oleogels for various food applications, more information is needed to understand how different gelators interact. Therefore, the objectives of this study were to evaluate the interactions between binary mixtures of beeswax (BW), candelilla wax (CLW), and sunflower wax (SFW) in pure form as well as in 5% wax oleogels made with soybean oil, in terms of their crystallization and melting properties, crystal morphology, solid fat content, and gel firmness. CLW:BW mixtures had eutectic melting properties, and oleogels from these mixtures with 40:60 to 90:10 CLW:BW were firmer compared to oleogels made with one wax. The main components in SFW and BW appeared to cocrystallize or crystallize at the same temperature, but nonlinear changes in melting point and solid fat content profile of oleogels prepared with the mixed waxes indicated that SFW dominated oleogel formation. In addition, oleogels prepared with mixtures of SFW and BW had lower firmness compared to oleogels prepared with one wax, indicating an incompatibility between the two waxes. The main wax components in SFW and CLW never cocrystallized, and low levels of CLW appeared to prevent SFW from forming a crystalline platelet network. This resulted in low firmness of oleogels made from mixtures of 90:10 to 60:40 SFW:CLW compared to oleogels prepared with one wax. However, the firmest oleogels of all mixtures were made from 10:90 SFW:CLW. Changes in gel firmness and melting properties with mixed wax oleogels were likely to be due to changes observed in the crystal size and morphology. In addition, the firmest gels were shown to result from mixtures that were predicted to have >40% hydrocarbon content, and a high hydrocarbon to wax ester ratio, but minor components such as free fatty acids and fatty alcohols may have also influenced firmness.
... Moreover, the heat of fusion decreased by 26.04 J/g after 1000 cycles, although it increased after 500 cycles. This behavior may be due to the changes in the complex composition of beeswax as the beeswax absorbed and released heat [23]. ...
A recently developed method for the thermal stability measurement of phase-change materials (PCMs) involves thermal cycling using a thermoelectric module as a heating and cooling element. However, the utility of this approach was found to have some limitations, mainly because the thermoelectric polarity is changed according to time rather than the actual sample temperature. A method for thermal cycling test, where the thermoelectric polarity is automatically changed according to the sample temperature was developed in this study. In addition, a new cartridge design in this device requires a small sample volume (1.53 cm³) and can be easily assembled and disassembled. This proposed device was tested on beeswax as a PCM sample. This is very important for savings PCMs material which usually expensive. The results showed that the apparatus had automatically cycled between the melting and cooling temperatures of beeswax. The thermal data showed that beeswax retains consistent melting and freezing temperatures after 1000 cycles, however, its heat of fusion degrades over repeated thermal cycling. This apparatus can be readily applied to study a wide range of PCMs for such as thermal energy storage materials for energy conservation. To our best knowledge, yet no study has been performed on this kind of equipment so far.
... Methods for honey bee silk research employing various molecular, spectroscopic and chromatographic analytical tools (Campbell et al., 2014;Sutherland et al., 2007Sutherland et al., , 2011Sutherland et al., , 2014Walker, Warden, Trueman, Weisman, & Sutherland, 2013;;Weisman et al., 2010;Wittmer et al., 2011), and ESEM (Zhang, Si, Duan, & Wang, 2010). Method for research on thermal properties of beeswax based on classical melting point determination, determination of the heat of fusion, differential scanning calorimetry (DSC), and thermal conductivity determination (Buchwald et al., 2005;Buchwald, Breed, & Greenberg, 2008;Timbers & Gochnauer, 1982;Timbers, Robertson, & Gochnauer, 1977). ...
Due to its multifunctional and complex role in the honey bee colony functioning and health (construction material allowing food storage, brood rearing, thermoregulation, mediation in chemical and mechanical communication, substrate for pathogens, toxins and waste), Apis mellifera beeswax has been widely studied over the last five decades. This is supported by a comprehensive set of scientific reports covering different aspects of beeswax research. In this article, we present an overview of the methods for studying chemical, biological, constructional, and quality aspects of beeswax. We provide a detailed description of the methods for investigating wax scales, comb construction and growth pattern, cell properties, chemical composition of beeswax using different analytical tools, as well as the analytical procedures for provenancing beeswax and beeswax-derived compounds based on the hydrogen isotope ratio (IRMS). Along with classical physico-chemical and sensory analysis, we describe more precise and accurate methods for detection of adulterants in beeswax (GC-MS and FTIR-ATR). Moreover, we present methods for studying the influence of beeswax (comb foundation) adulteration on comb construction. Analytical protocols for determining the pesticide residues using different chromatographic and spectroscopic techniques are also described. As beeswax is an agent of high risk for the transmission of bee diseases, we present methods for detection of pathogens in beeswax. To ensure the reproducibility of experiments and results, we present best practice approaches and detailed protocols for all methods described, as well as their advantages and disadvantages.
Métodos estándar para la investigación de la cera de abejas Apis mellifera
Debido a su papel multifuncional y complejo en el funcionamiento y la salud de la colonia de abejas melíferas (material de construcción que permite el almacenamiento de alimentos, la cría, la termorregulación, la mediación en la comunicación química y mecánica, el sustrato para patógenos, toxinas y desechos), la cera de las abejas Apis mellifera ha sido ampliamente estudiada en las últimas cinco décadas. Esto se apoya en un amplio conjunto de informes científicos que abarcan diferentes aspectos de la investigación sobre la cera de abejas. En este artículo presentamos una visión general de los métodos que permiten el estudio químico, biológico, estructural y cualitativo de dicha cera. Proporcionamos una descripción detallada de los métodos usados para la investigación de las escamas de cera, la construcción del panal y su patrón de crecimiento, las propiedades de las celdas, y la composición química de la cera utilizando diferentes herramientas analíticas; así como los procedimientos analíticos basados en el ratio de isótopos de hidrógeno (IRMS) que permiten determinar el origen de la cera y los compuestos derivados de ella. Junto con el análisis físico-químico y sensorial clásico, describimos métodos más precisos y exactos para la detección de adulterantes en cera de abejas (GC-MS y FTIR-ATR). Además, presentamos métodos para estudiar la influencia de la adulteración de la cera de abejas (base del panal) en la construcción del panal. También se describen protocolos analíticos para determinar los residuos de pesticidas utilizando diferentes técnicas cromatográficas y espectroscópicas. Dado que la cera de abejas es un agente de alto riesgo en la transmisión de enfermedades de abejas, presentamos métodos para la detección de patógenos en dicha cera. Para garantizar la reproducibilidad de los experimentos y los resultados, presentamos modelos de buenas prácticas y protocolos detallados para todos los métodos descritos, así como sus ventajas y desventajas.
西方蜜蜂蜂蜡研究标准方法
蜂蜡在蜂群功能和健康中具有多种功能和复杂作用（食物储存、哺育幼虫、温度调节的筑巢材料, 化学和机械通讯的中介, 以及病原体、毒素和废物的基质）, 因此西方蜜蜂蜂蜡在过去五十年中被广泛研究。这得到了一套全面科学报告的支持, 涵盖了蜂蜡研究的不同领域。本文概述了蜂蜡的化学、生物、结构和质量的研究方法。本文详细介绍了利用不同分析工具研究蜡鳞、筑巢, 蜂蜡的生长方式、细胞特性和化学成分的方法, 以及基于氢同位素比值 (IRMS) 的蜂蜡和蜂蜡衍生化合物的来源分析方法。除了经典的物理化学和感官分析, 我们还描述了更精准的检测蜂蜡掺假的方法（GC-MS和FTIR-ATR）。此外, 我们还研究了蜂蜡（巢础）造假对蜂巢结构的影响。还介绍了使用不同色谱和光谱技术测定农药残留的分析流程。由于蜂蜡是传播蜜蜂疾病的高危因素, 我们提出了检测蜂蜡中病原体的方法。为了确保实验和结果的可重复性, 我们为所描述的所有方法提供了最佳实践方法和详细流程, 以及它们的优缺点。
... The effect was almost outweighted by the natural variability of beeswax properties. Its melting temperature typically lies within the interval of 61-66°C and the specific enthalpy of fusion fluctuates from 150 to 205 J g −1 (Powers, Craig, and Peyton 1969;Tulloch 1980;Wolfmeier et al. 2000;Buchwald, Breed, and Greenberg 2008;Gaillard et al. 2011;Yao and Wang 2012;Cavallaro et al. 2015;Martini, Tan, and Jana 2015). However, it should be noted that the width of the intervals reflects not only the natural variability of the parameters, but also different methods used by independent laboratories. ...
Mechanical properties of aged beeswax were studied by an indirect measurement, using hydrogenated beeswax as a model material. The adequacy of the model was evaluated by comparison of its chemical composition and thermal properties with those of samples of historical beeswax. It was found that the gradual decrease in content of unsaturated compounds in beeswax contributes significantly to changes of its mechanical properties. As a consequence, beeswax artefacts become increasingly prone to mechanical damage during natural ageing. Understanding the difference between mechanical properties of recent and historical beeswax is primarily important from the point of view of safe handling and storage of such artefacts. Besides, this knowledge could help conservation scientists, e. g. when preparing model samples for testing new conservation methods.
... Natural polymers usually made up of polysaccharides or proteins are hydrophilic, enzymatically degradable. 2 Polymers like Beeswax are hydrophobic in nature which is inert and biodegradable. It has good hemocompatibility and high interaction with living cells making them compatible and suitable biomaterials for long systemic circulation and targeting. ...
... The wax identified on the surface could correspond to residual traces of a surface treatment postdating the excavation of the site to protect the surface from alteration. In fact, if an original wax coating was applied on the surface of these wall paintings soon after their completion, this would have not survived the high temperatures (natural beeswax melts at 64 • C, starts to vaporize at ∼ 200 • C and completely decomposes at ∼ 500 • C [72,73]) of the pyroclastic density currents that destroyed and buried the ancient Pompeii (180-380 • C [74]). ...
The materials and techniques of wall paintings decorating the Domus of Octavius Quartio,
an outstanding patrician villa in ancient Pompeii, were investigated by means of a multi-analytical and non-invasive approach. Chemical and mineralogical characterization of pigments was obtained by the combined use of external reflection Fourier Transform infrared spectroscopy (ER-FTIR), sequentially shifted excitation Raman spectroscopy (SSR-RS) and portable X-ray fluorescence (XRF) spectroscopy. ER-FTIR and SSR-RS provided complementary molecular information for the characterization of both organic and inorganic pigments and helped to identify the pigments in the white, red, yellow, black, blue and pink paints. XRF spectroscopy provided elemental characterization of the inorganic pigments and assisted in the determination of pigment mixtures mainly
constituting the green paints. Results pointed to the use of a characteristic Roman palette, consisting of calcite, cinnabar, red and yellow ochre, green earths, Egyptian
blue and carbon black. A fresco application of the pigments was suggested for the execution of the wall paintings. The combined approach by spectroscopic techniques also recognized that wax had been applied as a consolidant or protective coating, and weathering products in the form of gypsum and calcium oxalate also occur.
Aim: The aim of this study was to optimize, develop, characterize and evaluate a topical nanobigel (BG) formulation containing Berberine (BRB) that exhibits anti-melanogenic properties. Materials & methods: The Berberine-loaded bigel (BRB@BG) formulation was prepared by homogenously mixing the optimized hydrogel and oleogel. BRB@BG was characterized in vitro and cytotoxicity study was conducted to evaluate its effects on murine skin melanoma B16F10 cell lines. Results: The optimized BRB@BG exhibited uniform texture with nanometric size, desirable spreadability and extrudability, suitable for topical applications. Cytotoxicity studies revealed that BRB@BG had a lower IC50 value (4.84 μg/ml) on B16F10 cell lines compared with drug alone. Conclusion: In conclusion, the developed BRB@BG formulation showed good potential as safe and effective topical treatment for hyperpigmentation.
Starch is an appealing natural polymer for the scaled‐up production of biodegradable plastics. However, the low water resistance of starch has made its broad applicability largely doubted. In this study, starch was combined with beeswax (BW) through a pilot scale continuous solution casting (CSC) technique to reduce water affinity while keeping the ensuing films totally biodegradable. The phase morphology, surface wettability, and water vapor permeability (WVP) of films were examined over a broad BW–starch mass ratio (0.3–0.7). Emulsified, surfactant‐free starch/BW films were successfully obtained at a productivity of 0.55 m² film h⁻¹. The water contact angle increased nearly by 100% at 30 wt% BW, leading to remarkable reductions in WVP. BW droplets well distributed within the starch matrix played a key role in enhancing the water barrier properties of films. CSC of starch/BW films offers a basis to design new hydrophobic formulations for applications that require biodegradable plastics with high moisture resistance.
The typical of beeswax, dammar, rosin, paraffin, and microcrystalline wax. batik wax compositions used in Malaysia consist of various blends This study aims to characterize soy wax/beeswax blends’ structural, thermal, strength, and mass loss properties as potential alternative batik wax compositions. The Fourier transform infrared spectroscopy (FTIR) results showed that the additions of beeswax (wt%) into soy wax resulted in possible chemical interaction for the esters (C=O stretching and C-H bending vibrations), hydrocarbons (CH2 scissor formation), and cholestral esters (C=O stretching vibrations). The thermal profile obtained via differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) respectively revealed an increase in peak melting temperature and reduced thermal stability of the blends with further increments of beeswax. In addition, beeswax enhances the compression strength by 150% but did not have any significant impact on the modulus of the blends. E valuation of the mass loss test suggested that beeswax in the range of 40 wt% to 60 wt% can be considered as alternative batik resist material due to its moderate leaching tendency. Future works shall be conducted to evaluate the performance of these wax compositions against other batik wax criteria and the feasibility of printing these waxes using an in-house designed batik printer.
Some bee species use wax to build their nests. They store honey and raise their brood in cells made entirely from wax. How can the bee brood breathe and develop properly when sealed in wax cells? We compared the chemical composition and structural properties of the honey cappings and worker brood cappings of the honeybee Apis mellifera carnica, measured the worker brood respiration, and calculated the CO2 gradients across the two types of cappings. We identified microscopic pores present in the brood cappings that allow efficient gas exchange of the developing brood. In contrary, honey cappings are nearly gas impermeable to protect honey from fermenting. Similar principles apply in bumble bees. Our data suggest the control of gas exchange of cappings as a selective pressure in the evolution of wax-building bees that drives their adaptation for using wax in two highly contrasting biological contexts.
Honeycomb is one of nature's best engineered structures. Even though it has inspired several modern engineering structures, an understanding of the process by which the hexagonal cells are formed in 3D space is lacking. Previous studies on the structure of the honeycomb are based on either 2D microscopy or by direct visual observations. As a result, several critical features of its microstructure and the precise mechanisms of its growth are not well understood. Using 4D X‐ray microscopy, this study shows, how individual and groups of honeycomb cells are formed. Cells grow additively from a corrugated central spine in a dynamic manner. The previously undocumented, corrugated spine contributes significantly to the comb's robust mechanical properties in all three dimensions. As cells grow, honey bees create a “coping”, which this study shows to be the location where new wax material is deposited behind which compaction and densification take place. This is exemplified by pores in the wax observed at the coping and alternating rear junctions between the comb cells that arise from the additive building technique and the highly efficient cell packing methodology, respectively. Additional mechanisms for growth and formation are discussed and described. This article is protected by copyright. All rights reserved
The industry demands high quality and standards-compliant beeswax, which is difficult to find in western countries. As a result, it is necessary to explore new geographical sources. This work focuses on the characterization of beeswax from Mozambique in terms of saturated hydrocarbon profile and thermal properties comparing them with others from diverse origins. The hydrocarbons found (C21H44-C35H72) do not contain enough information for its differentiation. However, melting and cooling enthalpies together with all the temperatures associated with the different lipid polymorphic forms achieved this goal. A higher average melting enthalpy values obtained in Mozambique samples (up to 234 J/g) and Honduras (231 J/g) indicates more energy is required to melt these beeswaxes than those from Spain (193 J/g) and an analytical reactive pure beeswaxes considered as “reference” (168 J/g). This might be linked to the tropical temperatures where the bees produce specific wax. These results are significant in characterizing beeswax from tropical climates and for the industry to exploit its peculiar properties.
https://exarc.net/issue-2020-3/mm/short-guide-making-wax-tablets.
Insects build myriad structures out of diverse materials. These structures serve purposes that range from facilitating prey capture to housing their entire colony. Whereas some insects operate solitarily, others collectively build large and complex structures. The architecture of these structures vis-à-vis their ultimate function poses fascinating questions that require multidisciplinary investigations. Importantly, because the underlying design and architectural principles have evolved over millions of years to withstand multitude of environmental perturbations, they offer important lessons for human-made structures. The vast variety of insect-built structures reflects how diverse insects have adapted to resolve the ecological challenges in their specific habitats. Here, we survey insect-built structures from a comparative perspective to ask what design and architectural principles can be gleaned from them. We discuss the key hypotheses about building-behaviours, their neural underpinnings, the functional role of insect-built structures and their biomimetic potential.
Using beeswax as wrapping matrix, two types of release-controlled TM (thiamethoxam)/BK(beeswax-kaolin) microcapsules were prepared by adsorbing TM on kaolin and then encapsulated with beeswax, or directly wrapping TM with beeswax. The structure and morphology of the TM/BK microcapsules were characterized. The effects of different preparation methods, the particle size, pH conditions and different additives on the release property of the TM/BK microcapsules were investigated in water and soil column to compare the advantages of the two approaches. Finally, the insecticidal effect of the TM/BK microcapsules against sugarcane borer and rice planthopper was tested. The results show that the TM/BK microcapsules have a better sustained-release in both water and soil, and the release rate is different under different pH conditions. In addition, the releasing time of the TM/BK microcapsules can be modified by different preparation methods and combination of different additives. In the field applications, the insecticidal activity of the TM/BK microcapsules was better than that of non-sustained control group. Especially in the rice field test, 45 days after the application, the control group lost the activity against rice planthopper because of drug loss, whereas the TM/BK microcapsule group still retained about 90% of the insecticidal activity. The results suggest that the microcapsules have better agricultural application for insect control.
The construction of honeycombs astonished human being from ancient time due to their perfect geometrical structure. How the hexagonal cells are constructed from fresh circular cells during the cell building process is a matter of long debate. Here we show solely from the thermomechanical properties of self-synthesized beeswax how the honeybees permanently transform the fresh circular cells to rounded hexagons by creating a temperature gradient in the vicinity of the triple junctions of circular cell walls. By assuming conventional Fourier’s law of heat conduction and mechanical properties of beeswax, we show via computer simulations that with increasing temperature gradient, the stress on the adjacent circular cell walls increases due to enhanced fusion, leading to the deformation from the original positions of the circular cell walls. The calculated von Mises stresses are found to be significantly larger than the yield stress, indicating the permanent deformation of the circular cell walls to rounded hexagonal shape. This suggests that it is the thermomechanical properties of the building material for which the comb cells take rounded hexagonal shapes.
Hypothesis
Previous experimental work has shown that microcapsule walls, made by solidification of a molten wax, are unexpectedly permeable. The hypothesis was that this was due more to the structure of the wall than the material itself.
Experiments
The permeability of thin (sub and low micron thickness) natural waxes was measured where a membrane was placed between two cells and the diffusion of a dye (fluorescein) measured. A filter paper was used to support the membranes. Two methods were used to coat the filter paper; simple dipping and spin coating. The resulting surfaces were examined using SEM, XRD and contact angle.
Findings
Results indicate that the permeability of very thin walled capsules can be investigated by forming a layer on a porous support and measuring diffusion rates. Both the composition of the wax and the sample preparation is extremely important to the structure and resulting permeability of the membranes. Spin coating was much more effective than dip coating in reducing permeability. Carnauba wax had a much lower permeability than beeswax.
A difference in levels between the two cells was observed, indicating a potential Osmotic pressure difference at play which should be further investigated.
An ointment is a semisolid preparation consisting of a single external phase in which liquid or solid substance(s) can be dispersed. In the case of beeswax ointments, there are several studies that confirm their antibiotic and healing power over injuries, especially in those caused by burns. Beeswax can be used also as an oil phase for the production of soaps by saponification. Soaps that contain beeswax have many advantages: they solidify quickly, provide detergency and cleaning properties, give a solid and pleasant texture and their aroma can be improved by adding natural essences. In this work, dermocosmetic ointments and soaps based on beeswax and sesame oil were formulated implementing the “Reproducing an Innovation Environment in the Classroom” (RAIS) strategy at the Chemical Engineering School at Universidad de Los Andes. Beeswax purification procedures were applied and sesame oil - beeswax formulations were obtained. In this sense, soaps were manufactured at the same concentrations as the ointments were formulated. Studies of pH, foamability and formulation scans were made to determine interfacial properties of the soaps produced. http://erevistas.saber.ula.ve/index.php/cienciaeingenieria/article/view/13719
In this study, pure beeswax and its novel composite with expanded graphite (10% wt.) were tested for thermal storage efficiency in a rectangular shell and helical tube storage unit. Low thermal conductivity of beeswax is improved by adding expanded graphite of 10% wt. Thermal characterization of beeswax and its composite was performed using differential scanning calorimetry and thermogravimetric analysis. Effect of hot fluid flow rates (0.25 liter per minute [LPM], 0.5 LPM, and 1.0 LPM) and inlet temperatures (60ºC, 70ºC, and 80ºC) on the charging time of beeswax and its composite was studied and compared. Charging time of beeswax and its composite reduced with an increase in fluid flow rate and inlet temperature. At 0.5 LPM flow rate and 80°C inlet fluid temperature, the charging time of composite was reduced by 630 min as compared to pure beeswax. Smaller charging time, improved thermal conductivity, and better thermal storage efficiency of composite material suggest it as a useful storage material for a wider range of applications.
Abstract ‐ Capped brood ( capped within 36 h) and adult workers of Apis dorsatawere removed,from naturally occurring colonies and kept incubated in laboratory hoarding cages at constant tempera- tures ranging from 26 to 45 ,C. Nest temperature control is critical for survival of brood of A. dorsataand adult worker bees have tight constraints on their abilities to endure high tem- peratures. Water availability is vital for cooling the colony under hot, tropical conditions, and rearing healthy brood. Apis dorsata/ optimal temperature/ thermoregulation/ tropical Asia/ brood/ workers
Vibration of the rims of open cells in a honeycomb, applied in the plane of the comb face, is transmitted across the comb. Attenuation or amplification of the vibratory signal depends on its frequency and on the type of comb. In general, framed combs, both large and small, strongly attenuate higher frequencies, whereas these are amplified in small open combs. The very poor transmission properties of the large framed combs used in commercial hives may explain the bees' habit of freeing an area of comb from the frame in those areas used for dancing. Extracellular electrical recordings from the leg of a honeybee detect large action potentials from receptors that monitor extension of the tibia on the femur. Measurements of threshold displacement amplitudes show these receptors to be sensitive to low frequencies. The amplification properties of unframed combs extend the range of these receptor systems to include frequencies that are emitted by the bee during its dance, namely the 15 Hz abdomen waggle and 250 Hz thorax vibration.
Beeswax is a multicomponent material used by bees in the genus Apis to house larvae and store honey and pollen. We characterized the mechanical properties of waxes from four honeybee species: Apis mellifera L., Apis andreniformis L., Apis dorsata L. and two subspecies of Apis cerana L. In order to isolate the material effects from the architectural properties of nest comb, we formed raw wax in to right, circular cylindrical samples, and compressed them in an electromechanical tensometer. From the resulting stress-strain curves, values for yield stress, yield strain, stress and strain at the proportional limit, stiffness, and resilience were obtained. Apis dorsata wax was stiffer and had a higher yield stress and stress at the proportional limit than all of the other waxes. The waxes of A. cerana and A. mellifera had intermediate strength and stiffness, and A. andreniformis wax was the least strong, stiff and resilient. All of the waxes had similar strain values at the proportional limit and yield point. The observed differences in wax mechanical properties correlate with the nesting ecology of these species. A. mellifera and A. cerana nest in cavities that protect the nest from environmental stresses, whereas the species with the strongest and stiffest wax, A. dorsata, constructs relatively heavy nests attached to branches of tall trees, exposing them to substantially greater mechanical forces. The wax of A. andreniformis was the least strong, stiff and resilient, and their nests have low masses relative to other species in the genus and, although not built in cavities, are constructed on lower, often shielded branches that can absorb the forces of wind and rain.
The specific heat of three samples of clean cappings wax, determined by conventional calorimetry, was 0·484±0·0153 cal g−1 °C−1. Determined by differential scanning calorimetry of two similar samples, the specific heat varied with temperature from 0·4187 to 0·5014 cal g−1 °C−1 over the range −3° to +17°, and from 0·5275 to 0·5517 cal g−1 °C−1 over the range 77° to 97°.Differential thermal analysis and differential scanning calorimetry on 3 paraffin, 1 microcrystalline and 5 beeswax varieties yielded well formed reproducible thermogram peaks. Little difference was observed between thermograms of the various processed and unprocessed beeswax varieties. Thermograms of beeswax-paraffin mixtures reflected the influence of both waxes. Paraffin was readily detectable at the 5% level in paraffin-beeswax mixtures.
Analysis of the nest material of T. australis by gas chromatography/chemical ionization-mass spectrometry showed the wax to comprise a hydrocarbon fraction (90%), esters (6%) and free acids . (4%). The major saturated hydrocarbons were C27, C31 and C33 with C2S and C29 being less abundant and C23 and C 3S being present in small amounts. Traces of the intermediate, even-numbered homologues were also found. Hydrocarbons (C31o C 33 and C 3S) which contained one double bond were also present and traces of the diene C3S were detected. The ester fraction did not contain compounds identical with those in beeswax made by the honeybee Apis melli/era and the acid fractions were also quite different. T. australis wax contained the following, saturated free acids: CIO (trace), C12, C14, C16, CIS and C20, monoenoic and dienoic CIS and C 20 and traces of the trienoic CIS. The wax of T. australis is colourless but the brown colour of the nest material derives from the inclusion of masses of pollen (Eucalyptus sp.) and solid material from the inside of the nest tree. The solid residue comprised between 12 and 30% by weight.
Plaster composites have been developed by the authors, aiming the manufacture of plasterboards and other building materials with enhanced properties. Polymeric plaster composites,obtained from hydration of commercial plaster of Paris with aqueous solutions of a commercial polyester, were characterized by thermogravimetry (TG) and differential thermal analysis (DTA). A method using derivative thermogravimetry (DTG) was developed to determine the polymer content in the composites and its distribution. Samples prepared conventionally by hydration of plaster of Paris with water were used as reference. Independently of the initial solution concentration, all the composites show an even distribution of the polymer, which presence enhances the composite mechanical strength.
Lubricating and fuel oils can be characterized for their low-temperature specifications with better repeatability and reproducibility than the standard pour point and cloud point methods. These low-temperature tests are non-destructive and can be followed by using the same sample for measuring the high-temperature thermal stability of the oil (DSC destructive test). The oil sample can be as small as 10 mg. The presence of pour point depressant additives separated the wax crystallization DSC effect (exotherm) from the wax melting effect (endotherm), and also produced heat-flow effect in the higher temperature region.
A review is presented of recent developments of the combustion of single droplets with the object of stimulating discussion and future work in the field. Among the areas covered are the combustion of stationary and moving droplets in an oxidising atmosphere, the combustion of monopropellants, the influence of high pressures and the ignition of droplets. The application of droplet theories to the modelling of various combustion systems is also outlined.
The mechanical properties of beeswax, measured as a function of temperature, using a variety of techniques, are identified and compared. The coefficient of friction of beeswax is measured and compared with that of plasticine and Nylon 6–6. It is shown that the frictional behaviour of beeswax departs from Amonton's laws and behaves instead as a classic soft, elastic polymer. Free surface energy measurements of beeswax are also reported.
Petroleum waxes from sixteen different crude oils were analyzed after isolation from the crude in a two-step process. These waxes were characterized molecularly to aid in the investigation of the effect of wax type and quantity on water-in-crude oil emulsion stability. The techniques used to gather information about the waxes included elemental analysis, FTIR spectroscopy, field desorption mass spectroscopy, 1H NMR spectroscopy, 13C NMR spectroscopy, gel permeation chromatography, and differential scanning calorimetry. Two distinctly different types of petroleum waxes were discerned, microcrystalline and paraffinic. Microcrystalline waxes are aliphatic hydrocarbon compounds containing a substantial amount of branches and rings. They have large molecular weight ranges from 300 to 2500 amu and are gel-like in appearance. The rings give rise to a decreased H/C ratio relative to paraffinic waxes, often as low as 1.85. Because of the large number of different compounds and the lack of large-scale crystallinity, a distinct melting regime is not observed. FTIR spectroscopy determined that these waxes contained approximately 55% straight chain methylene, that is, methylene groups directly attached to each other. Five waxes exhibited these characteristics and thus were considered typical microcrystalline waxes. Paraffin waxes are hydrocarbon chains with few or no branches and H/C ratios between 1.96 and 2.05. They have distinct melting regions and narrow molecular weight ranges between 350 and 600 amu. They contained 63−78% straight chain methylene as gauged by FTIR spectroscopy. Six of the remaining eleven waxes exhibited all the characteristics of this paraffin category while the other five were mixtures of microcrystalline and paraffinic wax.
Waxes are important as building material and for the chemical communication of the honeybee Apis mellifera carnica. In this study chemometric tools were established for classifying the different waxes inside the hive. By using gas chromatography in combination with mass spectrometry, components of different types of waxes were analyzed. By considering different substance classes of waxes, discriminant function analyses revealed distinct subtypes of comb waxes and of cuticular waxes. It is shown that the aging of comb wax is in part a spontaneous physicochemical process due to differential volatilities of compound classes with different chain length ranges. On the other hand it is directly influenced by the bees by adding lipolytic enzymes to the comb wax. The data suggest that the varying cuticular wax and comb wax compositions could serve as cues for bees to recognize castes, sexes, or comb age.
This review deals, with waxes of members of two quite different groups of insects, the bees and the scale insects, which secrete
large amounts of wax. The former use was as a structural material and the latter as a protective material. The compositions
of waxes from some of these insects are described and particular attention is paid to the compositions of the unhydrolyzed
waxes and to the presence of hydroxy acids. New analyses of beeswax and of wax of a species of bumble bee are reported. The
structures of the diesters, hydroxyesters and diols of beeswax are elucidated. The bumble bee wax contains major proportions
of saturated and unsaturated hydrocarbons, and of long chain saturated, mono- and diunsaturated esters. The relationship between
structure and function of the waxes is discussed.
Wax comb was found to have a thermal conductivity of 0.3610–3 cal/cm sec C. At low air temperatures, honey bees,Apis mellifera L., form clusters inbetween the combs in their nests. The combs provide insulation and the bee behavior actually increases the insulating effectiveness of the combs. When they form a compact living layer over the wax comb, the conductivity can be reduced to 0.06510–3 cal/cm see C. Some aspects of the role of the wax comb in heat balance are examined in this paper.
1.
The conversion of virgin beeswax scales into finished comb wax has been analysed by crystallographic, mechanical and chemical
means.
2.
The effects of mandibulation by the honeybees are to transform the texturally anisotropic scale into planar isotropic comb.
3.
Both waxes contain proteins. They differ in gross lipid composition.
4.
The saliva added to the wax by the bees contains material with very probable lipolytic activity that reduces the diglyceride
pool of the scale wax with a corresponding increase in the monoglyceride fraction of the comb wax.
5.
The combined effects of the crystallographic and chemical changes on the mechanical properties of the wax are as follows.
Scale wax is as strong at 23°C as comb wax but the latter has twice the stiffness and is less distensible than the former.
The energy to fracture comb wax (an index of the work bees must invest to shape it) is only half that of scale wax over the
range of temperatures likely to impinge upon the nests of honeybees.
Young virgin queens of the stingless bee Melipona bicolor have been shown to produce wax like workers. The small, white to transparent flakes of wax of the queens protrude from the intersegmental space and cover the anterior part of the tergite cuticle, in a way similar to that in workers. This points to the presence of wax glands in the queens. However, workers produce wax from glands located at the fourth to seventh tergites whereas queens secrete wax from the epidermal gland at the third tergite only Analysis of the queen-produced wax showed that it contains the same substances as the worker-produced wax with minor differences in composition. The wax consists chiefly of the long-chain esters triacontanyl acetate and octacosanyl acetate, smaller amounts of linear C-21 to C-31 alkanes and alkenes, and still smaller quantities of linear aldehydes and isobutyrate esters. Analysis of wax from wax deposits and wax constructs showed the same composition. Wax from M. bicolor is similar to that of other stingless bees in containing the range of linear long-chain alkenes and alkanes and different from that of Apis bees which contains a more complex mixture, less hydrocarbons and more long chain esters.
1.1. The wax of Trigona (Trigonisca) buyssoni and T. (T.) atomaria is much simplier in composition than that of Apis mellifera and consists of hydrocarbon (59.3 ± 3.5% and 70.9 ± 6.3%, respectively, by wt), wax monoester (26.8 ± 3.5% and 25.5 ± 6.3%), free fatty acid (5.4 ± 1.6% and 1.7 ± 0.9%), primary alcohol (7.0 ± 2.4 and 1.0 ± 0.9%), and unidentified more polar material (1.5 ± 0.1% and 0.3 ± 0.5%). No diols, hydroxy acids or their esters were detected in the wax of Trigona.2.2. The hydrocarbons in both species range in chain length from C21 to C37 and consist of n-alkanes (90.2% and 87.1%), alkenes (8.4% and 12.4%) and methyl branched alkanes (1.4% and 0%).3.3. The wax esters contain primary alcohol moieties of C16 to C30 in which tetracosanol, hexacosanol and octacosanol are major components.4.4. The fatty acid portion of the wax esters have chain lengths of 12 to 30+ carbons with 18:1 comprising over 30% of this fraction.5.5. The majority of free primary alcohols range from C24 to C30 in both species with C24, C26 and C28 components predominating.6.6. Major free fatty acids in the wax of both species are 16:0, 18:0 and 18:1.
Incluye Bibliografía e índice
The combwaxes of the honeybee species Apis mellifera, Apis cerana, Apis dorsata, Apis laboriosa, Apis florea and Apis andreniformis have been examined by high-temperature gas chromatography. Combwax consists of a complex mixture of homologous neutral lipids. These compounds containing up to 64 carbons were chromatographed intact on a 10 m x 0.2 mm high-temperature stable SOP-50-PFD (50%-diphenyl/50%-1H,1H,2H,2H-perfluorodecylmethylpolysiloxane)-co ated Duran glass capillary column. The use of this stationary phase results in lower retention values and, at last, in lower thermal stress of the analytes. In order to minimize the discrimination effect due to adsorption and/or degradation, a two-step derivatization was performed resulting in the formation of tert.-butyldimethylsilyl esters of the long chain fatty acids and trimethylsilyl ethers of complex hydroxyesters, respectively. The derivatization procedure was optimized using a modification of the extended Donike test. In addition this test allows the quantification of the thermal stability of the derivatives performed. The derivatization procedure was applied for combwax analysis. More than 80 compounds were separated and their peak areas semiquantitatively exploited.
Crude combwax of six various honey bee species have been analyzed by high-temperature gas chromatography (HTGC)-chemical ionization mass spectrometry after a two-step silylation procedure. An optimized chromatographic procedure, described previously, enables the separation of high-molecular mass lipid compounds resulting in a characteristic fingerprint of the combwaxes of different honeybee species. The coupling of HTGC to mass spectrometry requires appropriate instrumentation in order to achieve sufficient sensitivity at high elution temperatures and avoid loss of chromatographic resolution. Chemical ionization was carried out using methane as reagent gas in order to determine the molecular mass of the individual compounds by means of abundant quasi molecular ions. To confirm the presence of unsaturated wax esters, ammonia was used as reagent gas. More than 80 lipid constituents were separated and characterized by their mass spectra. Representative chemical ionization mass spectra of individual compounds are presented. Both, HTGC-flame ionization detection data and the results of the HTGC-mass spectrometric investigations enabled a rapid profiling of the individual classes of compounds in crude combwaxes.
Micro-Raman spectroscopy and Raman mapping are applied to investigate the spatial distribution and chemical composition of wax and propolis in the comb of Apis mellifera carnica (Pollm). A thick layer of propolis at the rim of some cells is identified by Raman spectroscopy. Raman mapping is applied to resolve the distribution of propolis and wax on a micron scale. Both components are connected at the rim of the cell with a mixture of wax and propolis. A layer of almost pure propolis is found on top of the mixture. It appears that even in the mixture, where both components come into close contact, the propolis and the wax remain separated and keep their chemical identity.
Regulation of temperature in the nests of social insects
- T Seeley
- B Heinrich
Seeley, T. and Heinrich, B. (1981). Regulation of temperature in the nests of social insects. In Insect Thermoregulation (ed. B. Heinrich), pp. 159-234. New York: Wiley and Sons. Southwick, E. E. (1985). Thermal conductivity of wax comb and its effect on heat balance in colonial honey bees (Apis mellifera L.). Experientia 41, 1486-1487.
The ductility of native beeswax is optimally related to honeybee colony temperature
- R H Hepburn
- E Armstrong
- S Kurstjens
Hepburn, R. H., Armstrong, E. and Kurstjens, S. (1983). The ductility of native beeswax is optimally related to honeybee colony temperature. S. Afr. J. Sci. 79, 416-417.
Investigations on the physical and chemical properties of beeswax Wax chemistry of 2 stingless bees of the Trigonisca group
- C S Bisson
- G H Vansell
- W B Dye
- G J Blomquist
- D W Roubik
- S L Buchmann
Bisson, C. S., Vansell, G. H. and Dye, W. B. (1940). Investigations on the physical and chemical properties of beeswax. USDA Tech. Bull. 716. Blomquist, G. J., Roubik, D. W. and Buchmann, S. L. (1985). Wax chemistry of 2 stingless bees of the Trigonisca group (Apididae, Meliponinae). Comp. Biochem. Physiol. 82B, 137-142.
Investigations on the physical and chemical properties of beeswax
- C S Bisson
- G H Vansell
- W B Dye
Bisson, C. S., Vansell, G. H. and Dye, W. B. (1940). Investigations on the physical
and chemical properties of beeswax. USDA Tech. Bull. 716.