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The Studies on Hydrophilic-Lipophilic Balance (HLB): Sixty Years after William C. Griffin's Pioneer Work (1949-2009)
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6° piso (1113) Buenos Aires, Argentina. SUMMARY. The Hydrophilic-Lipophilic Balance (HLB)was formally presented by William C. Griffin sixty years ago at a meeting in Chicago for the first time and later on in an article published in the first volume of the Journal of the Society of Cosmetic Chemists. In later publications, Griffin proposed formu-las for the HLB value calculation that are satisfactory for non-ionic surfactants of various types. Several experimental methods developed then in order to obtain the HLB values of surfactants and required HLB of oils in a way simpler than with Griffin's original experimental method. Also there were proposed math-ematical equations that HLB values of surfactants allows to calculate from its chemical formulae and also from quality control data of surfactants and its components.
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... Among all of the processes that reflect the instability of emulsion coalescence of droplets is a characteristic irreversible process of their final separation. And the results of changes in the lifetime of the elementary emuls correlate well with the data on the strength of interfacial layers [15,16 studying the coalescence of emulsions is important for determining th properties of the EAGO emulsifier. Increasing the proportion of the new additive EAGO in paraffin from 1 to 5% reduced the value of the interfacial tension at the water-oil interface from 52.3 to 23.6 mN/m, indicating sufficient surface activity. ...
... Among all of the processes that reflect the instability of emulsions, only the coalescence of droplets is a characteristic irreversible process of their final destruction-separation. And the results of changes in the lifetime of the elementary emulsion droplets correlate well with the data on the strength of interfacial layers [15,16]. Therefore, studying the coalescence of emulsions is important for determining the functional properties of the EAGO emulsifier. ...
... The HLB number is an indicator of the effectiveness of the use of emulsifiers. The HLB is expressed by the ratio of the sizes of the polar and nonpolar parts of the surfactant molecule [8,9,15,16]. HLB values vary in the range of 0 to 20. ...
... The formation of the emulsion is facilitated by the use of emulsifiers that act as surfactants, stabilizing the emulsion by reducing the surface tension between the two liquids thanks to their polar groups, which are hydrophilic, and their non-polar groups, which are hydrophobic [7,48]. Surfactants can be categorized by taking into consideration the value of the analogy of the hydrophilic to the hydrophobic groups, known as hydrophilic-lipophilic balance (HLB), a term first proposed by Griffin in 1949 [49]. ...
... The HLB value of surfactants is a determining factor for the production of different types of emulsions [49][50][51] that have different efficiencies as vaccine adjuvants [7]. Emulsifiers with low HLB values lead to the creation of water-in-oil emulsions (W/O), whereas those with high HLB values tend to form oil-in-water emulsions (O/W) that are typically better tolerated but exhibit weaker immune responses [7]. ...
Vaccine adjuvants are crucial for reinforcing the immunogenicity of vaccines. Therefore, they are widely used in the aquaculture sector as vaccine components, facilitating the efficient prevention of infectious diseases and promoting sustainable teleost fish growth. Despite their benefits, there has been a growing concern about the potential adverse effects of vaccine adjuvants in teleost fish, connoting a valid impact on their overall health and welfare. Among the adjuvants used in aquaculture vaccinology, nanoparticle-based formulations have given rise to a promising new alternative to traditional options, such as oil-based emulsions and aluminum compounds, offering the benefit of minimizing relevant side effects. The aim of this paper was to review the current status of the adjuvants used in aquaculture, provide a description and an evaluation of their mode of action and side effects, and explore the potential use of nanoparticle formulations as adjuvants to improve the efficacy of aquaculture vaccines. By demonstrating and assessing the equilibrium between teleost fish welfare and immunological efficacy, this review presents a collective perspective that will assist in establishing a framework for the utilization of effective species-specific practices around adjuvant use in aquaculture, while also addressing the challenges of welfare-friendly immunization.
... La afinidad relativa de un tensoactivo por las fases continua y dispersa se conoce como valor HLB (Hydrophilic-Lipophilic Balance). Es una escala arbitraria (Pasquali et al. 2009;Nollet et al. 2019) de 0 a 20 en orden creciente de menos lipofílico (0) a más hidrofílico (20). Se calcula según la ecuación 2 (Nollet et al. 2019). ...
... THF was used as the mobile phase with a flow rate set at 1 mL min −1 . [40,41], represents an equilibrium relationship between the hydrophilic and lipophilic groups in surfactants concerning their size and strength. In this study, the HLBs of the polyacrylates were determined using the aqueous titration method developed by Greenwald [42]. ...
Optical instruments require extremely high precision, and even minor surface contamination can severely impact their performance. Peelable coatings offer an effective and non-damaging method for removing contaminants from optical surfaces. In this study, an amphiphilic polyacrylate copolymer (PMLEA) was synthesized via solution radical copolymerization using the lipophilic monomer lauryl acrylate (LA) and hydrophilic monomers ER-10, methyl methacrylate (MMA), and butyl acrylate (BA). The structure and molecular weight of the copolymer were characterized using Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), and gel permeation chromatography (GPC). The hydrophilic–lipophilic balance, surface tension, and wettability of the copolymer were analyzed through water titration, the platinum plate method, and liquid contact angle tests. The cleaning performance of the copolymer coating on quartz glass surface contaminants was evaluated using optical microscopy and Ultraviolet-Visible Near-Infrared (UV-Vis-NIR) spectroscopy. The study examined the effect of varying the ratio of LA to ER-10 on the hydrophilicity, lipophilicity, cleaning efficiency, and mechanical properties of the copolymer coating. The results showed that when the mass ratio of LA to ER-10 was 1:2, the synthesized copolymer exhibited optimal performance in removing dust, grease, and fingerprints from quartz glass surfaces. The coating had a tensile strength of 2.57 MPa, an elongation at break of 183%, and a peeling force of 2.07 N m−1.
... The water number of surfactants is the amount of water that a surfactant can incorporate to create a microemulsion. The determination of water number provides insights into the hydrophilic properties of surfactants and their interaction with water [1][2][3][4][5][6][7] . ...
Surfactants have a significant role in everyday life and various industries. Their amphipathic nature significantly influences their properties, functions, and applicability. The ratio of water and oil solubility is characterized by the HLB value (hydrophilic-lipophilic balance) or the closely related water number.
A determination of the water number of surfactants represents the amount of water that a surfactant can incorporate into a microemulsion. The results of measuring the water number provide information about the hydrophilic properties of the surfactant in question. Understanding the water number helps determine the applicability of surfactants. From the water number of surfactants, conclusions can be drawn about the HLB value of the particular surfactant, providing further insights into its properties. Although a well-established method for determining water number has long been available, it has been revealed that many of the auxiliary substances and chemicals used in this process have severe health-damaging effects, leading to their discontinuation in routine laboratory use.
Our goal was to find a solvent combination that would be suitable for the water number determination method. Additionally, we aimed to investigate solvents that are environmentally and human-biologically less harmful, easily and affordably obtainable.•The study presents a method for determining the water number of surfactants.
•The method is straightforward to execute and free from harmful solvents.
•By improving the method, we enhanced the reliability of the examination.
This study investigates the correlation between the hydrophilic–lipophilic balance (HLB) values and the π–A isotherm parameters of surfactant monolayers composed of sorbitan esters, specifically sorbitan monopalmitate, sorbitan tristearate, sorbitan monooleate, and sorbitan sesquioleate. The surfactant mixtures were prepared, and their π-A isotherms were recorded. The HLB values calculated for each mixture were in the range 2.10–6.70. The HLB values were compared to compression parameters, including the ratios of the slopes and the ratios of the intercepts, which were between 0.19 and 4.00 and between 0.64 and 1.77, respectively, across the monolayer compression stages. The findings indicate a significant relationship between HLB values and isotherm parameters, particularly for systems with sorbitan monooleate and sorbitan sesquioleate. A value of determination coefficient of 0.95 was found for the linear equation representing the slope ratios as a function of HLB, whereas the intercept ratios, as a linear function of HLB, gave a lower value of 0.71. The results allow for the use of the π–A Langmuir isotherm to experimentally estimate the value of the HLB in mixtures of the sorbitol esters of fatty acids, whose value is an important parameter in the selection of optimized topical and transdermal formulations, highlighting the specific formulations that enhance active substance delivery while minimizing skin irritation potential.
The hydrophilic–lipophilic balance (HLB) is a valuable parameter used to determine the relative hydrophobicity of a compound based on its chemical structure. This semi-empirical parameter has been instrumental in formulating oil-in-water and water-in-oil emulsions using well-characterized ingredients with known HLB values. However, recent trends toward the use of minimally processed “virgin” oils of therapeutic or nutritional value may render the reported “required HLB” values inaccurate. Minimally processed oils can contain numerous compounds at varying or unknown concentrations, rendering the HLB value incalculable. Factors such as regional source, growing season, and processing method contribute to the variability in oil composition. Furthermore, the solubilization of lipophilic bioactives in oils can significantly alter the HLB of the oil phase in a concentration-dependent manner. This complicates the formulation of emulsions, as the HLB values of both the oil phase and emulsifiers must be closely matched to achieve stable formulations. This study presents a simple and efficient experimental method to determine an HLB value of a complex ingredient without resorting to lengthy Design-of-Experiment (DoE) matrices and trial-and-error approaches. The optimal HLB of a formulation can be determined from a series of experiments in which two well-characterized surfactants of known HLB values are mixed at varying proportions with an unknown oil phase, where the HLB of the oil is considered to match the HLB value of the surfactants combined at the proportion at which nanoemulsions with the smallest, most stable oil droplets are formed. Similarly, when the HLB values of the oil phase and other contributing components are precisely known, the unknown HLB of a complex natural surfactant can be calculated. These calculations assist in formulating emulsions efficiently and effectively by ensuring optimal compatibility among all the components.
Preservation of foods, along with health and safety issues, is a growing concern in the current generation. Essential oils have emerged as a natural means for the long-term protection of foods along with the maintenance of their qualities. Direct applications of essential oils have posed various constraints to the food system and also have limitations in application; hence, encapsulation of essential oils into biopolymers has been recognized as a cutting-edge technology to overcome these challenges. This article presents and evaluates the strategies for the development of encapsulated essential oils on the basis of fascination with the modeling and shuffling of various biopolymers, surfactants, and co-surfactants, along with the utilization of different fabrication processes. Artificial intelligence and machine learning have enabled the preparation of different nanoemulsion formulations, synthesis strategies, stability, and release kinetics of essential oils or their bioactive components from nanoemulsions with improved efficacy in food systems. Different mathematical models for the stability and delivery kinetics of essential oils in food systems have also been discussed. The article also explains the advanced application of modeling-based encapsulation strategies on the preservation of a variety of food commodities with their intended implication in food and agricultural industries.
RÉSUMÉ Un système basé sur la température d'inversion des phases (TIP) pour la sélection des agents émulsionnants a été développé et comparé au systéme de la valeur HLB. Le rapport hydro-lipophile (HLB) d'un agent de surface non-ionique change avec la température et provoque l'inversion des phases d'une émulsion, quand les deux propriétés sont égales. La TIP varie avec les conditions d'essais el fournit des informations concernant les types d'huiles, le volume des phases, la concentration des agents émulsionnants, l'effet de la température etc. La valeur HLB ne fournit pas d'informations pareilles. La TIP est également en relation étroite avec d'autres propriétés. ZUSAMMENFASSUNG Ein Phasen-Inversions-Temperatur (PIT)-System wurde zur Auswahl eines Emulgators entwickelt und verglichen mit dent HLB-Wert System. Das hydro-lipophile Verhältnis (HLB) eines nicht ionischen Tensids verändert sich mit der Temperatur and bewirkt die Phasenumkehr einer Emulsion, wenn beide Eigcnschaften gleich sind. Die PIT variiert mit den experimentellen Bedingungen und ermöglicht Informationen über Öltypen, Phasenvolumen, Konzentration der Emulgatoren, Temperatureffekt etc. Der HLB-Wert liefert keine solchen Informationen. Die PIT steht auch in enger Beziehung zu andern Eigenschaften.
Hydrophilic lipophilic balance (HLB) values for various commercial nonionic surfactants have been determined by means of high
resolution NMR. The results are in good agreement with given HLB values. The method is rapid, nondestructive and requires
only small samples.
To study the additivity of the HLB values of an oil mixture from its component and the characteristics of the oil mixture forming a component of the emulsion, the required HLB values of several oil mixtures were determined by means of the emulsification tests proposed by Griffin.
The oil mixtures examined in this series of experiments consist of two oils, one being a mineral oil of fixed components and the other an oil to be studied as the additive, which is added in varying ratios to the fixed-component mineral oil.
The additivity of the required HLB values in oil mixtures was shown to hold to some extent for the case of saturated fatty acids, n-fatty alcohols, and some acetylated esters. For the rest of the additives, the additivity is not valid.
The required HLB values of these additive oils were remarkably large in the case of fatty acids, alcohols and some acetylated esters, excepting the anomalous value for oleic acid.
The structural effects on the increase of required HLB values seem to be in the following order:
COOH>OH>COOR
The goals of this articles are to find a correlation between the required HLB values and the solubility parameters of oils; find a more precise correlation between the required HLB values and the dielectric constant, than the one obtained by other authors; and to determine the required HLB values for o/w emulsions of solid fatty acids and alcohols from the values of the solubility parameters and dielectric constants, that could be more trustful than the ones obtained by the methodology proposed by Griffin. It was obtained lineal relation between required HLB and solubility parameter (r = 0.995). Also it was observed lineal relations between required HLB and dielectric constants or logarithm of the dielectric constant more precise than the one obtained by other authors.
Many of the criticisms of the HLB concept are based on the failure of different mixtures of emulsifier all having the same HLB number to exhibit the same emulsion stability. This failure is attributed here to the partitioning of emulsifiers into the aqueous and oleic phases and the resultant variation of the interfacial HLB number. A new set of mixing rules for nonionic emulsifiers which maintain a fixed interfacial HLB number is shown to be in accord with experiment.
The titration by water of a dioxane-benzene solution of an oil or a surface active agent to a cloud end point can be used to determine a value related to the hydrophile-lipophile balance character of the oil or surface active agent. Details of such a titration are given and the method is compared with other rating procedures.
Measurement of the relative retention time of a pair of liquids, one polar and one nonpolar, permits determination of the
polarity of the liquid Chromatographic substrate. It is shown that this polarity is a measure of the hydrophile-lipophile
balance (HLB) when the substrate is a surface-active agent. The effects of structure, additivity in mixtures, and free polyol
are discussed. A GLC apparatus, designed, to permit the rapid determination of HLB by this technique, is described.