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Optical, electrical, and mechanical properties of functionalized polymer nanocomposites
... Hybrid nanocomposites incorporating various nanostructures into polymer matrices are gaining significant attention in material science due to their enhanced multifunctional properties. [1][2][3][4][5] Recent studies have addressed various topics, including the regulatory aspects and impact modification techniques of polymers-based blends, IPNs, and gels, highlighting their industrial applications and advancements. 6,7 Other areas of focus include greener synthesis approaches for polymer-based carbon dots, cross-linking methods for biomedical nano gels, 8 the influence of sulfonated groups on proton and methanol transport in irradiated membranes, 9 and the in situ polymerization of magnetic polymer nanocomposites, demonstrating the breadth of research in materials science and nanotechnology. ...
This study focuses on the synthesis, characterization, and application of a novel polyvinyl chloride (PVC)/carbon nanotube (CNT)/zinc oxide (ZnO) hybrid nanocomposite. ZnO nanostructures with two distinct morphologies (nanohexagons and nanorods) were synthesized and embedded within a PVC matrix alongside CNTs to achieve a functional hybrid composite. TEM analysis revealed the presence of both nanohexagon and nanorod ZnO structures alongside CNTs. SEM and EDX analyses confirmed the uniform distribution of ZnO nanostructures and CNTs within the PVC matrix. FTIR and UV–vis analyses revealed successful integration of CNTs and ZnO, exhibiting well-defined morphologies with a high aspect ratio. The optical properties are characterized by a reduction in the optical bandgap from 5.40 eV for PVC/ZnO to 4.60 eV for PVC/ZnO/5%CNT, indicating an increase in absorption in the visible spectrum. Furthermore, the AC conductivity demonstrates significant frequency dependence, with conductivity increasing with CNT concentration due to the formation of conductive pathways. The dielectric constant also shows enhanced values with increased CNT content, attributed to improved interfacial polarization. The simulation of electric field distribution reveals that the PVC/CNT/ZnO nanocomposite exhibits a more uniform electric field distribution than conventional PVC. This study concludes that the PVC/CNT/ZnO nanocomposite has potential applications in optoelectronics devices.
The primary challenge in the development of sublimation inkjet inks lies in achieving a uniform, low particle size, and stable dispersion of pigments. This study addresses this issue by exploring the incorporation of sodium naphthalene sulfonate formaldehyde polymer (SNF) as a co-dispersant. Sublimation inkjet inks must maintain a particle size below 200 nm to ensure optimal printing behavior. The investigation focuses on the impact of SNF incorporation in the dispersion process of direct red 60 pigment and its optimum usage level. Results indicate that the presence of SNF in the formulation, at a concentration of 20% by weight of dye, optimizes ink behavior during dispersion. Comprehensive analysis techniques such as rheological characterization, turbidity monitoring over time, UV–Vis spectroscopy, filterability measurement, and dynamic light scattering analysis demonstrate the superior performance of the SNF-treated sample with SNF to dye weight ratio of 20% in achieving stable, uniform, and low particle size dispersion of pigment in the ink as well as flowability and rheological properties. However, further evaluation from the perspectives of printability and transfer yields unexpected findings. Contrary to the conventional assumption that inkjet inks with better dispersion exhibit superior overall performance in the final printing product, the SNF-treated sample with the tiniest and most uniform particle size and the highest flowability shows inferior performance in the transfer process. Colorimetric analysis of printed samples on transfer paper and polyester fabric reveals that sample with the tiniest particle sizes and the highest flowability penetrates deeper into the transfer paper, hindering their effective transfer to the fabric, especially at low transfer temperatures. In other words, while SNF exhibits a desirable effect on sublimation inkjet ink formulation, its optimal usage level must be carefully optimized, considering not only dispersion quality but also the colorimetric aspects of the final printed product. This underscores the importance of a nuanced approach to formulation optimization to achieve optimal printing performance in sublimation inkjet printing on polyester fabrics.
Automobile bodywork, wall insulation, bridges, and ship hulls, to name a few, are among the many applications for glass fiber-epoxy composites. To manufacture lightweight products for aforesaid applications, the properties of glass fiber-epoxy composites must be improved. The present work aims to fabricate and characterize nanoclay epoxy composites (NECs) and nanoclay glass fiber epoxy composites (NGFEC) by varying nanoclay weight percentages (i.e., 0, 2, and 4 wt.%). NECs are fabricated by a general-casting technique, and NGFECs are fabricated by hand layup technique. Flexural, impact, flammability, and water absorption tests are conducted to evaluate the properties of NECs and NGFECs in accordance with ASTM standards. The addition of nanoclay increases the flexural and impact strengths of NECs and NGFECs by 8 to 14% and 16 to 29%, respectively. Also, nanoclay additions decline the burning rate and water uptake (%) of NECs and NGFECs by 6 to 23% and 6 to 30%, respectively. The impact strength of pure epoxy, NECs, GFEC, and NGFEC is diminished by 7 to 25% at the end of 70 days of water absorption. Scanning electron microscopy images are employed to learn the causes of specimen failure under an impact load for as-made and water absorbed conditions. Crack deflection, pinning, and arresting, fiber pull-out, crazing and matrix rupturing, shear leaps are observed in the SEM images.
Conducting polymers (CPs) have been gathering a great interest in academia and industry by providing the opportunity of combining the electrical properties of a semiconductor and metals with the traditional advantages of conventional polymers such as easy and low cost preparation and fabrication. In this review we examined the conducting polymers-based composites for supercapacitor and batteries, such as conducting polymer-based binary, ternary, and quaternary composites. For their applications in energy storage field, we critically review the development of their applications and the general design rules for energy storage devices including supercapacitors, lithium and other-ions batteries, and their current limitations and future potential to advance energy storage technologies. It is expected that this review will help to improve the knowledge about this conducting polymer and consequently lead to new research fields.
Herein, the review aims to compile some reportable work of researchers carried concerning the use of nanomaterials in the polymeric composites for significant improvements in the properties and to report the application areas of such nanocomposites. Carbon nanotubes, cellulose nanoparticles, titanium dioxide, and other nanoparticles are used in the polymeric composites to enhance their mechanical, electrical, inter-laminar, optical, chemical, electrochemical, electromagnetic shielding, and ballistic properties. Such nanocomposites have a wide range of applications in structural, biomedical, electronics, automobiles, aircraft, oil pipelines, gas pipeline construction, electromagnetic shielding, and protected areas. According to the reported results of researchers, the incorporation of nanomaterials into polymers significantly enhance their properties, which make them able to widen their application areas.
Nanocomposites with polymer matrix offer excellent opportunities to explore new functionalities beyond those of conventional materials. TiO2, as a reinforcement agent in polymeric nanocomposites, is a viable strategy that significantly enhanced their mechanical properties. The size of the filler plays an essential role in determining the mechanical properties of the nanocomposite. A defining feature of polymer nanocomposites is that the small size of the fillers leads to an increase in the interfacial area compared to traditional composites. The interfacial area generates a significant volume fraction of interfacial polymer, with properties different from the bulk polymer even at low loadings of the nanofiller. This review aims to provide specific guidelines on the correlations between the structures of TiO2 nanocomposites with polymeric matrix and their mechanical properties. The correlations will be established and explained based on interfaces realized between the polymer matrix and inorganic filler. The paper focuses on the influence of the composition parameters (type of polymeric matrix, TiO2 filler with surface modified/unmodified, additives) and technological parameters (processing methods, temperature, time, pressure) on the mechanical strength of TiO2 nanocomposites with the polymeric matrix.
Conducting polymers are extensively studied due to their outstanding properties, including tunable electrical property, optical and high mechanical properties, easy synthesis and effortless fabrication and high environmental stability over conventional inorganic materials. Although conducting polymers have a lot of limitations in their pristine form, hybridization with other materials overcomes these limitations. The synergetic effects of conducting polymer composites give them wide applications in electrical, electronics and optoelectronic fields. An in-depth analysis of composites of conducting polymers with carbonaceous materials, metal oxides, transition metals and transition metal dichalcogenides etc. is used to study them effectively. Here in this review we seek to describe the transport models which help to explain the conduction mechanism, relevant synthesis approaches, and physical properties, including electrical, optical and mechanical properties. Recent developments in their applications in the fields of energy storage, photocatalysis, anti-corrosion coatings, biomedical applications and sensing applications are also explained. Structural properties play an important role in the performance of the composites.
Thin-film flexible solar cells are lightweight and mechanically robust. Along with rapidly advancing battery technology, flexible solar panels are expected to create niche products that require lightweight, mechanical flexibility, and moldability into complex shapes, such as roof-panel for electric automobiles, foldable umbrellas, camping tents, etc. In this paper, we provide a comprehensive assessment of relevant materials suitable for making flexible solar cells. Substrate materials reviewed include metals, ceramics, glasses, and plastics. For active materials, we focus primarily on emerging new semiconductors including small organic donor/acceptor molecules, conjugated donor/acceptor polymers, and organometal halide perovskites. For electrode materials, transparent conducting oxides, thin metal films/nanowires, nanocarbons, and conducting polymers are reviewed. We also discuss the merits, weaknesses, and future perspectives of these materials for developing next-generation flexible photovoltaics.
In recent years, experimentation on organic conducting polymers has been escalated and many interested researchers are looking forward to exploring more in the area of optoelectronics. Due to advantageous properties including easy tunability, flexibility, processability, thermal stability, and electroluminescence, conducting property seen to have diverse applications, but in here focus is specifically on optoelectronic devices such as OLEDs, solar cells, field-effect transistors, sensors, photo-detectors, supercapacitors, lasers, lithium-ion batteries, and various electrochromic devices. The present review focuses on conducting polymers and enhancement of its properties via functionalization, present scenario, and future prospectus of applications of conducting polymers in optoelectronic devices.
The work targets to fabricate and characterize “nanoclay–epoxy composites” (NECs) by varying weight percentages (wt.%) of nanoclay. Mechanical stirrer and sonicator are used to mix nanoclay into epoxy resin. The mixture is molded to prepare specimens in accordance with ASTM standards. The addition of nanoclay increased the mechanical properties of fabricated composites. Scanning Electron Microscopy (SEM) images revealed the causes of specimen failure. Four factors viz., nanoclay wt.%, speed, load, and time at three levels are considered a wear test on a pin-on-disc machine. The design of experiments (Taguchi design) is applied for the experimentation, and analysis of variance is established through Minitab 19 software. Results revealed that the nanoclay addition improved the resistance to wear of epoxy.
Extensive efforts have been devoted during the last decade to organic solar cell research that has led to remarkable progress and achieved power conversion efficiencies (PCEs) in excess of 10%. Among the existing flexible organic solar cells, ultrathin organic solar cells with a total thickness <10 µm have important advantages, including good mechanical bending stabilities and good conformability. These advantages have led to power generation solutions for wearable electronics. In this essay, the progress of flexible and ultrathin organic solar cells, and the future research directions pertaining to these cells are discussed based on the potential applications of textile‐compatible solar cells. Both process engineering and development of the material of ultrathin substrate films have improved the PCE of ultrathin organic solar cells, which in turn have led to the small PCE difference between flexible organic solar cells with substrate thickness >10 µm and ultrathin organic solar cells with substrate thickness ≤10 µm. Key technologies for the further improvement of PCE of flexible/ultrathin organic solar cells are discussed. Strategies to improve the stability and some important aspects, which determine the mechanical robustness of flexible organic solar cells, are also presented and discussed.
The main purpose of this study is to complete the research process of dispersing nanoclay I.30E (montmorillonite) into epoxy Epikote 240 by mechanical method combined with energy-saving ultrasonic method. We investigate appropriate dispersion conditions such as stirring speed, mechanical stirring temperature, ultrasonic stirring time, and ultrasonic stirring capacity, which affect the mechanical properties and fire resistance of nanocomposite materials. The nanoclay contents studied were 1, 2, 3, and 4% by weight, and the methods used in this study are FE-SEM; XRD; and flame-retardant evaluation methods: LOI, UL 94HB. The mechanical properties were studied: tensile strength, flexural strength, compression strength, and impact resistance Izod. The dispersion method was recommended to stir mechanically at a speed of 3000 rpm at 80°C for 8 hours and then conduct ultrasonic vibrations for 6 hours at 65°C. The results showed that epoxy Epikote 240/nanoclay I.30E nanocomposite material had mechanical properties and improved fire retardancy with a small amount of nanoclay I.30E added (2% by weight): tensile strength of 63.5 MPa (increased by 13.59%), flexural strength of 116.80 MPa (increased by 34.63%), compressive strength of 179.67 MPa (increased by 15.11%), impact resistance Izod of 12.81 KJ/m2 (increased by 80.16%), oxygen limit of 23.7%, and combustion rate of 24.5 mm/min; according to UL 94HB, the combustion rate reached 22.59 mm/min.
In this work, a poly(1-trimethylsilyl-1-propyne) (PTMSP) mixed-matrix membrane was fabricated for the selective removal of 1-butanol from aqueous solutions through pervaporation. Silica nanoparticles (SNPs), which were surface-modified with surfactant hexadecyltrimethylammonium bromide (CTAB), were incorporated into the structure of the membrane. The modified membrane was characterized by thermogravimetry-differential scanning calorimetry (TG-DSC), contact angle measurements, and scanning electron microscope (SEM) analysis. It was found that the surface hydrophobicity of the membrane was improved when compared to neat PTMSP by contact angle measurement. It was confirmed by SEM analysis that a uniform distribution of surface-modified SNPs throughout the PTMSP membrane was achieved. The thermogravimetric analysis detected the thermal degradation of the modified PTMSP at 370 °C, which is comparable to neat PTMSP. The pervaporation measurements showed a maximum separation factor of 126 at 63 °C for 1.5 w/w% 1-butanol in the feed. The maximum total flux of approximately 1.74 mg·cm⁻²·min⁻¹ was observed with the highest inspected temperature of 63 °C and at the 1-butanol concentration in the feed 4.5 w/w%. The pervaporation transients showed that the addition of the surface-modified SNPs significantly enhanced the diffusivity of 1-butanol in the composite compared to the neat PTMSP membrane. This improvement was attributed to the influence of the well-dispersed SNPs in the PTMSP matrix, which introduced an additional path for diffusivity.
In this study, we proposed a novel and facile method to modify the surface of TiO2 nanoparticles and investigated the influence of the surface-modified TiO2 nanoparticles as an additive in a polyurethane (PU) coating. The hyperbranched polymers (HBP) were grafted on the surface of TiO2 nanoparticles via the thiol-yne click chemistry to reduce the aggregation of nanoparticles and increase the interaction between TiO2 and polymer matrices. The grafting of HBP on the TiO2 nanoparticles surface was investigated by means of X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Fourier transform infrared (FT-IR), nuclear magnetic resonance (NMR) and thermogravimetry analysis (TGA). The thermal and mechanical properties of nanocomposite coatings containing various amounts of TiO2 nanoparticles were measured by dynamic mechanical thermal (DMTA) and tensile strength measurement. Moreover, the surface structure and properties of the newly prepared nanocomposite coatings were examined. The experimental results demonstrate that the incorporation of the surface-modified TiO2 nanoparticles can improve the mechanical and thermal properties of nanocomposite coatings. The results also reveal that the surface modification of TiO2 with the HBP chains improves the nanoparticle dispersion, and the coating surface shows a lotus leaf-like microstructure. Thus, the functional nanocomposite coatings exhibit superhydrophobic properties, good photocatalytic depollution performance, and high stripping resistance.
This work aims to emphasize the effect of SiO2-Ag hybrid nanofillers on the thermal, mechanical and antibacterial properties of water-based acrylic coating. SiO2-Ag hybrid nanofillers were successfully synthesized and dispersed into water-based acrylic coating at the concentrations of 0.5-4 wt.%. The mechanical tests indicated that the incorporation of SiO2-Ag nanofillers into the water-based acrylic coating had slightly improved adhesion of the coating and had significantly enhanced its abrasion resistance and its thermal stability. The coating with 2 wt.% of the nanofillers had the highest values of adhesion (2.61 N/mm2), abrasion resistance (115.78 l/mil) and thermal stability (T5% = 340.14 oC). The antibacterial test against E.coli bacteria showed the antibacterial activity of SiO2-Ag nanofillers embedding in acrylic emulsion polymer matrix was comparable to that of AgNPs aqueous solution.
The beginning of nanomaterials and nanoscience dates back to 1959 when the Nobel laureate in Physics Richard Feynman gave the famous lecture entitled “There’s Plenty of Room at the Bottom [...]
In this work, unsaturated polyester resin matrix based polymer nanocomposites were fabricated incorporating sol-gel synthesized Fe 2 O 3 TiO 2 and co-precipitation synthesized NiFe 2 O 4 nanoparticles. The individual and synergic effect of nanoparticles on mechanical, electrical and optical properties in polymer matrix was evaluated. The maximum improvement in tensile strength (21.62%), Young's modulus (6.56%) and Vickers microhardness number was found in NiFe 2 O 4 loaded nanocomposite. Both the highest DC electrical conductivity and the lowest resistivity were found in (Fe 2 O 3 + TiO 2 + NiFe 2 O 4 ) nanoparticles dispersed nanocomposite. The maximum improvement in light absorbance (30.38%) in UV–Vis range was found in Fe 2 O 3 incorporated nanocomposite as well as the lowest (18.96%) optical energy band gap was found in NiFe 2 O 4 nanoparticles dispersed nanocomposite. These nanocomposites may find its potential use in industrial sectors as well as in light shielding applications.
Polymer nanocomposites have improved mechanical, optical and thermal properties compared to traditional thermoplastics. To study the impact of grafted brush–matrix interactions on the mechanical properties of nanoparticle filled polymers, uniaxial tensile testing with digital image correlation (DIC) was done on polystyrene (PS) grafted SiO2 in low molecular weight (MW) (N ∼ P), N = degree of polymerization of grafted brush, P = degree of polymerization of matrix, and high MW (2N = P) matrices at different loadings. The low matrix MW composites had higher strength than high MW composites at high loading but lower strength than the pure matrix. The high matrix MW composites had higher toughness at low loadings. SEM images of fracture surfaces revealed particle debonding and plastic void growth in the high toughness samples. The results show that the P/N ratio of polymer grafted nanoparticle composites is important for controlling the mechanical properties of polymer nanocomposites.
A robust generalized analytical expression for resonance frequencies of plasmonic nanoresonators, which consists of folded rectangular structures, is proposed based on a circuit route. The formulation is rigorously derived from the lumped circuit analogue of the plasmon resonance in a rectangular metallic nanorod. Induced by the nonhomogeneous charge distributions in the plasmonic resonators of rectangular end-caps, the electromagnetic forces drive the harmonic oscillations of free electrons in the plasmonic nanoresonators, generating intrinsically nonlinear shape-dependent LC resonance responses. Even for the plasmonic nanoresonators with much larger structure sizes than the skin depths, the significant frequency deviations due to the phase-retardation behavior can still be adequately described by the generalized expression. Moreover, for a large range of plasmonic nanoresonators with various folded rectangular geometries, sizes and materials, the generalized analytical expression gives the underlining physics and provides accurate predictions, which are perfectly verified by a series of numerical simulations. Our studies not only offer quantitative insights of nearly any plasmonic nanoresonators based on folded rectangular geometries, but also reveal potential applications to design complex plasmonic systems, such as periodic arrays with embedded rectangular nanoresonators.
Since the last decade, there has been an increasing demand for the design of more advanced functional materials. The integration of inorganic nanoparticles to polymer matrices is a powerful tool to confer their fascinating and complementary properties to the polymer materials. Among the different polymer nanocomposites, transparent nanocomposites are of particular interest due to their significance in a wide range of applications. To achieve a high level of transparency in the nanocomposites, it is necessary to minimize the aggregation of the nanoparticles that induce significant light scattering and thus hamper the application for transparent materials. The basic concepts of light scattering, the refractive index modulation and the methods to characterize the transparency of nanocomposites are provided to introduce this review. The fabrication of the transparent nanocomposites has been the subject of many efforts to develop methods to limit aggregation. To address this challenge, several methods have been implemented to control the polymerization process, the nanoparticle synthesis, and the polymer-nanoparticle interface together with the polymer casting or processing. The main methodologies developed to fabricate transparent nanocomposites are discussed according to four main categories: the blending of nanoparticles and polymer; the in-situ polymerization in the presence of pre-formed nanoparticles; the in-situ nanoparticle synthesis in a pre-formed polymer matrix; and finally the simultaneous polymerization and in-situ nanoparticle synthesis. The few studies dealing with casting of polymer solution loaded with core-shell nanoparticles are also discussed. In light of the literature on polymer nanocomposites, this review focuses on transparent nanocomposites with special attention given to the level of transparency and how this transparency is assessed for each study claiming transparency of the nanocomposite. For each class of nanocomposites, it is of great importance to provide an overview of the different level of transparency according to the thickness of the polymer material. The second part of the review provides a thorough overview of the properties investigated in transparent nanocomposites with attention paid to the characterization of transparency. The transparent nanocomposites were described according to the targeted properties which are primarily the improvement of mechanical properties, thermal stability, barrier properties, magnetic properties and the optical properties. The optical properties have been the most thoroughly investigated due to the myriad inorganic nanoparticles exhibiting an excellent wide range of optical properties. Thus, the present review also describes the polymer/nanoparticle systems designed for the fabrication of transparent polymer nanocomposites with advanced optical properties: UV or IR-filtering properties, photoluminescence, ability to produce extreme refractive index, dichroism or non-linear optical properties.
Hybrid nanomaterials based on inorganic nanoparticles and polymers are highly interesting structures since they combine synergistically the advantageous physical-chemical properties of both inorganic and polymeric components, providing superior functionality to the final material. These unique properties motivate the intensive study of these materials from a multidisciplinary view with the aim of finding novel applications in technological and biomedical fields. Choosing a specific synthetic methodology that allows for control over the surface composition and its architecture, enables not only the examination of the structure/property relationships, but, more importantly, the design of more efficient nanodevices for therapy and diagnosis in nanomedicine. The current review categorizes hybrid nanomaterials into three types of architectures: core-brush, hybrid nanogels, and core-shell. We focus on the analysis of the synthetic approaches that lead to the formation of each type of architecture. Furthermore, most recent advances in therapy and diagnosis applications and some inherent challenges of these materials are herein reviewed.
For the first time, organic tannic acid (TA) molecules and then inorganic praseodymium (Pr) cations as corrosion inhibitors were successfully loaded into a zeolitic imidazolate framework (ZIF8)-type porous coordination polymer (PCP) decorated on molybdenum disulfide, MoS2, (MS)-based transition metal dichalcogenides (TMDs) to create novel hybrid mesoporous Pr/TA-ZIF8@MS nanoreservoirs. Thereafter, the hybrid nanoreservoirs were embedded into the epoxy matrix for the preparation of smart pH-triggered nanocoatings. Characterizations of the Pr/TA-ZIF8@MS nanoreservoirs via Fourier transform infrared (FT-IR), X-ray diffraction (XRD), thermogravimetric (TG), Brunauer-Emmett-Teller (BET), and field emission-scanning electron microscopy (FE-SEM)/energy-dispersive X-ray spectroscopy (EDS) experiments confirmed the fabrication of mesoporous structures comprising Pr/TA interfacial interactions with ZIF8-decorated MS nanoplatelets possessing high thermal stability and compact/dense configuration features with a framework reorientation. A remarkable smart release of the inhibited cations (Pr3+ and Zn2+) in the presence of inbuilt TA at both acidic and alkaline media was achieved under inductively coupled plasma (ICP) examination. The superior pH-triggered self-healing inhibition through the smart controlled-release of Pr, tannate, Zn, and imidazole inhibited species/complexes from EP/Pr-TA-ZIF8@MS via ligand exchange was obtained from electrochemical impedance spectroscopy (EIS) assessments of the scratched coatings during 72 h of saline immersion. In addition, the long-term barrier-induced corrosion prevention (log |Z|10 mHz = 10.49 Ω·cm2 after 63 days) of the EP/Pr-TA-ZIF8@MS was actualized. Moreover, efficient increments of the coating cross-link density (56.45%), tensile strength (63.6%), and toughness value (56.5%) compared to the Neat epoxy coating revealed noticeable thermomechanical properties of the EP/Pr-TA-ZIF8@MS.
Standardized fractional-order capacitor (FOC) fabrication for application in the integrated circuit industry has always been hampered due to limitations inherent to the device. These limitations are due to the structure of the device, the nature of the dielectric, the range of the obtainable fractional order α and constant phase (CP) zone, lifetime, etc. Over the years, fabrication of single-component polymer nanocomposite-based FOCs has gained popularity. A common approach is not followed in the designs proposed to date. This chapter provides information about the aspects involved in fabrication of single-component FOCs which use polymer nanocomposite as dielectric. This includes describing various properties of most suitable polymers in FOC fabrication. Materials having prospects of being used as conductive fillers are indicated in this work. An account of the processing techniques used for composite synthesis is also provided. The process parameters affecting the final composite properties are described to guide the manufacturer at every step of FOC fabrication. Besides, this chapter gives an account of various FOC designs which may range from parallel plate configuration to capacitors fabricated on thin films. FOC properties have been related to design of the device, composition of the dielectric, etc. In addition, the chapter includes details about analysis and modeling techniques. As such, this chapter is aimed to be a guideline for polymer nanocomposite FOC fabrication.
The impact of surface functionalized titanium carbide (TiC) nanoparticles on the electrochemical and mechanical properties of epoxy nanocomposite was investigated. The functional TiC nanoparticles were synthesized using pyrrole (Py) and 2-amino-5-mercapto-1,3,4-thiadiazole (AMTD) and characterized by Transmission electron microscopy (TEM), X-ray diffraction (XRD), Field emission scanning electron microscopy (FE-SEM), and thermogravitric analysis (TGA) techniques. The resultant novel nanocomposite coating on Mg alloy in seawater was investigated by Tafel polarization, electrochemical impedance spectroscopy (EIS) and scanning electrochemical microscopy (SECM) studies. Electrochemical studies revealed excellent corrosion protection performance and a decreased corrosion current density for the EP-AMTD/TiC (Rc = 4861.25 kΩ.cm² and icorr = 3.75 μA/cm²) and the EP-Py/TiC nanocomposite coated Mg alloy (Rc = 3182.71 kΩ.cm² and icorr = 5.65 μA/cm²) in comparison with the plain epoxy coated Mg alloy (Rc = 244.67.25 kΩ.cm² and icorr = 9.55 μA/cm²) after 60 days of immersion. The results indicated that the functional TiC nanoparticles dispersed uniformly and retarded the propagation of aggressive ions to the coating/alloy interface. SECM observations confirmed the observation of least current at the scratched area of the EP-AMTD/TiC (2.1 I/nA) and the EP-Py/TiC (4.8 I/nA) coated alloy compared to pure epoxy coating (14.9 I/nA) even after 60 d immersion in seawater. SEM observations showed that reactive TiC nanofillers are dispersed uniformly. The changes in surface morphology, phase structure and composition were analyzed using SEM/EDX and XRD techniques. It was found that the intercalation of functional TiC nanoparticles in the epoxy coatings exhibited a smooth microstructure surface producing superior corrosion protection and mechanical properties. The mechanism of corrosion protection has been proposed.
This chapter reports several external factors affecting the electrical conductivity in polymeric composite and nanocomposite systems. Application of alternating electric field, magnetic field, temperature, positive temperature coefficient and negative temperature coefficient effects, filler properties, and other factors have been found to influence the electrical characteristics of the materials. Interaction forces between particles and external field may cause induced electric dipoles in composites. Moreover, dispersion, orientation, as well as agglomeration of filler or nanofiller may occur in the presence of external factors, thus influencing the electron mobility in materials. Nevertheless, the most promising and adequate external factor to enhance the filler alignment and electrical conductivity has yet not been identified.
Due to their reliability, availability, ease of fabrication, and low cost, polymers have been widely used as dielectric materials for electrical power equipment. Recently nanocomposites have been shown dramatic enhancements in polymer dielectrics and have been applied extensively in this field. Nanocomposites-based dielectrics are referred as nanodielectrics. Nanodielectrics have been developed for many applications, either indoor or outdoor, such as power cables, insulating spacers, energy storage devices, bushings, and suspension insulators. This chapter will describe in details the different applications of nanodielectrics with focusing on the obtained enhancements of nanodielectrics. For indoor applications, several properties of nanodielectrics are discussed including breakdown strength, permittivity, dielectric losses, space charge behavior, and partial discharge resistance. For outdoor applications, the investigated properties are erosion resistance, thermal conductivity, and hydrophobicity. Summary of the obtained results are presented and the mechanisms behind these results are discussed and highlighted.
Epoxy resins have highly appreciable design flexibility, good mechanical, thermal, chemical properties and also compatible with a wide variety of reinforcement materials. These excellent properties make epoxy resin as a choice resin for many high-performance engineering applications. Despite their high performances, there are challenges and opportunities to improve further the performance and durability of epoxy composites. This paper presents a survey of the literature on epoxy nanocomposites and the influences of nanofillers on the mechanical properties of epoxy composites. Herein, various pivotal parameters affecting their mechanical properties including their morphology are discussed. This review will have a great impact on the field and will assist researchers in enhancing the mechanical properties of epoxy polymer composites by reinforcing nanofillers.
For the first time, the UIO-66, NH2-UIO, and NH2-UIO particles covalently functionalized by Glycidyl Methacrylate (GMA@NH2-UIO), were utilized as the novel functional anti-corrosive fillers. The functionality, high surface area, phase composition, excellent thermal properties as well as chemical stability of the Zr-MOFs were proved by FT-IR, BET, XRD, TGA, and water stability tests, respectively. The smart pH-sensitive controlled-release activity of the corrosion inhibitors (i.e., Zr ions and organic compounds) from the prepared Zr-MOFs was proved by the water stability test of the Zr-MOFs particles in the acidic (pH = 2), neutral (pH = 7.5), and alkaline (pH = 12) solutions containing 3.5 wt% sodium chloride. The active inhibition properties of the Zr-MOFs were obtained in saline solution by two methods of (i) the solution phase and (ii) scratched epoxy coated samples containing Zr-MOFs by Tafel polarization method and EIS analysis. According to the EIS data, the excellent barrier (passive) properties of the composite film filled with GMA@NH2-UIO particles (G-UIN/EP) were proved by the highest impedance level at the lowest f (frequency) (log (|Z|10 mHz = 9.86 Ω.cm2), the lowest value of the breakpoint frequency (log (fb) = −1.42 Hz) and the highest coating undamaged index (85.93%) after 120 h of immersion. The salt spray (accelerated corrosion test) test (SST), pull-off (testing the strength of adhesion), and cathodic disbonding test (CDT) experiments showed excellent interfacial-adhesion properties of the G-UIN/EP sample in two dry (unexposed) and wet conditions. The hardness test showed that through the incorporation of the UIO, UIN, and G-UIN particles into the epoxy coating, the hardness, and scratch-resistance of the coating were notably improved.
For the first time, a novel metal-organic framework (MOF)-like nano-pigment was synthesized for fabrication of a high-performance epoxy composite material with excellent anti-corrosion and thermo-mechanical properties. The nanoceria-decorated cerium (III)-imidazole Network (NC/CIN) as a new metal-organic network (MON) structure was produced by a one-pot co-precipitation route through covalent and/or coordinate networking of cerium (III) as metallic cation centers and 2-methylimidazole as organic linker in methanol medium. The NC/CIN structure was analyzed by UV-Visible spectroscopy (UV-Vis), Furrier transform infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA), Raman spectroscopy, X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), field emission scanning electron microscopy (FE-SEM) and energy-dispersive X-ray spectroscopy (EDS) examinations. The characterization results revealed that the thermal-stable CIN hybrid product decorated by ceria nanocrystals (with average particle sizes below 51 nm) was produced via chemical bonding/networking of the * Corresponding author † Corresponding author Email addresses: ramezanzadeh@aut.ac.ir, ramezanzadeh-bh@icrc.ac.ir (B. Ramezanzadeh), m.motamedi@aut.ac.ir (M. Motamedi). 2 cerium and imidazole precursors, resulting in only 0.047 cm 3 g-1 pore free volume of the final networked product. Thermo-mechanical and anti-corrosion performance of the NC/CIN-incorporated epoxy composite were examined by tensile, dynamic mechanical thermal analysis (DMTA), electrochemical impedance spectroscopy (EIS) and salt spray evaluations. The results exhibited that the NC/CIN-contained epoxy composite provided remarkable barrier-inhibitive protection for mild steel in the corrosive environment (log |Z| 10 mHz = 9.91 Ω cm 2 after 7 weeks exposure of the intact coating to saline solution) as well as self-repairing protective properties in the artificial defected nanocomposite. Moreover, the great reinforcement in the cross-linking density (~40.8 mol cm-3 , more than 4 times efficiency), ductility and toughness (~246 J, 4 times efficiency) features of the epoxy composite was explored.
We investigate the reinforcing effects of both unmodified and surface modified nano titanium dioxide (TiO2) on the cure, mechanical, and thermal properties of natural rubber (NR) nanocomposites. The surface of nano TiO2 is modified by cationic surfactants cetyltrimethylammonium bromide (CTAB) and tetraethylammonium bromide (TEAB). The surface modification of nano TiO2 is characterized by Fourier transform infrared (FTIR) spectra and Field emission scanning electron microscopy (FESEM). The result reveals that surface modified nano TiO2 is much more efficient in improving the resulting properties of NR nanocomposites in comparison with unmodified nano TiO2. The excellent improvement in the properties of surface modified nano TiO2/NR composites is due to the better hydrophobicity and uniform dispersion of modified nano TiO2 within the NR matrix, as confirmed from morphological analysis. CTAB is much more effective than TEAB with respect to the properties of nano TiO2 based NR composites.
Motivated by the impact of electromagnetic radiation on electronic gadgets and living beings, herein we developed a light weight flexible EMI shielding material to meet the demands of consistently developing technology. In the present study, we utilized the concept of preferential distribution and double percolation to fabricate a conductive polymer composite that absorbs EM radiation. We employed EMA/EOC (50/50) wt% binary blend as the polymer matrix and MWCNT as the functional filler. With the addition of 3 wt% MWCNT, the composite demonstrated a shielding efficiency of −18.66 dB and with 15 wt% MWCNT, a total shielding efficiency of −34.06 dB was attained combined with good mechanical and thermal properties. We believe this work provides an insight in developing a scalable and affordable EMI shield finding its potential in both academic and industrial application.
Polyaniline (PANI) has recently received sustained attention due to its outstanding electrical properties, good
chemical and environmental stability, simple preparation process, and extensive application in numerous fields
such as chemical sensor, corrosion devices, photovoltaic cell, gas separation membranes, etc. However, the main
drawback of PANI is poor solubility caused by the rigid backbone. Interestingly, the chemically modified PANI
not only shows improved processability, but exhibits better conductive and anticorrosion properties than pure
PANI. This review mainly highlights the developments in chemical modifications of PANI with enhanced
properties over the last decades, which would be helpful for guiding the rational design of PANI in structure and
property in order to further cater the practical demands.
Filler materials are widely used in combination with polymer materials. Conventional filler particles generally cause light scattering and absorption because of their optical characteristic or refractive index difference. With nanoparticles (NPs) as a filler material, it is theoretically possible to manufacture transparent compounds due to their small particle dimensions reducing the interaction with light. Nevertheless, the particles tend to build agglomerates and aggregates which reduce the composite’s transparency considerably. This review gives an overview of the effect different particle materials have on the properties of transparent polymer composites with consideration of the composite’s transparency. There are very few reports on highly transparent and thick (>1 mm) polymer nanocomposites with such an amount of particles that affect other properties of the polymer significantly. In the majority of cases, NPs lead to a significant lower transparency. This indicates that the homogeneous dispersion of the particles is still a major difficulty in producing transparent nanocomposites with enhanced properties.
The optical properties of metal nanoparticles, particularly their localized surface plasmon effects, are well established. These plasmonic nanoparticles can respond to their surroundings or even influence the optical processes (for example, absorption, fluorescence and Raman scattering) of molecules located at their surface. As a result, plasmonic nanoparticles have been developed for multiple purposes, ranging from the detection of chemicals and biological molecules to light-harvesting enhancement in solar cells. By dispersing the nanoparticles in polymers and creating a hybrid material, the robustness, responsiveness and flexibility of the system are enhanced while preserving the intrinsic properties of the nanoparticles. In this Review, we discuss the fabrication and applications of plasmonic polymer nanocomposites, focusing on applications in optical data storage, sensing and imaging and photothermal gels for in vivo therapy. Within the nanocomposites, the nanoporosity of the matrix, the overall mechanical stability and the dispersion of the nanoparticles are important parameters for achieving the best performance. In the future, translation of these materials into commercial products rests on the ability to scale up the production of plasmonic polymer nanocomposites with tailored optical features.
Research pertaining to conductive polymers has gained significant traction in recent years, and their applications range from optoelectronics to material science. For all intents and purposes, conductive polymers can be described as Nobel Prize-winning materials, given that their discoverers were awarded the Nobel Prize in Chemistry in 2000. In this review, we seek to describe the chemical forms and functionalities of the main types of conductive polymers, as well as their synthesis methods. We also present an in-depth analysis of composite conductive polymers that contain various nanomaterials such as graphene, fullerene, carbon nanotubes, and paramagnetic metal ions. Natural polymers such as collagen, chitosan, fibroin, and hydrogel that are structurally modified for them to be conductive are also briefly touched upon. Finally, we expound on the plethora of biomedical applications that harbor the potential to be revolutionized by conductive polymers, with a particular focus on tissue engineering, regenerative medicine, and biosensors.
Micro-nanofibrillated cellulose (MFC/NFC) and graphene-based composites are interesting materials due to their complementary functional properties, opening up potential in a variety of applications. Graphene, graphene oxide (GO) and reduced graphene oxide (RGO) were used in this comparative study as reinforcement functional fillers for the fabrication of multifunctional MFC nanocomposites using a simple aqueous dispersion based mixing method. The MFC composites showed different properties depending on the type of filler used. Graphene was seen to agglomerate and was poorly dispersed in the MFC matrix, whilst GO and RGO were homogeneously dispersed due to the presence of functional groups that promoted a strong interfacial molecular interaction between the filler and the MFC matrix. At 0.6 wt% filler loading, the tensile strength for MFC/GO and MFC/RGO increased by 17 % and 22 %, respectively, whilst the Young's modulus increased from 18 GPa to 21 GPa and 25 GPa, respectively. Compared to the neat MFC, addition of 5 wt% of graphene enhanced the thermal stability by 5 % and whilst with the addition of GO and RGO stability increased by 2 and 3 %, respectively. Graphene/MFC and RGO/MFC showed a high electrical conductivity of 1.7 S m⁻¹ and 0.5 S m⁻¹, respectively while the GO reinforced composites were insulators.
Plasmonic nanostructures are extensively used building blocks for engineering optical materials and device architectures. Plasmonic nanocomposites (pNCs) are an emerging class of materials that integrate these nanostructures into hierarchical and often multifunctional systems. These pNCs can be highly customizable by modifying both the plasmonic and matrix components, as well as by controlling the nano- to macroscale morphology of the composite as a whole. Assembly at the nanoscale plays a particularly important role in the design of pNCs that exhibit complex or responsive optical function. Due to their scalability and tunability, pNCs provide a versatile platform for engineering new plasmonic materials and for facile integration into optoelectronic device architectures. This review provides a comprehensive survey of recent achievements in pNC structure, design, fabrication, and optical function, along with some examples of their application in optoelectronics and sensing.
Surface topography and phase-manipulated distribution of hybrid UV curable coatings is performed. Accordingly, phase separation is controlled by changing the inorganic/organic ratio and the photoinitiator content as these are the main thermodynamic and kinetic affecting factors, respectively. Chemical and mechanical evolution of the samples during photopolymerization is investigated by time-resolved Fourier transform infrared spectroscopy and photorheometry, respectively. It is found that the samples that contain larger portion of inorganic oligomers are polymerized faster, but undergo gelation later; this provides them more time to undergo phase separation prior to gelation. Therefore, their surfaces become rougher and more heterogeneous, which is confirmed by atomic force microscopey. Furthermore, adding larger amounts of photoinitiator into the samples leads to them being photopolymerized faster and undergo gelation at lower conversion. So, they have less time and thermodynamic tendency to undergo phase separation prior to gelation; their surfaces thus become smoother and more homogeneous.
Polymer-grafted nanoparticles are an important component of many classes of polymer nanocomposites. Here, we review the structure of polymer brushes on spherical nanoparticle surfaces and discuss how that structure influences the properties of polymer grafted nanoparticles (PGNP). We focus on the various structural relationships of polymer grafted nanoparticles and the several conformational regimes that emerge in grafted systems. Finally, we detail several specific applications of PGNP either in polymer nanocomposites or single particle systems, focusing on how the brush structure in particular enables the various applications. Due to the inherently interdisciplinary nature of the polymer nanocomposite field, such applications range from those in biological science to materials engineering, lubrication, and topics in separations.
A metal-organic-framework (MOF) based on zeolitic imidazole framework (ZIF-8) is utilized as a modifier to lower the dielectric constant and improve the mechanical properties of an epoxy matrix. The imidazole group on the surface of the ZIF-8 initiates epoxy curing, resulting in covalent bonding between the ZIF-8 crystals and epoxy matrix. A substantial reduction in dielectric constant and increase in tensile modulus were observed. The implication of the present study for utilization of metal-organic-framework (MOF) to improve physical and mechanical properties of polymeric matrices is discussed.
Graphene nanoplatelets (GNP) were exfoliated using a nondestructive chemical reduction method and subsequently decorated with polymers using two different approaches: grafting from and grafting to. Poly(methyl methacrylate) (PMMA) with varying molecular weights was covalently attached to the GNP layers using both methods. The grafting ratios were higher (44.6% to 126.5%) for the grafting from approach compared to the grafting to approach (12.6% to 20.3%). The products were characterized using thermogravimetric analysis–mass spectrometry (TGA-MS), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), atomic force microscopy (AFM), and transmission electron microscopy (TEM). The grafting from products showed an increase in the grafting ratio and dispersibility in acetone with increasing monomer supply; on the other hand, due to steric effects, the grafting to products showed lower absolute grafting ratios and a decreasing trend with increasing polymer molecular weight. The excellent dispersibility of the grafting from functionalized graphene, 900 μg/mL in acetone, indicates an increased compatibility with the solvent and the potential to increase graphene reinforcement performance in nanocomposite applications.
Nanocomposites were synthesized by dispersing multiwalled carbon nanotube (MWCNT) of different weight percentages (0.4, 0.6 and 1.0 wt%) into epoxy resin polymer matrix. Prior to the MWCNTs were functionalized by a mixed acid chemical treatment. The composites were characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction. The morphology of the composites was studied by field emission scanning microscope (FESEM). The tensile strength and modulus of elasticity of epoxy were substantially improved due to well dispersion of f-MWCNT in epoxy polymer and firm interfacial adhesion between epoxy and MWCNTs.
Polymer matrix nano-composites are gaining popularity day by day because of the significant enhancement in mechanical, dynamic and thermal properties over conventional materials. This research work is concentrated on the Development and Analysis of Epoxy/nano SiO2 Polymer Matrix Composite. The PMC material was fabricated by adding various weight percent of nano SiO2 in epoxy matrix which varies from 0 wt% to 3wt% and were dispersed with the help of ultrasonication and later on the mechanical properties like tensile strength, impact strength were analyzed. Microstructural Study was also done which assisted in conclusions of result pattern. Mechanical properties showed an increasing trend on adding a high wt% loading of nano silica particles.
This study reports the fabrication of hybrid nanocomposites based on silver nanowire/manganese dioxide nanowire/poly(methyl methacrylate) (AgNW/MnO2NW/PMMA), using solution casting technique, with outstanding dielectric permittivity and low dielectric loss. AgNW was synthesized using the hard-template technique, and MnO2NW was synthesized employing a hydrothermal method. The prepared AgNW:MnO2NW (2.0:1.0vol%) hybrid nanocomposite showed a high dielectric permittivity (64 at 8.2 GHz) and low dielectric loss (0.31 at 8.2 GHz), which are among the best reported values in the literature in the X-band frequency range (8.2-12.4 GHz). The superior dielectric properties of the hybrid nanocomposites were attributed to: (i) dimensionality match between the nanofillers, which increased their synergy, (ii) better dispersion state of AgNW in the presence of MnO2NW, (iii) positioning of ferroelectric MnO2NW in between AgNWs, which increased the dielectric permittivity of nanodielectrics, thereby increasing dielectric permittivity of the hybrid nanocomposites, (iv) barrier role of MnO2NW, i.e. cutting off the contact spots of AgNWs and leading to lower dielectric loss, and (v) AgNW aligned structure, which increased the effective surface area of AgNWs, as nanoelectrodes. Comparison of the dielectric properties of the developed hybrid nanocomposites with the literature highlights their great potential for flexible capacitors.
The field of polymer nanocomposites has been at the forefront of research in the polymer community for the past few decades. Foundational work published in Macromolecules during this time has emphasized the physics and chemistry of the inclusion of nanofillers; remarkable early developments suggested that these materials would create a revolution in the plastics industry. After 25 years of innovative and groundbreaking research, PNCs have enabled many niche solutions. To complement the extensive literature currently available, we focus this Perspective on four case studies of PNCs applications: (i) filled rubbers, (ii) continuous fiber reinforced thermoset composites, (iii) membranes for gas separations, and (iv) dielectrics for capacitors and insulation. After presenting synthetic developments we discuss the application of polymer nanocomposites to each of these topic areas; successes will be noted, and we will finish each section by highlighting the various technological bottlenecks that need to be overcome to take these materials to full-scale practical application. By considering past successes and failures, we will emphasize the critical fundamental science needed to further expand the practical relevance of these materials.