Polymer nanocomposites with enhanced performances are becoming a trend in the current research field, overcoming the limitations of bulk polymer and meeting the demands of market and society in ...tribological applications. Polytetrafluoroethylene, poly(ether ether ketone) and ultrahigh molecular weight polyethylene are the most popular polymers in recent research on tribology. Current work comprehensively reviews recent advancements of polymer nanocomposites in tribology. The influence of different types of nanofiller, such as carbon-based nanofiller, silicon-based nanofiller, metal oxide nanofiller and hybrid nanofiller, on the tribological performance of thermoplastic and thermoset nanocomposites is discussed. Since the tribological properties of polymer nanocomposites are not intrinsic but are dependent on sliding conditions, direct comparison between different types of nanofiller or the same nanofiller of different morphologies and structures is not feasible. Friction and wear rate are normalized to indicate relative improvement by different fillers. Emphasis is given to the effect of nanofiller content and surface modification of nanofillers on friction, wear resistance, wear mechanism and transfer film formation of its nanocomposites. Limitations from the previous works are addressed and future research on tribology of polymer nanocomposites is proposed.
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•Cd0.9Mg0.1S filled PVA/CMC blend was prepared by thermolysis and casting techniques.•X-ray diffraction and Fourier transform infrared have been performed.•The optical and dielectric ...properties of the polymeric blend have been explored.•The energy bandgap has been tuned from 5.40 eV to 5.02 eV via doping process.•CdS/Mg filled PVA/CMC blend films are recommended for optoelectronic applications.
In this work, the role of Cd0.9Mg0.1S (CdS/Mg) nanofillers on the structural, optical, and dielectric properties of polyvinyl alcohol/carboxymethyl cellulose (PVA/CMC) blend has been explored. CdS/Mg nanoparticles filled PVA/CMC blend was prepared using thermolysis and casting techniques. The formation of a single phase Cd0.9Mg0.1S and the insertion of the nano powder inside the blend matrix were examined by X-ray diffraction (XRD) and Fourier transform infrared (FTIR). The morphology of the samples and confirmation of the homogeneity of the formed blends were probed utilizing scanning electron microscope (SEM) and energy dispersive spectrometry (EDS). Doping amount effect on the absorbance, transmittance spectra, optical band gap and the refractive index was investigated using UV–vis spectroscopy technique. The resulting changes in the different optical parameters such as the average oscillator strength, the single oscillator energy, the dispersion energy, the residual dielectric constant were also explored. The complex impedance technique was employed to trace the influence of doping on the real and imaginary dielectric parts as a function of frequency was examined. The modified properties nominate CdS/Mg filled PVA/CMC blend films for optoelectronic applications.
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The presence of emerging organic micropollutants (OMPs) in drinking and potable waters is a matter of great concern due to the health hazards associated with these. In this work, we ...present the preparation and application of a thin-film nanocomposite (TFN) membrane containing functionalized graphene oxide to effectively remove low-molecular-weight OMPs from water. Graphene oxide was functionalized with amino silane to enhance its cross-linking capability during the formation of the polyamide active layer via interfacial polymerization of diethylene triamine and trimesoyl chloride. The TEM analysis showed that amino silane functionalized GO had 2–3 layered sheets, while non-functionalized graphene oxide appeared multilayered or stacked. XPS analysis confirmed the successful functionalization of GO. Characterization of the membranes with advanced techniques confirmed the successful incorporation of the GO and its functionalization: spectra from Fourier Transform Infra Red spectroscopy had the characteristic peaks of GO and NH groups; scanning Electron Microscopy (SEM) images showed a continuous presence of GO nanosheets. Contact angle measurements showed the TFN membranes to be more hydrophilic than their thin film composite (TFC) counterparts. Incorporating functionalized oxide nanosheets in the active polyamide layer produced additional water permeation channels, resulting in an improvement of ∼25 % in permeate flux compared to the pristine TFC and the TFN membrane with non-functionalized GO. The removal efficiencies of four OMPs commonly found in natural waters: Amitriptylene HCl (ATT HCl) and Bisphenol-A (BPA), Acetaminophen (ACT), and Caffeine (CFN) were determined for the synthesized membranes. The TFN membrane with functionalized GO outperformed its TFC counterpart with ∼100 % removal for BPA, ∼ 90 % for CFN and ATT HCl, and ∼80 % removal for the low molecular weight ACT. The high-efficiency rejection of OMPs was attributed to the synergistic effects of size exclusion as well as the reduced specific interactions between the functional groups.
A REVIEW OF EPOXY-NANOCOMPOSITE PROPERTIES Abbas, Samer Saad; Raouf, Raouf Mahmood; Al-Moameri, Harith
Journal of engineering and sustainable development (Online),
01/2024, Letnik:
28, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Epoxy resins have been the subject of many studies as a consequence of their extensive usage in recent years. The brittleness and low resistance to propagation and crack initiation of epoxy resins ...are well-recognized characteristics. Therefore, in recent years, experts have concentrated on increasing epoxy resin's fracture resistance. Adding inorganic nanoparticles like titanium dioxide (TiO2) TiO2, silica (SiO2), carbon black, alumina (Al2O3), and others to the polymer matrix is one of the most investigated techniques in polymer science. Despite having a modest nanofiller content, the resulting nanocomposites may enhance their thermal, mechanical, rheological, electrical, and optical characteristics. These nanocomposites are an alternative to metal-based materials. They have great promise as multifunctional materials in a range of applications, including optoelectronic devices, semiconductor devices, civil engineering, automotive, and aerospace. To show potential future directions and market prospects for polymer nanocomposites reinforced with TiO2 nanoparticles, current results, and trends have been examined and highlighted. In addition, the current review surveys many studies that highlighted using nanoparticles as reinforcement, their different structure, the interface, and the geometry and structure of the resulting nano-materials reinforced resin.
The widespread applications of polymeric materials require the use of conventional flame retardants based on halogen and phosphorous compounds to satisfy fire safety regulatory standards. However, ...these compounds, particularly halogen-based examples, are persistent organic pollutants of global concern and generate corrosive/toxic combustion products. To account for eco-friendliness, ultimate mechanical/physical properties and processing difficulties, the window of options has become too narrow. Although the incorporation of non-toxic nanofillers in polymers shows positive potential towards flame retardancy, many obstacles remain. Moreover, most of the literature on these materials is qualitative, and often points to conflicting/misleading suggestions from the perspectives of short-term and long-term fire exposure tests. Hence, there is a renewed need to fundamentally understand the fire response of such materials, and complement experimental results with theoretical modelling and/or numerical simulation.
A part of this review will highlight the ecological impacts of using conventional flame retardants, thereby signifying the necessity to use eco-friendly agents. In other sections, we explore the use of various nanofillers for this purpose, compare their performance with traditional systems, provide insights into different testing standards and combustion mechanisms, modelling aspects of the combustion behavior, and identify novel approaches that could be considered for meeting the fire safety standards with eco-friendly materials.
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 °C). 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.
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•SiO2–Ag nanohybrids were successfully synthesized.•SiO2–Ag nanofillers were relatively well dispersed into the acrylic polymer matrix.•SiO2–Ag nanofillers enhanced significantly the mechanical properties of coating.•The nanocomposte containing 2 wt% SiO2–Ag nanofillers has high thermal stability.•The nanocomposite coating has good antibacterial activity.
The paper combines and reviews the experimental studies on performance of various potential nanofillers elements incorporated in the epoxy polymer resin that are used as protective coating for metal ...substrate. The epoxy composite formed by dispersing the nano sized secondary elements namely silica oxide, aluminum oxide, titanium oxide, cerium oxide, graphite oxide and nano clay in the epoxy matrix are studied in the perspective of corrosion resistance, adhesion strength and dispersion properties. The paper encompasses the study on epoxy nanocomposite with single element reinforcement particles and also the hybrid of two different elements that are used as reinforcement fillers. The discussion witness’s various corrosive protection assessing techniques such as electrochemical studies, pull of adhesion test, salt spray test and their results are studied and analyzed in the prospect of overviewing the performance of nanofillers in epoxy matrix.
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•Development of nanofillers based on the composition and structure evolution is summarized.•Selection criteria of nanofillers for fabricating TFN membranes is highlighted.•Application ...of TFN membranes for gas and liquid separations during the last 5 years is outlined.•Current challenges and further prospects of TFN membranes are discussed.
Thin film nanocomposite (TFN) membranes, comprising nanofillers and nanoscale dense polymeric barriers, were prepared by introducing nanomaterials into a polyamide layer during interfacial polymerization for diverse separations. The versatile nanofillers allow the TFN membranes to go beyond the longstanding trade-off limitation and alleviate the fouling propensity by tailoring the membrane surface properties, i.e., pore characteristics, hydrophilicity, charge, and compactness, even when applied in low dose. The enhanced performance is primarily determined by the composition and structure of the nanofillers. Therefore, in this review, particular attention is paid to the compositional and structural evolution of nanofillers. Starting from the functionality, some emerging and prevalent nanofillers are emphatically introduced, followed by discussing their selection criteria for targeted separation. Furthermore, the encouraging applications of TFN membrane in the past 5 years for gas separation, nanofiltration (in water and organic solvents), reverse osmosis, forward osmosis, and pervaporation are outlined. Moreover, current challenges and further prospects of fabricating TFN membranes are proposed. Through this critical review, a fundamental guide of designing unique nanofillers with specific composition and structure for advanced TFN membrane separation technologies is provided.
Proton exchange membrane fuel cells (PEMFCs) exhibit increasing potential in a variety of applications, from automotive to stationary power generation, due to their superior advantages such as high ...efficiency, quick start-up and low emissions. The cell performance and operation life of PEMFCs are directly affected by the proton exchange membranes (PEMs). Nafion, a well-known perfluorosulfonic acid polymer, represents the state of the art of PEMs. To further improve the performance of Nafion, various nanofillers are incorporated into Nafion matrices, leading to the formation of composite PEMs with enhanced proton conductivity, mechanical strength and chemical stability. This review summarizes the recent advancements in Nafion composite PEMs based on four typical kinds of nanofillers: framework nanomaterials, carbon nanomaterials, polyoxometalate nanoclusters, and inorganic oxide nanoparticles. The preparation strategy, structure-property relationship and fuel cell applications of these membranes are discussed comprehensively, particularly focusing on the synergistic effect between Nafion and nanofillers. This review can provide an instructive insight for designing high-performance PEMs towards emerging energy technologies.
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•Latest advancements in Nafion composite PEMs are introduced.•Typical nanofillers used for Nafion modification are summarized.•Nafion composite PEMs exhibit enhanced fuel cell performance.
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