Showing papers in "Composite Interfaces in 2014"
TL;DR: In this article, a layered aligned dispersion of graphene in polyvinyl alcohol (PVA) nanocomposites is prepared in the form of films through simple solution processing route.
Abstract: Layered aligned dispersion of graphene in graphene/polyvinyl alcohol (PVA) nanocomposites is prepared in the form of films through simple solution processing route. The results indicate that there exist an interfacial interaction between PVA and graphene because of hydrogen bonding. This is responsible for the change in structure of PVA (such as decrease in the level of crystallization) and exhibiting ductile PVA nanocomposite film with improved tensile modulus, tensile strength, and thermal stability. Moreover, to improve the mechanical properties of PVA nanocomposites, graphene is successfully modified using a non-covalent modifier, sodium alginate (SA) and there exist an ‘anion-π’ type of interaction in between SA and graphene. The modification results in finer dispersion of the graphene in PVA/SA-m-graphene nanocomposites. In addition, there exist a hydrogen bonding in between PVA and SA. This has resulted in the remarkable improvement in mechanical properties of PVA/SA-m-graphene nanocomposites as co...
62 citations
TL;DR: Fiber metal laminates (FMLs) as mentioned in this paper are the hybrid Laminates consisting of alternating thin layers of metal sheets and fiber-reinforced composite material. Interface between metal and polymer layer plays...
Abstract: Fiber metal laminates (FMLs) are the hybrid laminates consisting of alternating thin layers of metal sheets and fiber-reinforced composite material. Interface between metal and polymer layer plays ...
45 citations
TL;DR: In this paper, the chemical structure of the styrene-butadiene-glycidyl methacrylate terpolymer (GMA-SBR) was analyzed using infrared spectroscopy, 1H NMR, gel permeation chromatography, and differential scanning calorimetry.
Abstract: Styrene-butadiene-glycidyl methacrylate terpolymer (GMA-SBR) was synthesized by emulsion polymerization for the fuel efficient tire tread composite. The chemical structure of the GMA-SBR was analyzed using infrared spectroscopy, 1H NMR, gel permeation chromatography, and differential scanning calorimetry. The GMA-SBR/silica composite is the first instance introduced covalent bonds between silica filler and rubber molecules by in-chain modification of styrene-butadiene molecules. After compounding, the curing characteristics, the mechanical and dynamic mechanical properties of the composites were analyzed. The GMA-SBR/silica composite exhibited higher wear resistance of 32.9% and lower rolling resistance of 25.7% than the styrene-butadiene rubber 1721/silica composite. These results are due to the improvement of silica dispersion in the composite as the covalent bonding increased the filler–rubber interaction and the countervailing effects of less filler flocculation. The proposed approach assists in findi...
39 citations
TL;DR: In this article, halloysite nanoclay was subjected to sulfuric acid treatment and used as a reinforcing agent in polyvinyl alcohol (PVA), which is one of the natural substances that is currently...
Abstract: In this study, halloysite nanoclay was subjected to sulfuric acid treatment and used as a reinforcing agent in polyvinyl alcohol (PVA). Halloysite is one of the natural substances that is currently...
36 citations
TL;DR: In this article, a randomly distributed multi-particle model considering the effects of particle/matrix interface and strengthening mechanisms introduced by the particles has been constructed, where the particle shape, distribution, volume fraction and the particles' interfaces due to the factors including element diffusion were considered.
Abstract: A randomly distributed multi-particle model considering the effects of particle/matrix interface and strengthening mechanisms introduced by the particles has been constructed. Particle shape, distribution, volume fraction and the particles/matrix interface due to the factors including element diffusion were considered in the model. The effects of strengthening mechanisms, caused by the introduction of particles on the mechanical properties of the composites, including grain refinement strengthening, dislocation strengthening and Orowan strengthening, are incorporated. In the model, the particles are assumed to have spheroidal shape, with uniform distribution of the centre, long axis length and inclination angle. The axis ratio follows a right half-normal distribution. Using Monte Carlo method, the location and shape parameters of the spheroids are randomly selected. The particle volume fraction is calculated using the area ratio of the spheroids. Then, the effects of particle/matrix interface and strength...
25 citations
TL;DR: In this paper, the authors focus on crosslinking epoxidised natural rubber by dicarboxylic acids which react with the epoxy sites along the chain.
Abstract: The work focuses on crosslinking epoxidised natural rubber by dicarboxylic acids which react with the epoxy sites along the chain. The crosslinking reaction at 180 °C is followed in a rheometer, and the cured materials are characterised by stress–strain experiments. The cure process is tremendously accelerated (from 3 h to 20 min) in the presence of an equimolar amount of 1,2-dimethylimidazole. Thermal stability and fatigue life experiments were carried out on samples charged with carbon black and antioxidants. The results are found in between the ones obtained with standard sulphur or peroxide crosslinked samples.
25 citations
TL;DR: Polyhydroxyalkanoates (PHAs) are polyesters of hydroxyacids naturally synthesized in bacteria as a carbon reserves as discussed by the authors, and Bacillus subtilis can synthesize and accumulate PHA as carbon source under limiti...
Abstract: Polyhydroxyalkanoates (PHAs) are polyesters of hydroxyacids naturally synthesized in bacteria as a carbon reserves. Bacillus subtilis can synthesize and accumulate PHA as carbon source under limiti...
21 citations
TL;DR: In this article, the microbond test of carbon fiber-reinforced polyphenylene sulfide (PPS) composites was used to evaluate the performance of interfacial micromechanical performance.
Abstract: Interfacial micromechanical performance of carbon fiber (CF)-reinforced polyphenylene sulfide (PPS) composites was studied by the microbond test, which has been well accepted as the most important ...
21 citations
TL;DR: In this paper, the ability of DCP to improve adhesion between polylactide (PLA) and flax or hemp fibres by their interphase cross-linking was assessed.
Abstract: Dicumyl peroxide (DCP) is commonly applied as a cross-linking agent in polymer processing. The main aim of this work was to assess the ability of DCP to improve adhesion between polylactide (PLA) and flax or hemp fibres by their interphase cross-linking. Short fibre-reinforced PLA composites were manufactured due to the importance of short fibres in injection moulding of high-quality biocomposites. Reactive extrusion of the PLA, flax or hemp fibres, and DCP was performed. The flax or hemp fibre content was 10 wt%, while DCP varied with 0.5 and 2.5 wt%. The fibres and PLA were mechanically mixed, extruded, granulated and injection moulded to form samples for testing. The samples were characterized by differential scanning calorimetry (DSC), tensile and impact strength tests, dynamic mechanical analysis and scanning electron microscopy (SEM). It was found that flax and hemp fibres increased the Young’s modulus while these fibres decreased the impact strength. Addition of DCP led to increase in PLA crystalli...
19 citations
TL;DR: In this paper, the authors aimed to improve the strength of textile composites by applying surface treatments on natural fibers, such as flax and hemp, and the matrix was an epoxy acrylate.
Abstract: In this study, we aimed to improve the strength of textile composites by applying surface treatments on natural fibers. Natural fibers used were flax and hemp, and the matrix was an epoxy acrylate ...
19 citations
TL;DR: In this paper, Zinc-incorporated porous TiO2 coatings (Zn-TiO2) were prepared on Ti substrate by micro-arc oxidation (MAO) technique in the zinc gluconate-containing electrolyte.
Abstract: Titanium (Ti) and its alloys are widely used as metallic biomaterials for fabrication of dental and orthopedic implants due to their favorable biocompatibility and corrosion resistance in a body environment. However, the thin oxide layer (TiO2) on Ti substrate formed naturally in air or in many aqueous environments is bioinert and surrounded by fibrous tissues without producing any chemical or biological bond to bone when implanted. In the present work, Zinc-incorporated porous TiO2 coatings (Zn–TiO2) were prepared on Ti substrate by micro-arc oxidation (MAO) technique in the zinc gluconate-containing electrolyte. The surface morphology, cross-sectional morphology, composition, and phase of the coatings were analyzed using scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffractometry, respectively. Surface topography and roughness of the coatings were investigated by atomic force microscopy operated in tapping mode. The results showed that Zn was successfully incorporated into the...
TL;DR: In this paper, an analytical model for chitosan nanocomposites reinforced by needle-like hydroxyapatite (HA) and globule-like polyhedral oligomeric silsesquioxane (POSS) particles is presented.
Abstract: Analytical models have been evaluated for chitosan nanocomposites reinforced by needle-like hydroxyapatite (HA) and globule-like polyhedral oligomeric silsesquioxane (POSS) particles. The particle elastic stress distribution was investigated for the case of high loads with the matrix deforming plastically and the particle pull-out energy during matrix crack propagation was modelled. Model predictions, over a range of reasonable interfacial shear stress values and particle aspect ratios, show contrasting behaviour between the two types of nanoreinforcement. In HA particles, the axial stress is distributed fairly uniformly, whereas, with POSS it is concentrated towards the centre of the particle. The radial stress at the HA particle surface was found to be uniformly distributed, whereas in POSS it increased non-linearly to a high (theoretically infinite) value with distance from the particle centre to the end. For particles bridging a travelling matrix crack, the model predicts that the pull-out energy dens...
TL;DR: In this article, the surface modification of beech wood layers was first carried out by rinsing them in distilled water, followed by surface activation with nickel metallic as a catalyst that is prepared on beechwood surface by reduction of Ni+2 ions using as a reduction agent at pH 11.95 A and the results indicate that the nickel crystallites grow rapidly with increasing number of deposition run.
Abstract: Surface modification of beech wood layers was first carried out by rinsing them in distilled water, followed by surface activation with nickel metallic as a catalyst that is prepared on beech wood surface by reduction of Ni+2 ions using as a reduction agent at pH 11. Finally, the nickel was deposited by electroless nickel coating in many baths separated by drying at 100 °C during 24 h. Both texture and structural properties of nickel deposited on beech wood were characterized using both scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. The SEM results show that the nickel film thickness prepared on beech wood surface after four baths is within 2.9–3 μm. The XRD patterns revelated that nickel deposited on beech wood has crystallite size between 83.37 and 149.95 A and the results indicate that the nickel crystallites grow rapidly with increasing number of deposition run.
TL;DR: The currently developed composite materials possess good biocompatibility and allow the growth and osteogenic differentiation of hMSCs in vitro, suggesting their potential application in stem cell-based bone engineering.
Abstract: Bone tissue engineering offers the prospect of alternative therapies for clinically relevant skeletal defects. Poly(butylene succinate) (PBSu) is a biodegradable and biocompatible polyester which possesses some unfavorable biomaterial properties. In order to improve this limitation, we developed PBSu/hydroxyapatite (HA) and PBSu/β-tricalcium phosphate (TCP) composites to support the growth and osteogenic differentiation of human mesenchymal stem cells (hMSCs). The results showed that phase separation morphology of the composites were detected in both PBSu/HA and PBSu/TCP films where calcium phosphate (HA and TCP) dispersed thoroughly into PBSu. The addition of either HA or TCP increased the hydrophilicity of the resulting composites. All the materials appeared to be biocompatible and supported in vitro growth and osteoblast differentiation of hMSCs. In conclusion, the currently developed composite materials possess good biocompatibility and allow the growth and osteogenic differentiation of hMSCs in vitro...
TL;DR: In this paper, the removal of metal contaminants from aqueous solutions has been a cause of major concern and the water is polluted by human activities; it perturbs water for agriculture and aquatic life.
Abstract: Removal of metal contaminants from aqueous solutions has been a cause of major concern. The water is polluted by human activities; it perturbs water for agriculture and aquatic life. For this purpo...
TL;DR: In this paper, the physical, chemical, and surface properties of untreated and chemically modified fibers were studied using X-ray diffraction (wide angle Xray scattering), Fourier transform infrared spectroscopy and scanning electron microscopy (SEM), respectively.
Abstract: The plant fibers are rich in cellulose and they are easily renewable source of fibers with the potential for polymer reinforcement. The presence of surface impurities and the large amount of hydroxyl groups make plant fibers less attractive for reinforcement of polymeric materials. Hemp (Cannabis sativa L.) fibers were subjected to alkalization using 1N sodium hydroxide (NaOH). The physical, chemical, and surface properties of untreated and chemically modified fibers are studied using X-ray diffraction (wide angle X-ray scattering), Fourier transform infrared spectroscopy and scanning electron microscopy (SEM), respectively. The microstructural parameters such as crystallite size 〈N〉, lattice strain (g in %), and enthalpy (α*) have been determined by X-ray line profile analysis using Fourier method of Warren. It was found that the crystallite size 〈N〉 decreases with the increase in treatment time. SEM study shows the fibers surface becoming rough and suitable for reinforcement.
TL;DR: A unique approach for the synthesis of an iron oxide-blended sodium zinc molybdate nanocontainer using an ultrasound-assisted method and its application for 2'K epoxy polyamide nanocomposite coatings has been presented as mentioned in this paper.
Abstract: A unique approach for the synthesis of an iron oxide-blended sodium zinc molybdate nanocontainer using an ultrasound-assisted method and its application for 2 K epoxy polyamide nanocomposite coatings has been presented. Sodium zinc molybdate blended with iron oxide was used as the core of the nanocontainer and layer-by-layer assembly of oppositely charged species of polyelectrolyte and inhibitor was made over this core of nanoparticles. The release of imidazole from iron oxide-blended sodium zinc molybdate nanocontainer has been quantitatively evaluated in water at different pH. It has been observed that imidazole plays a major role in the release profile of polyelectrolyte-modified nanocontainer and deciding the corrosion inhibition characteristics. Addition of 4 wt% nanocontainer in coatings results in shifting of corrosion potential (Ecorr) value towards positive direction. The maximum concentration of imidazole released at the end of 1 h was found to be 0.545 mg L−1/g of nanocontainer at pH of 10. The...
TL;DR: In this paper, polypyrrole was synthesized and doped with functionalized multi-wall carbon nanotubes (MWCNTs) by in situ polymerization.
Abstract: Polypyrrole (PPy) was synthesized and doped with 1, 2, 4, and 8 wt.% of functionalized multi-wall carbon nanotubes (MWCNTs) by in situ polymerization. TGA/DTA analysis of nanocomposites revealed an increase in thermal stability by increasing the CNTs wt.%. Measurement of electrical resistivity showed a reduction in the resistivity of the composites at all temperatures. The glass transition temperature (Tg) of the samples was measured using electrical resistivity measurements and showed that by increasing the amount of functionalized MWCNTs in PPy, its Tg was increased. Temperature dependence of resistivity of pressed pure PPy showed that by increasing the pelletization pressure, the Tg increased. Also the hardness of nanocomposites was increased by increasing the MWCNTs wt.%.
TL;DR: Agarwal et al. as discussed by the authors proposed that cellulose-containing polymers, like bamboo rayon, are prone to microbial attack which restrains them from being used in textiles.
Abstract: Antibacterial textiles are gaining increasing importance due to consumer awareness of health and hygiene. Cellulose-containing polymers, like bamboo rayon, are prone to microbial attack which restr...
TL;DR: In this paper, structural optical and electrical conductivity properties of Li2SO4 doped with Poly (ethylene oxide) (PEO) films were characterized by using X-ray diffractometry (XRD) a...
Abstract: Structural optical and electrical conductivity properties of Li2SO4 doped with Poly (ethylene oxide) (PEO) films have been studied. The films are characterized by using X-ray diffractometry (XRD) a...
TL;DR: In this paper, the tensile and flexural properties of the hybrid composites with different layering pattern were determined and compared with pure PPLSF and jute unsaturated polyester composites.
Abstract: During the current investigation, alkali treated Palmyra palm leaf stalk fiber (PPLSF) and jute fibers were chosen as reinforcement for the unsaturated polyester matrix. Layering patterns such as bi-layer (PPLSF/jute) and tri-layer (PPLSF/jute/PPLSF and jute/PPLSF/jute) were chosen, and composites were fabricated by hand layup followed by compression molding process. The tensile and flexural properties of the hybrid composites with different layering pattern were determined and compared with pure PPLSF and jute unsaturated polyester composites. It was observed that the bi-layer composites had higher tensile properties, while the tri-layer (jute/PPLSF/jute) composites had higher flexural properties in comparison with PPLSF composites. Seventeen percent improvement in tensile strength, 51% improvement in tensile modulus for bi-layer composites and 45% improvement in flexural strength, 60% improvement in flexural modulus for jute/PPLSF/jute composites were observed in comparison with the PPLSF composites. Fr...
TL;DR: In this paper, a new method for dissolving cellulose based on phosphonium ionic liquids (PILs) was reported, which has the potential to produce novel cellulosic and cellulose composite materials in an environmentally friendly way.
Abstract: This paper reports a new method for dissolving cellulose based on phosphonium ionic liquids (PILs). The method has the potential to produce novel cellulosic and cellulose composite materials in an environmentally friendly way. PILs with melting points less than 100 °C and mixtures of dimethylformamide and PILs were used, and are recommended here, due to their negligible vapour pressure, limited reactivity, high thermal stability, and their ability to be easily recycled. The effect of the mass percent of PILs along with the comparison of the effects of different ionic liquids on the viscosity of mixtures are discussed. The limited reactivity of PILs can be used to do chemical reaction on cellulose in the presence of ionic liquids without encountering the problem of incorporation of ionic liquids in the reactions. However, if need be the PILs could also be incorporated into cellulose composites by intramolecular interactions.
TL;DR: The preliminary results indicated that the scaffold fibers were relatively uniform, and hydrophilic performance and blood compatibility were good, and the values of the tensile strength and elongation at break of vascular scaffold were 39 ± 2 MPa and 118 ± 4%, respectively.
Abstract: In this study, recombinant spider silk protein (pNSR16) was blended with polycaprolactone (PCL), gelatin (Gt), and chitosan (CS) to prepare (pNSR16/PCL/CS)/(pNSR16/PCL/Gt) bilayer small-diameter vascular scaffold through electrospinning in order to imitate multilayer structure of natural vessel. The surface morphology and properties were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, water contact angle, and mechanical tensile testing. The blood compatibility of scaffold was evaluated by recalcification coagulation time. Mesenchymal stem cells (MSC) were separated from SD rat bone marrow, and MTT assay was used to evaluate cell growth. Cell compatibility and interaction mechanism between bilayered vascular scaffold and MSC were studied. Subcutaneous implantation was performed to evaluate in vivo inflammatory reaction and degradation behavior. The preliminary results indicated that the scaffold fibers were relatively uniform, and hydrophilic performance and blood compatibi...
TL;DR: In this article, the authors showed that the formation of voids is conditioned by the geometry of self-organization of block-copolymers containing end potassium-O-polyisocyanates stabilized by crown ether fragments.
Abstract: Self-organization and arrangement of supramolecular structures from block-copolymers are some of the ways used for the development of nanoporous and mesoporous polymers. Herein, reactive olygomers can play the key role in the design of supramolecular arranging of polymers. Optically transparent mesoporuos block-copolymers with adjusted free volume are obtained by the polyaddition of 2,4-toluene diisocyanate (TDI) to anionic macroinitiators. The mechanism of polyaddition of TDI to an anionic macroinitiator in various chemical solvents was studied by infrared spectroscopy. It is established that the reaction of forming polyisocyanate blocks of acetal nature (O-polyisocyanate) and stabilization of end O-polyisocyanate chains are based on the formation of voids in polymer. The formation of voids is conditioned by the geometry of self-organization of block-copolymers containing end potassium-O-polyisocyanates stabilized by crown ether fragments. The formation of urea with the participation of isocyanate groups...
TL;DR: In this article, a multiwalled, bamboo-like carbon nanotube (BCNT)/methyl vinyl silicone (MVQ) composites with different concentrations of BCNT were fabricated by liquid blending method with an aim to investigate the properties of the composite.
Abstract: Multiwalled, bamboo-like carbon nanotube (BCNT)/methyl vinyl silicone (MVQ) composites with different concentrations of BCNT were fabricated by liquid blending method with an aim to investigate the...
TL;DR: In this paper, a computational approach was used to study the influence of porogen on the stability of template-monomer complex for rational design of molecular imprinted polymers (MIPs).
Abstract: Molecularly imprinted polymers (MIPs) are the materials mimicking the function of biological receptors and offer many possibilities for the development of novel composite materials. A computational approach was used to study the influence of porogen on the stability of template-monomer complex for rational design of MIPs. The effect of porogenic solvent was computed through polarizable continuum model, followed by the comparison of the binding energies (ΔG) of the template-monomer complexes in different porogens. MIPs were prepared for Gallic acid by thermal polymerization method, using acrylamide as functional monomer and ethylene glycol dimethacrylate as crosslinker in the presence of three different porogens, to validate the results of computational approach. The MIPs were characterized by the FT-IR, SEM, Brunauer–Emmett–Teller surface area characterization techniques and swelling analysis to study the influence of porogen on the morphology of MIPs. The performance of prepared MIPs was evaluated by bat...
TL;DR: Dodecyl amine-functionalized graphene oxide (DA-GO) was obtained via an amidation reaction as mentioned in this paper, and the results of X-ray diffraction and Fourier transform infrared spectroscopy verified that long alkyl cha...
Abstract: Dodecyl amine-functionalized graphene oxide (DA-GO) was obtained via an amidation reaction. The results of X-ray diffraction and Fourier-transform infrared spectroscopy verified that long alkyl cha...
TL;DR: In this paper, an electrically conducting polyaniline-coated halloysite nanotube (HNT-PANI) was prepared by using para-hydroxybenzene sulfonic acid as the doping agent.
Abstract: This paper reports new method of preparing electrically conducting polyaniline-coated halloysite nanotube (HNT-PANI) by using para-hydroxybenzene sulfonic acid as the doping agent. The achieved DC electrical conductivity of the HNT-PANI was 9.83 × 10−2 Scm−1. The HNT revealed no damages by the acid doping while achieving its conductive state. The HNT-PANI exhibits polaronic transitions, existence of favorable IR peaks and Raman scattering, increased thermal stability, and desirable morphological characteristic as a result of the in situ coating. Such electronically modified tube-like clay could be useful in many applications such as conductive fillers in nanocomposites and drug delivery with the advantage of being cost effective.
TL;DR: In this paper, the effects of surface treatment of polypropylene (PP) fiber on the mechanical and microstructure of fiber-reinforced cementitious composites are investigated.
Abstract: The effects of surface treatment of polypropylene (PP) fiber on the mechanical and microstructure of fiber-reinforced cementitious (FRC) composites are investigated. Surface treatment of the PP fiber was performed with 3-aminopropyltrimethoxy silane (APS) and methyltriethoxy silane (MTES) in order to improve interaction between PP fiber and matrix. The effects of APS and MTES on the surface of PP fiber are studied by scanning electron microscopy, energy dispersive spectrometer, and Fourier transform infrared spectroscopy. The experiment results indicated that the treatment of PP fiber with APS and MTES can effectively increase the adhesion between fiber and matrix, and an improvement in the flexure and compressive strength of the cementitious composites was found in the samples containing treated PP fiber compared to the samples containing untreated PP fiber. The optimized mechanical properties could be obtained using 1.0% APS (by weight) and 1.0% MTES (by weight)-treated PP fiber at studied conditions, r...
TL;DR: In this paper, the authors reported the preparation of poly(methyl methacrylate) (PMMA) nanocomposites using in-house made compatibilizer and maleic anhydride-grafted PMMA by melt intercalation in the pr...
Abstract: This work reports the preparation of poly(methyl methacrylate) (PMMA) nanocomposites using in-house made compatibilizer and maleic anhydride-grafted PMMA (PMMA-g-MA) by melt intercalation in the pr...