Hybrid Nanofillers Research Articles

Impact of Ag/ZnO Reinforcements on the Anticancer and Biological Performances of CA@Ag/ZnO Nanocomposite Materials.

In this study, an unpretentious, non-toxic, and cost-effective dissolution casting method was utilized to synthesize a group of anticancer and biologically active hybrid nanocomposite materials containing biopolymer cellulose acetate. Pristine ZnO and Ag(0.01, 0.05, 0.1)/ZnO hybrid nanofillers based on variable Ag NP loadings were prepared via green procedures in the presence of gum arabic (GA). The chemical structures and the morphological features of the designed nanocomposite materials were investigated by PXRD, TEM, SEM, FTIR, TGA, and XPS characterization techniques. The characterization techniques confirmed the formation of CA@Ag(0.01, 0.05, 0.1)/ZnO hybrid nanocomposite materials with an average crystallite size of 15 nm. All investigated materials showed two degradation steps. The thermal stability of the fabricated samples was ranked in the following order: CA/ZnO < CA@Ag(0.01)/ZnO < CA@Ag(0.05)/ZnO = CA@Ag(0.1)/ZnO. Hence, the higher Ag doping level slightly enhanced the thermal stability. The developed nanocomposites were tested against six pathogens and were used as the target material to reduce the number of cancer cells. The presence of Ag NPs had a positive impact on the biological and the anticancer activities of the CA-reinforced Ag/ZnO composite materials. The CA@Ag(0.1)/ZnO hybrid nanocomposite membrane had the highest antimicrobial activity in comparison to the other fabricated materials. Furthermore, the developed CA@Ag(0.1)/ZnO hybrid nanocomposite material effectively induced cell death in breast cancer.

Creating poly(lactic acid)/carbon nanotubes/carbon black nanocomposites with high electrical conductivity and good mechanical properties by constructing a segregated double network with a low content of hybrid nanofiller

Creating poly(lactic acid)/carbon nanotubes/carbon black nanocomposites with high electrical conductivity and good mechanical properties by constructing a segregated double network with a low content of hybrid nanofiller

Facile synthesis of 4,4′-diaminodiphenysulfone cured oleo-epoxy/PPy-PSCeO2 blend nanocomposites for anticorrosive application by in-situ and solvent-less approach

Epoxidized vegetable oil binary nanocomposite coatings are essential in various applications like space industry, rockets, satellites, automobile industry, paint industry, ceramic coatings, stealth fighter jets, solar energy harvesting etc. From the research perspective oleo-based coatings are promising materials due to biodegradable, environmentally friendly, and non-toxic nature with no release of volatile organic content into the atmosphere. Herein, we present the synthesis of promising organic-inorganic ceria doped polypyrrole modified hybrid epoxy nanocomposite coatings through in-situ and solventless approach which exhibited higher performance in acidic and saline environments (0.5 M H2SO4,0.5 M NaCl) over a long immersion period than pristine unloaded epoxy coatings. Further, the protective effect of hybrid nanoparticles i.e. PPy-PSCeO2 using DDS as a suitable hardener within the epoxy matrix was investigated. The trans-hydroxylation followed by SN2 nucleophilic substitution lead to the formation of extensive and highly dense network cross-linked 3D network with PPy-PSCeO2 hybrid nanofiller uniformly-dispersed within the matrix. The incorporation of PPy-PSCeO2 has a major contribution in the mechanistic formation of passive protective layer consisting of iron-cerium complex which thereby exhibits mechanical interlocking and barrier formation on the CS surface. Potentiodynamic polarisation, Electrochemical impedance spectroscopy and salt spray tests were carried out on coated and uncoated specimens with coated samples exhibiting enhanced mechanical properties, hydrophobic and strong acid-resistant behaviour, higher thermal stability (safely used up to 200 °C), negligible water absorption, strong adhesion and hence improvement in protection behaviour.

Unique graphene‐carbon black hybrid nanofiller by a micromechanical cleavage technique as a reinforcing agent in elastomers: Fundamental and experimental studies

AbstractIn this work, a synthetic technique was developed which effected delamination of graphite into graphene with simultaneous disaggregation of carbon black clusters and formation of secondary attachment between the two. Styrene butadiene rubber nanocomposite with this hybrid filler exhibited substantial reinforcement in the mechanical properties, wear resistance and rubber‐filler interactions. The hybrid nanofiller was superior to conventional carbon black, imparting 57% increase in tensile strength of the nanocomposite. The composite with the hybrid filler also exhibited improved modulus and traction. A detailed analysis of mechanism of reinforcement by the hybrid filler is proposed by the computation of root mean square end‐to‐end network chain distance and the lateral tube dimension employing the entangled‐bound‐rubber‐tube (EBT) model. This neoteric hybrid nanofiller overcame the so‐called dispersibility issues and could be exploited as a part of replacement of carbon black, a synthetic material from fossil fuel by sustainable natural filler.

Recent advances in tribological properties of silicon based nanofillers incorporated polymer nanocomposites

Over the last few decades, the demand for the development of polymer nanocomposites is increasing due to their excellent properties of mechanical, thermal, electrical, tribological properties and so on. The diversity of polymer nanocomposites with enhanced performances makes them suitable for a wide variety of applications such as automobile, aerospace, electrical, electronics, construction etc. The effect of various types of nanofillers such as metal-based nanofiller, carbon-based nanofiller, and silicon-based nanofiller incorporated into polymers are widely investigated by various researchers. Silicon-based nanofiller-reinforced polymer nanocomposites are prospective in recent years on tribological applications such as plastic gears, bushes, bearings, etc. A large number of different studies have demonstrated the various excellent properties of silicon-based nanofillers and hybrid nanofillers into polymer nanocomposites, however, limited reviews are being published on the effect of silicon-based nanofillers and hybrid nanofillers reinforced polymer nanocomposites. Therefore, this manuscript aims to review the recent advances on the effect of silicon-based nanofillers and hybrid nanofillers incorporated polymer nanocomposites emphasizing mainly the tribological properties. This work presents the outline of the main outcome from various studies focusing mainly on the effect of silicon-based nanofiller on friction, wear resistance and wear mechanism-related tribological properties. This work also intended to review the effect of silicon-based hybrid nanofillers into polymer nanocomposites on tribological properties. Finally, the challenges and future perspectives of silicon-based nanofillers reinforced polymer nanocomposites on the tribological properties are also discussed.

Fracture resistance of resin endocrowns with and without fiber reinforced composite base material: A preliminary study.

The aim of this study was to investigate the effects of fiber-reinforced composite base material on fracture resistance and fracture pattern of endodontically treated maxillary premolars restored with endocrowns using two different resin nanoceramic computer-aided design and computer-aided manufacturing (CAD/CAM) restorative material. Forty extracted sound maxillary premolars with an occlusal reduction of 2 mm above the cementoenamel junction (CEJ) was performed following root canal treatment. Mesial interproximal box was prepared for each tooth at the margin of the CEJ and randomly distributed into four groups (n = 10) as follows: Group A, no resin build-up in the pulp chamber; Group B, 2 mm of fiber-reinforced composite (FRC) build-up (EverX Posterior, GC).; Group C, no resin build-up in pulp chamber; Group D, 2 mm of FRC build-up. Groups A and B were prepared with resin nanoceramic (RNC) consisting ceramic nanofillers (Lava Ultimate 3 M ESPE), while Group C and D were prepared with RNC consisting ceramic nanohybrid fillers (Cerasmart GC Corp). All samples were subjected to 1,200,000 chewing cycles (1.6 Hz, 50 N) and 5000 thermal cycles (5°C-55°C) for artificial aging on a chewing simulator with thermal cycles (CSTC). Samples that survived the CSTC test without being damaged were subjected to a load-to-fracture test. The highest mean fracture strength was found in Group D (936.0 ± 354.7) and lowest in Group A (684.2 ± 466.9). Fracture strength was higher in groups where FRC was used as a base material than plain restorations. However, there were no significant differences between the Lava and Cerasmart groups with and without FRC (p > 0.05). Most of the samples were irreparably fractured under CEJ. Using short FRCs as a resin base material did not significantly improve fracture resistance. Cerasmart and Lava blocks had similar fracture resistance and fracture pattern.

Graphene Nanoplatelets/TiO2 Hybrid Nanofiller Boosted PVA/CMC Blend Based High Performance Nanocomposites for Flexible Energy Storage Applications

Graphene Nanoplatelets/TiO2 Hybrid Nanofiller Boosted PVA/CMC Blend Based High Performance Nanocomposites for Flexible Energy Storage Applications

Effects of poly(o-phenylenediamine) functionalized SiC on the corrosion protection ability of neat polyurethane coating system in the marine environment

A novel nanocomposite consisting of polyurethane (PU), poly(o-phenylenediamine) (PoPD), and silicon carbide (SiC) nanoparticles was investigated for its application in marine environment through electrochemical techniques. The PoPD/SiC nanofillers were characterized by TGA, XRD, SEM/EDX, and TEM analyses. The anticorrosion and mechanical properties of different coating formulation in marine environment were evaluated by electrochemical impedance spectroscopy (EIS) and scanning electrochemical microscopy (SECM). It was also found that the coating resistance of PU-PoPD/SiC nanocomposite was over 41 times higher than that of the PU coating. The PU-PoPD/SiC coatings on the brass showed low current of 1.9 I/nA due to copper dissolution and 6.8 I/nA due to zinc dissolution because of the well distribution of PoPD/SiC nanofiller in PU coating. The analyses of the resultant degradation products by SEM/EDX and XRD techniques confirmed the presence of Si which has a major role in protecting the brass surface against corrosion. Results showed that the PU composite with 2 wt.% PoPD/SiC hybrid nanofillers had outstanding coating performance. This nanocomposite demonstrated improved corrosion protection. As a result, the developed PU-PoPD/SiC nanocomposite has exceptional adhesion strength and anticorrosion properties and might be exploited to develop next-generation anticorrosive coatings.

Dielectric and electromagnetic interference shielding properties of nano‐silicon carbide/montmorillonite and graphene nanoplatelets filled polyvinylidene fluoride/poly(3,4‐ethylenedioxythiophene)‐block‐poly(ethylene glycol) blend nanocomposites

AbstractHerein, hybrid polymer nanocomposite films comprising polyvinylidene fluoride (PVDF) and poly(3,4‐ethylenedioxythiophene)‐block‐poly(ethylene glycol) (PEDOT‐block‐PEG) as matrices and silicon carbide nanoparticles (SiC NPs), montmorillonite (MMT) nanoclay, and graphene nanoplatelets (GNPs) as nanofillers were fabricated by solution casting. The structural, morphological, and thermal characteristics of the nanocomposite films were assessed using Fourier transform infrared spectroscopy (FTIR), x‐ray diffraction (XRD), scanning electron microscope (SEM), thermogravimetric analyzer (TGA), and differential scanning calorimetry (DSC). The SEM results show the homogeneous distribution of nanofillers within the polymer matrix. The dielectric behavior and electromagnetic interference shielding efficiency (EMI SE) of the nanocomposites were also analyzed. The maximum dielectric constant (ε) and dielectric loss (tan δ) obtained are 47.77 and 12.08, respectively, at lower frequency (50 Hz, 150°C). The maximum EMI SE was observed to be 16.8 dB in the Ku‐band region (12–18 GHz) for the nanocomposites with 20 wt% SiC, 8 wt% MMT, and 2 wt% GNPs loading. The EMI shielding was found to be absorption dominant and originated from the formation of a conductive network between hybrid nanofillers within the PVDF/PEDOT‐block‐PEG blend thereby improving the EMI SE values. These results suggest that PVDF/PEDOT‐block‐PEG/SiC/MMT/GNPs nanocomposites can be used as an efficient EMI shielding material.

Sulfonated polyether ether ketone composite proton exchange membranes incorporated with a novel hierarchical‐structure hybrid nanofiller consisting solid superacid zirconium phosphate and CNTs

AbstractHow to simultaneously improved the proton conductivity and mechanical strength is a key problem facing currently used proton exchange membranes (PEMs). Herein, a solid inorganic superacid‐zirconium phosphate (ZrP) with a two‐dimensional layer structure was combined with one‐dimensional carbon nanotubes (CNTs) to prepare hybrid nanofiller ZrP‐CNTs by an in situ chemical deposition method. The new hybrid nanofiller was then applied to modify sulfonated polyether ether ketone (SPEEK), a widely used PEM matrix, to obtain a series of composite membranes. The structure and properties of the membranes were fully characterized by SEM, XRD, FTIR, TG, tensile properties, and proton conductivity. The results showed that the proton conductivities of the membranes were significantly improved due to the addition of super solid acid‐ZrP that has abundant proton sources or proton sites. Moreover, the composite membranes exhibited better mechanical properties and thermal stability than those of pure SPEEK membrane, owing to the great interface interaction and good compatibility between ZrP‐CNTs and SPEEK. The composite membrane (2 wt% ZrP‐CNTs) demonstrated the optimal comprehensive performance. Its proton conductivity was 36.63 mS cm−1 and its tensile strength was 37.56 MPa, which was 70% and 10%, respectively, higher than those of the pure SPEEK membrane under the same condition.

Graphene nanoplatelets/barium titanate hybrid nanoparticles via ball milling for enhanced dielectric and mechanical properties of fluorosilicone rubber composites

Dielectric elastomers have been widely used in flexible actuators, artificial muscles, soft generators, etc. However, there are still challenges in fabrication of dielectric elastomers with enhanced dielectric and mechanical properties through simple and environmentally friendly compound method. In this paper, graphene nanoplatelets (GNPs) and BaTiO3 (BT) hybrid nanofillers are prepared by co-ball milling and then introduced into fluorosilicone rubber (FSR) to obtain composites with improved dielectric and mechanical properties. The X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy and transmission electron microscope results confirm the successfully exfoliation of GNP. With the increase of GNP content, the tensile strength and dielectric constant of FSR/GNP/BT nanocomposites both increase without the sacrifice of flexibility, while the dielectric loss tangent can be kept as low as 10−2 magnitude. The FSR-G7B30-BM composite exhibits a dielectric constant of 14.54 at 100 Hz, and the dielectric loss tangent of 0.016 at 100 Hz. Besides, the FSR-G7B30-BM composite displays the tensile strength of 1.19 MPa, and elongation at break of 332.12%. This work provides a facile strategy to design dielectric elastomers, which shows promising applications in modern electronic devices.

Cellulose Nano Crystal/Graphene Nano Platelets Hybrid Nanofillers reinforced Polylactic Acid Biocomposites: Mechanical and Morphological Properties

Polylactic acid (PLA) reinforced by hybrid nanofillers biocomposites had been prepared using a melt blending and compression molding technique. The mechanical properties of the PLA biocomposites was studied by incorporating various ratio of cellulose nano crystal (CNC)/graphene nano platelets (GNP) hybrid nanofillers into PLA. The morphological characterization was also carried out using field emission scanning electron microscopy (FESEM) to correlate the fracture surface and nanofiller dispersion with the mechanical properties of the composites. The result show that, at the same CNC/GNP hybrid nanofiller loading (3wt %), the strength properties (tensile and flexural) of PLA biocomposites decreased with increment GNP over CNC ratio. 37.35 MPa and 53.87 MPA; 54.71 MPA and 68.22 MPA, respectively. Meanwhile, PLA biocomposites demonstrated a slight increase in tensile modulus as the GNP ratio is higher than CNC. According to the findings, CNC played an important role in enhancing strength properties while GNP was effective in enhancing the modulus properties. The morphological studies by FESEM prove that, there are relationship between fracture surface and filler dispersion with the mechanical properties of PLA biocomposites.

Reinforcement of PP with a hybrid nanofiller; comparison to talc

Polypropylene composites were prepared with a new, commercially available hybrid nanofiller and talc as a reference. The detailed analysis of the nanofiller proved that its two components are sepiolite and possibly laponite and that it was surface coated with an ammonium ion having long aliphatic chains. The results showed that the concept of hybridization does not necessarily work in all cases. Although an even, homogeneous spatial distribution of the nanofiller was achieved, the nanosized filler particles aggregated above the filler content of 3 wt%. Model calculations yielded a slightly larger reinforcing effect for the nanofiller compared to talc. On the other hand, the absolute values of the most important mechanical properties achieved by the addition of the nanofiller were somewhat worse than those obtained for the talc filled composites. The presence of aggregates and weak interfacial interactions resulting from surface treatment led to only a moderate performance of the nanocomposites.

Mechanical and thermal performances of styrene butadiene rubber nanocomposites with boron nitride nanosheets, carbon nanotubes, and the hybrid filler system

AbstractPreparation of rubber nanocomposites using two or more nanofillers with different geometries is a new and promising approach. In this work, the effects of boron nitride nanosheets (BNNS), carbon nanotubes (CNT) and their hybrid (BNNS‐CNT) on the performances of styrene butadiene rubber (SBR) nanocomposites are systematically studied. The mechanical properties of the nanocomposites are significantly enhanced by the nanofillers. The tensile strength of unfilled SBR is only 1.30 ± 0.18 MPa, which increases to 1.72 ± 0.24 MPa (BNNS), 4.09 ± 0.35 MPa (CNT), and 3.37 ± 0.29 MPa (BNNS‐CNT) at 4 phr, respectively. Similarly, the tear strength of unfilled SBR is 8.0 kN/m, which increases to 13.8 kN/m (BNNS), 16.1 kN/m (CNT) and 18.2 kN/m (BNNS‐CNT) at 4 phr, respectively. Moreover, the thermal behavior of the nanocomposites are analyzed. Compared with single nanofiller BNNS or CNT, BNNS‐CNT hybrid nanofiller not only effectively improves the mechanical properties of nanocomposites, but also imparts better thermal properties. It is proved that the thermal decomposition temperature of SBR/4phr BNNS‐CNT is increased by nearly 7°C compared with unfilled SBR.

Elevated‐temperature mechanical performance of GFRP composite with functionalized hybrid nanofiller

AbstractIn this article, alteration in the mechanical performance of glass fiber/epoxy (GE) composite due to individual and simultaneous incorporation of multi‐walled carbon nanotubes (CNT) and multi‐layered graphene sheets (MLG) in both their pristine and oxidized forms are discussed. Further, the effect of two different nanofiller concentrations (0.1 and 0.3 wt%) were also studied to optimize the performance. Flexural testing of these composites was performed at room temperature (RT), 70 and 110°C in‐situ temperatures to understand their temperature dependence behavior. From all considered composites, GE composite with 0.1 wt% of oxidized CNT and MLG mixture (O‐(CNT‐MLG)) (1:1) showed best flexural performance at all the in‐situ temperatures. The presence of oxidized CNTs and MLGs in the GE composite provided a synergetic strengthening effect like CNT pull‐outs and crack bridging confirmed through SEM imaging. Besides, oxidation helped in the dispersion of CNT and MLG in the composite. Glass transition temperature (Tg) of all the considered composites was evaluated using Differential Scanning Calorimetry (DSC). Fourier Transformed Infra‐red Spectroscopy (FTIR) was also conducted to confirm the functionalization of CNT and MLG after oxidation. During the fractography study, these composites showed variation in fiber/matrix interfacial bonding, matrix deformation, dispersion of nanofillers and fiber imprints, which helped to understand different failure modes responsible for the gross failure of the composites.

A green dual-phase carbon-silica nanohybrid derived from black liquor lignin for reinforcing styrene-butadiene rubber

In rubber industry, lignin has been investigated as a potential alternative of fossil-derived carbon black (CB) for several decades. However, due to poor dispersity, big particle size and incompatibility with rubber, lignin cannot achieve the same reinforcing effect as CB by direct dry mixing. Here, a new and green dual-phase carbon-silica nanohybrid (LDPCS) was successfully prepared from black liquor lignin (BLL) and sodium silicate through a simple co-gelation/self-assembly and carbonization process. The preparation mechanism and process as well as the morphology and properties of LDPCS were investigated and discussed in detail. The results indicated that the hydroxymethylation and silane modification of BLL could improve its affinity with SiO2 sols, thus facilitating the co-gelation of BLL and SiO2 sols to inhibit the growth of SiO2 particles. During subsequent acid precipitation, silane modified hydroxymethylated BLL (SiHM-BLL) was self-assembled around SiO2 particles to form nanosized SiHM-BLL-SiO2 hybrids. After carbonization, SiHM-BLL-SiO2 nanohybrids were converted into LDPCS with small primary particle size of 60–90 nm, high specific surface area of 82.19 m2/g, relatively loose secondary aggregation structure and graphitic microcrystals in the carbon framework. With incorporating LDPCS into styrene-butadiene rubber (SBR) by direct dry mixing, LDPCS showed a superior reinforcing capability for SBR as compared with CB, which was ascribed to the nanoscale dispersion of LDPCS, robust C/SiO2 interfaces and high affinity with SBR matrix. This work provided a new insight into the fabrication of novel hybrid nanofiller from lignin and broadened the potential applications of lignin in rubber compounds and beyond.

Effect of vertical aligned carbon nanofiber/carbon nanotube on the mechanical, electrical and electromagnetic interference shielding properties of epoxy foams

In this study, one-dimensional (1D) carbonaceous blends containing multi-walled carbon nanotube (MWCNT) and carbon nanofiber (CNF) were added into epoxy resin (EP) to obtain hybrid powder though ball milling. Limited foam with vertically aligned nanofillers was fabricated through limited-foaming epoxy hybrid in a mold and Two-step foam was prepared by further freely foaming a preformed Limited foam in an oven. The cellular structure, compressive, electrically conductive and EMI shielding properties of these two kinds of epoxy composite foams were carefully investigated. Limited foam showed an isotropic electrical resistivity while the electrical anisotropy started to emerge after the second-step foaming. This result was ascribed to the twisty MWCNT bridged the aligned CNF to build conductive pathways in horizontal direction, thus eliminating the electrical anisotropy of Limited foam. However, these loose interconnections between MWCNT and CNF in horizontal direction were more seriously destroyed by the further growth of bubbles, consequently endowing the Two-step foam with electrical anisotropy. Adding CNF into EP/MWCNT foams not only improved the electromagnetic interference (EMI) shielding effectiveness (SE), which was due to the synergistic effect between hybrid nanofillers in enhancing the electrical conductivity, but also enlarged the anisotropy in EMI SE of both Limited foam and Two-step foam. As compared to anisotropic bubbles, the vertically aligned MWCNT/CNF in composite foams exhibited a weak effect on anisotropy in compressive strength. Moreover, a remarkably anisotropic expansion behavior of preformed foam during the second-step foaming was observed and this behavior can be tuned by the ball milling time and the content of vertically aligned nanofillers.

Hybrid composites based on carbon nanotubes and graphene nanosheets outperforming their single-nanofiller counterparts

The electrical properties of epoxy hybrids filled with Graphene Nanosheets (GNs) and Multi-Wall Carbon Nanotubes (MWCNTs) were investigated by Tunneling Atomic Force Microscopy (TUNA) to understand the correlation between electrical conductivity, on a micro/nano space scale, and the arrangement of the electrically conductive paths through the sample. Two different amounts of mixed fillers, namely below 0.1 wt% and above 0.5 wt%, were dispersed by ultrasonication into a tetrafunctional epoxy matrix at five different MWCNTs:GNs mix ratios. At a low amount of nanoparticles, 0.1 wt%, the hybrid nanofiller concentration allows for detecting a very interesting synergy toward an increase in the electrical conductivity of several orders of magnitude, and a lowering of the Electrical Percolation Threshold (EPT). Both the computational and experimental results highlight that, owing to the hybrid MWCNT/GNs network formation, the hybrid nanocomposites outperform their single-nanofiller counterparts.

Hybrid Nanofillers Creating the Stable PVDF Nanocomposite Films and Their Effect on the Friction and Mechanical Properties.

The solvent casting method was used for five types of polyvinylidene difluoride (PVDF) nanocomposite film preparation. The effect of nanofillers in PVDF nanocomposite films on the structural, phase, and friction and mechanical properties was examined and compared with that of the natural PVDF film. The surface topography of PVDF nanocomposite films was investigated using a scanning electron microscope (SEM) and correlative imaging (CPEM, combinate AFM and SEM). A selection of 2D CPEM images was used for a detailed study of the spherulitic morphologies (grains size around 6–10 μm) and surface roughness (value of 50–68 nm). The chemical interactions were evaluated by Fourier transform infrared spectroscopy (FTIR). Dominant polar γ-phase in the original PVDF, PVDF_ZnO and PVDF_ZnO/V, the most stable non-polar α-phase in the PVDF_V_CH nanocomposite film and mixture of γ and α phases in the PVDF_V and PVDF_ZnO/V_CH nanocomposite films were confirmed. Moderately hydrophilic PVDF nanocomposite films with water contact angle values (WCA) in the range of 58°–69° showed surface stability with respect to the Zeta potential values. The effect of positive or negative Zeta-potential values of nanofillers (ζn) on the resulting negative Zeta-potential values (ζ) of PVDF nanocomposite films was demonstrated. Interaction of PVDF chains with hydroxy groups of vermiculite and amino and imino groups of CH caused transformation of γ-phase to α. The friction properties were evaluated based on the wear testing and mechanical properties were evaluated from the tensile tests based on Young’s modulus (E) and tensile strength (Rm) values. Used nanofillers caused decreasing of friction and mechanical properties of PVDF nanocomposite material films.

Polyaniline-Grafted Chitin Nanocrystals as Conductive Reinforcing Nanofillers for Waterborne Polymer Dispersions.

Due to its intrinsic electrical conductivity, polyaniline (PANI) is one of the most promising conducting polymers for high-performance applications in a wide range of technological fields. However, its poor dispersibility in water and organic solvents markedly imparts its processability and electrical conductivity. Herein, we report a green and one-step approach to preparing stable colloidal dispersions of highly dispersible hybrid nanoparticles by polymerizing PANI onto chitin nanocrystals (ChNCs) as biotemplates, via initiation through the surface amino groups of ChNCs. Evidence of the grafting of PANI onto ChNCs was supported by transmission electron microscopy (TEM), as well as Raman and Fourier transform infrared (FTIR) spectroscopies. Nanocomposite films were prepared by mixing the PANI-g-ChNCs with a waterborne poly(vinyl acetate) latex dispersion followed by casting and film formation at room temperature. The mechanical properties were tested as a function of the PANI-g-ChNC content. In addition, it was shown that at a proper content of PANI in ChNCs, and over a critical loading in the PANI-g-ChNCs, a conductive film was obtained, without sacrificing the reinforcing effect of the rodlike nanofiller. As a potential application, conductive waterborne adhesives for wood were prepared and the performance of the adhesives was tested. This research provides a facile route to fabricating a new class of hybrid nanofiller from a biobased origin, stable in water and easy to mix with waterborne dispersions, combining the merits of the ChNC nanofiller with the conductivity of PANI.