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High thermally conductive polymer composites have garnered significant attention due to their exceptional performance, given the ever-decreasing size of electronic devices and the rise in power densities. Herein, a new three-dimensional (3D) thermal conductivity network structure has been successfully prepared using double fillers of nickel foam (NF) and modified silicon carbide particles (KSiC). The study compared the effect of different filler contents on the thermal conductivity of composites. Compared to conventional composites, those based on 3D filling networks have significantly improved thermal conductivity. The thermal conductivity of the NF/KSiC/PU composite containing 50 [w.sub.t]% KSiC was 1.18 [Wm.sup.-1] [K.sup.-1], exceeding the cumulative thermal conductivity of the NF/PU and KSiC/PU 50 [w.sub.t]% composites, and 637.5% greater than that of neat PU. Meanwhile, the synthesized NF/KSiC/PU composite maintained a high electrical resistivity above [10.sup.12] [ohm]-cm and good mechanical properties. This approach might offer novel solutions for developing high-quality packaging materials for advanced electronic devices with exceptional thermal and mechanical properties. Highlights * Using SiC and NF Constructs a dual filler network. * The dual filler thermal conductivity network can generate synergistic effects. * Improving thermal conductivity compared to original polyurethane. * Maintaining a high electrical resistivity and good mechanical properties. KEYWORDS polyurethane, silicon carbide, thermal conduction network, thermal management material, 1 | INTRODUCTION In recent times, the continual progress of integrated circuits has resulted in increased chip integration levels and power densities. Nevertheless, this has led to heat accumulation, necessitating [...]

In this paper, we examined the effects of transition metal replacement and ordering in 2D [M.sub.3][C.sub.2][O.sub.2] MXene on the electronic structure and thermal and electrical conductivities using the density functional theory and also Boltzmann's transport theory within the constant relaxation time approximation. We derived the following oxygen-functionalized ordered double-metal MXenes T[i.sub.2]Y[C.sub.2][O.sub.2], [Y.sub.2]Ti[C.sub.2][O.sub.2], S[c.sub.2]Y[C.sub.2][O.sub.2], and [Y.sub.2]Sc[C.sub.2][O.sub.2] through the surface and sub-layer tuning. The results revealed that the ordered MXenes give rise to different electronic structure and transport properties. The electronic thermal conductivities obtained in terms of the relaxation time increase with increase in absolute temperature, while the electrical conductivities decrease with increase in temperature. The respective transport properties of [Y.sub.2]Ti[C.sub.2][O.sub.2] and S[c.sub.2]Y[C.sub.2][O.sub.2] were found to be enhanced due to the increased squared band velocity, density of state, and low Seebeck coefficient compared to T[i.sub.2]Y[C.sub.2][O.sub.2] and [Y.sub.2]Sc[C.sub.2][O.sub.2] MXenes. Generally, the MXene materials investigated in this work were found to possess metallic properties with the existence of energy overlap around the Fermi level. The computed formation energies support chemical stability in all the materials. Key words: MXenes, density functional theory, Boltzmann's theory, thermal conductivity, electrical conductivity, Introduction Two-dimensional (2D) materials have emerged as the cornerstone of device fabrications due to their wide surface area compared to their bulk counterparts. Also, in contrast to bulk materials, 2D [...]

Buffer materials that are used to isolate heat-emitting waste canisters must bear a strong thermal load and have good thermal conductivity and stability. This study investigated the strengthening of internal thermal conduction via bentonite sealing. An admixture of quartz and graphite accelerated the heat transfer into the host rock. Samples containing different bentonite-sand-graphite (BSG) mixtures were prepared. The influence of the volumetric water content, degree of saturation, dry density, porosity, sand content, and particle size on the thermal conductivity of the BSG mixtures was analyzed by conducting a series of thermal needle tests. Electrical resistivity tests were conducted to examine the electrical resistivity of the BSG mixtures, and the dependency of soil thermal conductivity on the volumetric water content based on electrical resistivity data. The results indicated that the dependency of thermal conductivity on the volumetric water content was closely related to electrical resistivity. Based on the thermal conductivity inflection point as determined by the volumetric water content corresponding to the electrical resistivity inflection point, an improved series-parallel thermal conductivity prediction model and the method to determine model parameters for the unsaturated BSG mixtures were proposed. The precision of the proposed prediction model was verified based on laboratory data. Key words: BSG mixtures, buffer material, thermal conductivity, electrical resistivity, prediction model, 1. Introduction and background In the conceptual design of high-level radioactive waste (HLRW) repositories, the thermal performance of the buffer material is one of the key factors considered in the [...]

Abstract This work aims to correlate the dispersion tendencies and the cause/effect relationships that are generated when a carbonaceous nanofiller is disseminated in three different elastomer matrices. We have incorporated [...]

A new generation conductive thermoplastic vulcanizates (CTPVs) have been developed and characterized in detail, which is based on ultra-high molecular weight (UHMW)-EPDM rubber combined with conductive carbon black (CCB) filler. The influence of incorporation of CCB filler in the CTPV matrix on various relevant properties has been studied thoroughly. Physicomechanical properties indicate a significant improvement in the tensile strength, modulus, crosslink density, and tear strength together with quite good flexibility of the CTPVs. Rheological properties depict excellent processability and material strength (storage-modulus and complex-modulus), and stress relaxation shows a higher relaxation time of the CTPVs over the pristine-TPV. Morphology study (AFM, FESEM, and TEM) reveals very well dispersion of the CCB-filler and droplet type dispersed morphology has been achieved. The study of the electrical properties demonstrates that fair AC conductivity can be achieved for high filler loading. AC impedance analysis also proves the improvement for CTPVs over the pristine TPV. It is well described that due to the incorporation of the CCB-filler, all the properties are improved, and from some of the results amount of CCB-filler can also be optimized. UHMW-EPDM/PP-based conductive TPVs (CTPVs) can be potentially used as a sensitive stretchable conductor for various applications. KEYWORDS conductive carbon black, conductive thermoplastic vulcanizates, TEM, UHMW-EPDM, 1 | INTRODUCTION In this modern era, conductive polymer composites (CPCs)-based wearable and flexible strain sensors have attracted extensive popularity due to their superior sensing performances and ease of processing. [...]

The rising trend of electromagnetic pollution has motivated us to develop a novel electromagnetic interference shielding (EMI) material by adopting a facile, industry viable, and cost-effective solution mixing strategy. Single-walled carbon nanotubes (SWCNT) as conductive fillers is employed in a lightweight, highly flexible ethylene methyl acrylate (EMA) polymer to fabricate the superior electrically conductive and efficient EMI shielding material at a relatively lower percolation threshold limit compared to other carbonaceous fillers has been justified by their morphological characterization. The electrical conductive network formation is attained at just 1.96 wt% of SWCNT loading resulting in more than 20 dB of EMI shielding effectiveness (EMI SE) dominated by absorption mechanism to fulfill the industrial requirement along with excellent mechanical properties improvement, and the highest SE is 45 dB at 15 wt% of reinforcement facilitating their potential use in both industry and academia. KEYWORDS electrical properties, EMI shielding effectiveness, ethylene methyl acrylate, mechanical properties, percolation threshold, single-walled carbon nanotubes, 1 | INTRODUCTION Over the last two decades, there has been extensive growth in the electrical, electronics, and telecommunication industry, resulting colossal amount of electromagnetic pollution in the form of [...]

Electromagnetic interference (EMI) shielding rubber nanocomposites were fabricated via a simple rubber roll milling technique based on the filler distribution behavior in the immiscible natural rubber (NR) and acrylonitrile-butadiene (NBR) (50/50) blends with varying amounts of multiwall carbon nano tubes and [Fe.sub.3][O.sub.4] nanoparticles. All nanocomposites showed a co-continuous phase structure, while the distribution behavior of filler was diverse correlated with the filler content and type. The mechanical properties, electrical conductivity, and EMI shielding effectiveness (SE) of rubber composites were characterized. The maximum EMI SE of 29.4 dB at 12.4 GHz was achieved in the rubber composites loaded with 15 phr MWCNTs and 15 phr [Fe.sub.3][O.sub.4] nanoparticles. The EMI shielding mechanisms of such materials were also discussed. The observation in this work provided a possible idea to the industrial manufacture electromagnetic interference shielding rubber nanocomposites, and contributed to expanding its application fields with higher mechanical property requirements and flexibility. KEYWORDS electromagnetic interference shielding, immiscible rubber blend, mechanical properties, polymer-matrix composites, 1 | INTRODUCTION With extensive applications of electronic and telecommunication devices in daily life, electromagnetic pollution has become one of the serious environmental problems because of its adverse effects on [...]

Here, we propose a composite system made of 2D-[Ti.sub.3][C.sub.2] and two different chemical forms of polyaniline (PANI) like polyemeraldine base (EB) and polyemeraldine salt (ES) to investigate their electrochemical performances as supercapacitor electrode material. Fundamentally, EB and ES are having different functionalities and electrical conductivities to affect their electrochemical performances. Thus, synthesis and electrochemical performances of the composites made of [Ti.sub.3][C.sub.2] and ES or EB with different compositions is discussed where [Ti.sub.3][C.sub.2]/ES form of PANI appears as best performing supercapacitor electrode with the areal capacitance of 1.85 [Fcm.sup.-2] at 5 [mVs.sup.-1]. A capacitance enhancement of 5.4 times was observed for [Ti.sub.3][C.sub.2]/PANI-ES while compared to the same for bare [Ti.sub.3][C.sub.2] with capacity retention of 91.70% after 500 cycles at 1 [Ag.sup.-1]. This work has also explored the effect of composite compositions by varying the stoichiometric weight ratios of [Ti.sub.3][C.sub.2] and different forms of PANI to achieve high-performing supercapacitor electrode materials. KEYWORDS interfacial charge transfer, MXene, polyaniline, polyemeraldine salt, supercapacitor, 1 | INTRODUCTION Energy and environmental issues are the greatest challenges faced by humanity in the 21st century. Exploration and utilization of new energy sources including wind and solar energy [...]

Ceramic/polymer nanocomposites have been extensively explored for dielectric capacitor application due to their high energy storage performance and ease of processing, flexibility, and low cost. However, improving compatibility between inorganic and organic materials is of great significance and has been a long-standing challenge. In this work, the polymer surfactant Pluronic[TM] F127 was employed to perform surface modification of Ba[TiO.sub.3] through a facile solution process. The compatibility between Ba[TiO.sub.3] nanoparticles and P (VDF-HFP) can be remarkably strengthened by the affinity between F127 polymer chains and the organic matrix. Structural defects such as pores, cracks, and agglomeration of inorganic particles were obviously reduced, and interfacial polarization has been significantly enhanced. The discharged energy density [U.sub.d] and charge-discharge efficiency [eta] reach up to 5.0J/[cm.sup.3] and 58.1% under the breakdown strength of 3740 kV/cm for the nanocomposite containing 1 vol% BT@F127. These dielectric properties are clearly better than the nanocomposite using unmodified BT, as well as similar hybrids reported previously. KEYWORDS ceramic/polymer nanocomposite, dielectric property, energy density, surface modification, 1 | INTRODUCTION Dielectric capacitors are the basic components of energy storage in modem electronic and electrical systems. They have been widely used in the fields of power transmission, hybrid [...]

The in-mold coating (IMC) process nowadays is well accepted by the sheet molding compound industry. The currently used IMC contains 2.8 wt% carbon black (CB) to provide enough electrical conductivity for maximum paint transfer efficiency (PTE) for electrostatic painting. Due to its relatively large viscosity, this formulation makes use of more than one injection gate for coating some large parts necessary. Our previous research investigated the possibility to replace the CB with higher conductivity carbon-based nanoparticles, namely carbon nanofibers (CNFs), multi-wall carbon nanotubes (MWCNTs), industrial graphene (grapheneblack [G]), and single-wall carbon nanotubes (SWCNTs) and found that the IMC with 11.3 wt% G has the best processability among all IMC formulations. To improve this formulation, herein, we study the use of a second reinforcement in combination with G, i.e., CB, CNF, and MWCNT. Results from this study suggest that most G/CB-reinforced IMC formulations have a better performance than the G-reinforced IMC formulations, and IMC with 1 wt% CB and 6 wt% G is the best among all G/CB-reinforced IMC formulations. To be specific, the new formulation allows parts to be painted to have a 300% increase in size when compared with the standard IMC. KEYWORDS carbon black, carbon nanofiber, electrostatic painting, grapheneblack, in-mold coating, multi-wall carbon nanotube, two-reinforcement formulations, 1 | INTRODUCTION Sheet molding compound (SMC) has been widely accepted by automotive, trucking, and appliances industries for its high strength-to-weight ratio and cosmetic appeal. The SMC is compression molded [...]

In this work, polyaniline nanorod adsorbed on reduced graphene oxide (P@G) hybrid filler was prepared via in situ polymerization of aniline monomer in the presence of reduced graphene oxide as template. Fourier transform infrared, X-ray diffraction, field emission scanning electron microscopy, and highresolution transmission electron microscopy images revealed the formation of P@G hybrid. The P@G hybrid was dispersed in dichlorobenzene and then introduced into epoxy resin at different loadings. The epoxy nanocomposites containing 9 wt% P@G hybrids (E/P@G9) exhibited a maximum DC conductivity of 1.34 * [10.sup.-5] S/cm that is eight orders higher compared to pure epoxy. At [10.sup.3] Hz, a dielectric constant ([epsilon]') of 163 was attained for E/P@G9, nearly 34 times higher than pure epoxy. A percolation threshold of 4 vol% was observed for [epsilon]'. Dynamic mechanical studies showed that significant enhancement in storage modulus values were exhibited for 3 and 5 wt% of hybrids. The glass transition temperature showed a maximum shift of 10[degrees] C to higher temperatures at 3 wt% loading of P@G hybrids (E/P@G3). The tensile strength, Young's modulus, and impact strength of the E/P@G3 nanocomposites enhanced by 19.7, 72, and 12%, respectively. The thermal stability of the epoxy nanocomposites also enhanced with the addition of P@G hybrid. KEYWORDS DC conductivity, dielectric properties, dynamic mechanical properties, epoxy, graphene, PANI adsorbed graphene, PANI nanorod, thermally reduced graphene oxide, 1 I INTRODUCTION With the rapid growth in the field of electronic systems, immense efforts have been made by researchers to develop materials exhibiting high permittivity. Polymer/ conducting filler composites [...]

In this article, the effect of the addition of graphene oxide (GO) and reduced graphene oxide (rGO) on the mechanical properties, thermal stability, and electrical conductivity of polyvinyl alcohol (PVA) has been investigated. Different weight percentages of nanofillers ranging from 0.5 to 5 wt% have been combined with PVA. The ultrasonic technique has been applied to disperse nanofillers in the PVA solution. The nanocomposite films have been prepared via solution casting technique and the dispersion of nanofillers into the PVA has been studied through optical microscopy. The microstructure, crystallization behavior, and interfacial interaction were characterized through X-ray diffraction and Fourier transform infrared spectroscopy. Differential scanning calorimetry (DSC) and thermogravimetric analysis have been applied to study the thermal properties of the prepared nanocomposites. The DSC results revealed that the crystallization temperature and melting temperature were enhanced in the presence of GO nanofiller. Besides, the tensile strength at break was improved along with the addition of GO; however, elongation at break for PVA/GO and PVA/rGO was diminished. Moreover, all specimens showed insulating behavior and the only sample was electrically conducting, which contain a high amount of rGO (5 wt%). KEYWORDS interfacial interaction, mechanical properties, nanocomposites, thermal properties, thin films, 1 | INTRODUCTION Poly(vinyl alcohol) (PVA) is a synthetic thermoplastic polymer that is made from partial or complete hydrolysis of polyvinyl acetate. [1] PVA is soluble in water and it [...]

The industrial developments have led to more applications of various composites. Since fiber orientation and distribution will influence product performance in composites, controlling said orientation and distribution is of critical importance. This study used external magnetic fields to control the fiber orientation and distribution in a polymer. The orientation of the actual fibers under magnetic field control during flowing was observed using a visualization system, which was made by PMMA and transparent epoxy as an upper cover and filling polymer. In order to clearly observe and calculate, 0.1 wt% fiber content was used, and 0.3 wt% fiber content was used to measure conductivity. Fiber distribution angles without a magnetic field concentrate parallel to the flow direction (0[degrees] ~ 30[degrees] and 151[degrees] ~ 180[degrees]) while distribution angles under magnetic field control were concentrated along the magnetic field direction, which was perpendicular to the flow direction (61[degrees] ~ 120[degrees]). The higher the magnetic flux density, the larger the torque of the electromagnetic field on the fibers and the higher the orientation of fibers was with the magnetic field. The electrical conductivity was 12.23 times higher for 1 mm fibers in an external magnetic field versus no magnetic field. KEYWORDS composite, electrical conductivity, fiber orientation, magnetic fields, magnetic torque, 1 | INTRODUCTION To meet higher demand for product quality performance of computer and electronic products, the development of science and technology is oriented toward lightweight and compactness. As more [...]

Monitoring the curing behavior of a thermosetting material is a key issue for ensuring a stable manufacturing process (e.g., injection molding). Dielectric analysis (DEA), which is applicable for online-monitoring, is used to investigate the curing behavior of a glass-fiber-reinforced epoxy molding compound. At first, the influences of experimental settings (pressure, temperature, and frequency) on'dielectric responses (dielectric loss and ion viscosity) are characterized in a fully crosslinked material. Results show a significant impact of temperature and frequency on dielectric responses. Furthermore, DEA is combined with differential scanning calorimetry (DSC) to investigate dielectric properties depending on crosslink density under non-isothermal and isothermal conditions. The results show that DEA can detect cure changes only for a crosslink density KEYWORDS cure behavior, DEA, dielectric properties, DSC, epoxy, reaction kinetics, 1 | INTRODUCTION Thermosets that are widely used in industry are reactive polymers. Non-cured thermoset material contains many monomers, which start to crosslink from a specific temperature during processing. Three-dimensional [...]

Polyvinylidene fluoride (PVDF) is a preeminent pyrolytic and piezoelectric polymer. It has been widely studied as an ideal material for wearable flexible sensors or low-power electronic equipment. PVDF/ZnO thin films were prepared by direct writing method, which promoted the ordered arrangement of PVDF molecular chains under the action of electric field and thus improved the crystallinity of the [beta] phase. Meanwhile, the effects of intercalation of ZnO nanoparticles on the crystallinity of PVDF thin films were explored. The results show that appropriate addition of nano-ZnO as nucleating agent can induce the crystallinity of the PVDF film obviously. While the additive amount of nanoparticles was 0.02 wt%, the relative [beta] phase content of the PVDF film can reach 88.92%. Under the double action of adding ZnO nanoparticles and electric field assistance, the dielectric constant of the composite film increases from 6.9 (pure PVDF) to 12.4 (0.03 wt% ZnO) at a frequency of 1 kHz. The [d.sub.33] value of the film without polarization is up to -9.1 pC/N, the output voltage is increased to 351 mV, and the conductivity of the composite film has been improved. KEYWORDS crystallization, dielectric properties, microstructure, thin film, 1 | INTRODUCTION With the vigorous development of the intelligent industry, many wearable electronic products have entered our daily lives. Choosing a suitable sensor is crucial for wearable electronic devices. [...]

Canadian Malartic is an Archean low-grade bulk tonnage native gold deposit. The deposit is mostly located in altered clastic metasedimentary rocks, mafic-ultramafic dykes, and monzodioritic porphyry intrusions. Airborne magnetic and frequency-domain electromagnetic (EM) data were inverted to reconstruct the geological units associated with the mineralization, especially the intrusive masses. The 3-D inversion of magnetic data, which used a tetrahedral mesh to a depth of 2.4 km, shows that mafic volcanic rocks and iron formation rocks extend to depth in the area, more so than diabase dykes. The magnetic inversion also shows that the diorite and monzodiorite rocks of the Lac Fourniere A pluton are dipping toward the south on its northern edge at the contact with the metasedimentary rocks. The 1-D inversion of the frequency-domain EM data, for both electrical conductivity and magnetic susceptibility, is able to reconstruct geological structures to a depth of approximately 100 m, providing more details and information about these features. The intrusive masses such as diabase dykes, diorite and monzodiorite rocks, and mafic volcanic rocks are reconstructed as electrically conductive structures in the inversion results. The metasedimentary rocks are resistive, and the overburden is conductive in most of the area. The geophysical data and inversion results suggest the presence of some features (such as diabase dykes and monzodiorite rocks) that are not yet present on some parts of the geology map. A comparison of the EM-derived susceptibility and the magnetic-derived susceptibility over the iron formations can reveal the effect of remanent magnetization. Key words: Canadian Malartic area, gold exploration, inversion method, magnetic and electromagnetic methods. Le gisement Canadian Malartic est un gisement d'or natif a fort tonnage et faible teneur. Le gisement est princi-palement encaisse dans des roches metasedimentaires clastiques alterees, des dykes mafiques-ultramafiques et des intrusions de porphyre monzodioritique. Des donnees aeromagnetiques et d'induction electromagnetique (EM) en domaine de frequence ont ete inversees pour reconstituer les unites geologiques associees a la mineralisation, en particulier les masses intrusives. L'inversion 3D des donnees magnetiques, qui emploie une maille tetraedrique jusqu'a une pr1ndeur de 2,4 km, montre que des roches volcaniques mafiques et des roches de formation de fer sont presentes en profondeur dans la region, plus que des dykes de diabase. L'inversion magnetique montre egalement que les roches dioritiques et monzodioritiques du pluton de Lac Fourniere A ont une plongee vers le sud a sa limite nord au contact avec les roches metasedimentaires. L'inversion 1D des donnees EM en domaine de frequence, tant pour la conductivite electrique que pour la susceptibilite magnetique, permet de reconstituer les structures geologiques jusqu'a une profondeur d'environ 100 m, fournissant ainsi plus de details et d'information sur ces elements. Les masses intrusives comme les dykes de diabase, les roches dioritiques et monzodioritiques et lesrochesvolcaniques mafiques sont reconstituees en tant que structures de forte conductivite electrique dans les resultats d'inversion. Les roches metasedimentaires sont resistives et le mort terrain est conducteur dans la majeure partie de la region. Les donnees geophysiques et les resultats d'inversion semblent indiquer la presence de certains elements (tels que des dykes de diabase et des roches monzodioritiques) qui n'apparaissent pas encore dans certains secteurs de la carte geologique. Une comparaison de la susceptibilite obtenue des donnees EM et de la susceptibilite obtenue des donnees magnetiques au-dessus des formations de fer peut reveler l'effet d'une magnetisation remanente. [Traduit par la Redaction] Mots-cles : region du gisement Canadian Malartic, exploration pour l'or, methode d'inversion, methodes magnetiques et electromagnetiques., Introduction The Canadian Malartic Gold Mine is an open pit mine that is owned by the Canadian Malartic General Partnership, a 50/50 joint venture between Agnico Eagle Mines Ltd. (Toronto, [...]

Finishing, in most cases, is the most expensive step for manufacturing plastic parts in automotive and truck industry; being electrostatic painting is the desired approach for improved quality. For plastic parts to be painted electrostatically, a conductive primer needs to be applied first. In the case of SMC compression molded parts, in-mold coating (IMC) is the primer material of choice, as it also serves to fill the surface porosity typical in SMC parts. To make the IMC conductive, the current approach is to add carbon black (CB), which results in a black colored primer. In this research, single wall carbon nanotube (SWCNT) was evaluated, as an alternative to CB, to develop a clearer version of conductive IMC. The effect of SWCNTs on both degree of lightness and electrical conductivity was experimentally evaluated. The results indicate that a clearer and slightly more conductive coating than standard IMC can be obtained by adding 0.15 wt% SWCNTs into the base IMC resin, which results in approximately 12.5% paint saving compared to standard IMC. The processability of the modified coating was shown to be only slightly less favorable than standard coating. KEYWORDS electrostatic painting, in-Mold coating, multi-criteria optimization, paint transfer efficiency, Pareto frontier, single wall carbon nanotube, 1 | INTRODUCTION Plastics are playing an increasingly important role in the automotive and truck industry due to their lightweight and relatively low cost. It enables compliance with fuel economy [...]

This investigation was aimed to enhance the dispersibility of multi-walled carbon nanotubes (MWCNT) using sodium polystyrene sulfonate (Na-PSS) polyelectrolyte. Subsequently, electrically conducting, multi-layer thin films are prepared utilizing layer by layer assembly method with poly(vinyl alcohol) as a host matrix. The highest extent of MWCNT dispersion was observed in MWCNT:Na-PSS ratio of 1:9 (wt/wt), which was estimated from UV-Vis spectroscopic analysis. Zeta potential measurements of Na-PSS modified MWCNT dispersion showed large negative potentials ranging from -52 to -64 mV in the most stable pH range of 4 to 10, suggesting the colloidal stability is due to the long-range repulsive nature of electrostatic interactions from negatively charged sulfonate groups. Complementary molecular dynamics simulations showed that adsorption of Na-PSS imparts a large negative potential to the carbon nanotube surface, which increases with an increase in Na-PSS concentration. The multi-layer thin film of (1:9) MWCNT:Na-PSS exhibited a DC electrical conductivity of 2.96 * [10.sup.2] S/m. KEYWORDS conducting thin films, layer by layer assembly, multi-walled carbon nanotubes, poly(sodium 4-styrene sulfonate), zeta potential measurement, 1 | INTRODUCTION Carbon nanotubes (CNTs) with their high aspect ratio and an unique combination of its superior electrical, mechanical, thermal and elastic properties are considered as an ideal nanomaterial [...]

Nanostructured carbon-based polymeric nanocomposites are gaining research interest because of their cost-effectiveness, lightweight, and robust electromagnetic interference (EMI) shielding performance. Till now, it is a great challenge to design and fabricate highly scalable, cost-effective nanocomposites with superior EMI shielding performance. Herein, highly scalable EMI shielding material with tunable absorbing behaviors comprising of low-budget ketjen black (K-CB) reinforced poly(methyl methacrylate) (PMMA) nanocomposites have been prepared using simple solvent assisted solution mixing technique followed by hot compression technique. The morphological investigation revealed the homogeneous distribution of K-CB and strong interfacial interaction in PMMA matrix, which validated the strong reinforcement and other intriguing properties of the nanocomposites. The PMMA nanocomposites showed a low percolation threshold (2.79 wt%) and excellent electrical conductivity due to the formation of 3D conductive network like architecture within the polymer matrix. Specifically, the 10 wt% K-CB nanocomposite possessed a superior EMI shielding performance of about 28 dB for X-band frequency range. Further, a huge change in EMI shielding performance of PMMA nanocomposites is observed with varying thickness. The brand new K-CB decorated PMMA nanocomposites are expected to open the door for next-generation costeffective EMI shielding materials for academic and industrial applications. KEYWORDS carbon black, electrical conductivity, electromagnetic interference shielding, flexural properties, low percolation threshold, 1 | INTRODUCTION With huge development and popularization of electronic and electrical devices, humankind binds with increasingly electromagnetic (EM) radiation pollution. [1,2] As per the present scenario, it has the [...]

Composites of cobalt ferrite nanorods in a polyaniline matrix have been synthesized and characterized by electron microscopy observation, X-ray diffraction, infrared spectroscopy, thermogravimetric analysis, electrical conductivity, and DC magnetization measurements. The composites were prepared using dodecylbenzenesulphonic acid both as a particle protector and as acid media. In the magnetic experiments, hysteresis loops were observed, revealing ferromagnetism for both particles and composites. The results indicate that the magnetic properties of the particles were preserved in the composites, and on the other hand, the conductivity was almost independent on the polymer/particle ratio. These composites are new materials that show easily tunable magnetic properties, and are expected to be candidates for applications such as microwave shields., INTRODUCTION Composites formed by magnetic nanoparticles (MNPs) embedded in a conducting polymer matrix are very interesting due to the capability of combine electrical conduction with magnetic properties [1-4]. MNPs are [...]

This paper reports the study of DC electrical conductivity of films of [Se.sub.80-x][Te.sub.20][Bi.sub.x] (0 [less than or equal to] x [less than or equal to] 12) glasses prepared using physical vapor deposition method. The films were structurally characterized using X-ray diffraction (XRD) and transmission electron microscopy (TEM). TEM results indicate the formation of nanorods within the films. The electrical conductivity of the samples was studied using Keithley electrometer in the temperature range 303-373 K. The results show that conduction in these samples takes place via thermally assisted tunnelling and variable range hopping of charge carriers corresponding to higher and lower temperature ranges, respectively. Further, it was found that the conductivity increases with increase in Bi concentration in Se-Te system. This has been explained on the basis of chemically ordered network model. It was also found that nanorod formation improves the electrical conductivity of Se-Te-Bi system compared to bulk Se-Te-Bi system.Key words: glasses, nanorods, electrical conductivity, Mott's VRH model, hopping conduction.Nous etudions ici la conductivity electrique de films de verres [Se.sub.80- x][Te.sub.20][Bi.sub.x] (0 [less than or equal to] x [less than or equal to] 12), prepares par methode de deposition physique de vapeur. Les films sont caracterises par methodes CRX et MET. Les resultats MET indiquent la formation de nanotiges a l'interieur des films. La conductivity electrique est mesuree a l'aide d'un electrometre Keithley pour des temperatures de 303 a 373 K. Les resultats montrent que la conductivite dans ces echantillons se produit par effet tunnel assiste thermiquement et par mecanisme de saut a distance variable des porteurs de charge, correspondant a des domaines de plus hautes et de plus basses temperatures, respectivement. Nous trouvons egalement que la conductivite augmente avec l'augmentation de la concentration de Bi dans le compose. Ceci s'explique par le modele de reseau chimiquement ordonne. Nous trouvons egalement que la formation de nanotiges dans les films ameliore leur conductivite electrique. [Traduit par la Redaction]Mots-cles: nanotiges, conductivite electrique, modele de saut a distance variable 3D de Mott, conduction par mecanisme de sauts, verres., 1. IntroductionNanostructured semiconductors have gained significant interest in recent years due to their tunable band structure and enhanced electrical and optical properties. Nanostructured chalcogenide glasses are a new class of [...]

The need for high performance materials for use in aerospace applications is driving the search for novel structural materials. Refractory metal diborides (e.g., zirconium diboride, Zr[B.sub.2], and hafnium diboride, Hf[B.sub.2]) [...]

Novel electroactive nanocomposites were prepared by adding to a polyamide 12 (PA12) matrix different amounts (from 1 to 8 wt%) of reduced graphene oxide (rGO), and the thermo-electrical behavior of the prepared bulk materials was compared with that of the corresponding fibers. FESEM micrographs on bulk materials highlighted an evident aggregation of the rGO lamellae, proportional to the filler concentration. The presence of rGO stacks was responsible of a heavy embrittlement of the samples, with a strong reduction of the elongation at break, and of the limited electrical conductivity of the samples (about [10.sup.5] [OMEGA] x cm with a rGO amount of 4 wt%). Moreover, nanofiller addition determined an improvement of the thermal degradation resistance, associated to a slight drop of the glass transition temperature (about 7[degrees]C with a nanofiller concentration of 4 wt%) and of the crystallinity degree (up to 9% for an rGO loading of 4 wt%). The extrusion process adopted to prepare nanocomposite fibers caused a partial breakage of rGO aggregates and their progressive alignment along the drawing direction, determining thus an electrical resistivity increase with respect to the bulk samples. Therefore, the surface heating of the prepared fibers through Joule effect was possible only at elevated rGO amounts (i.e., 8 wt%). POLYM. ENG. SCI., 59:198-205, 2019., INTRODUCTION It is well known that nanofiller addition can noticeably improve the mechanical stability [1,2] and the thermal degradation resistance [3-7] of polymer matrices. Furthermore, different techniques were recently adopted [...]