The Front End in Anti-Electrostatic Discharge for Product Innovation Development:Polycarbonate/graphene Composite

Abstract:The conceptualization of new polymer compounding, for use in anti-electrostatic product innovation development, consists of five sub-phases which include; finding market demands and potential users, conducting preliminary scientific experiment so as to achieve the best possible compound recipes, conducting an upscale of the compound recipes for industrial prospect, assessing technology acceptance using technology acceptance methods (TAM) and, finally assessing a potential for business commercialization. Some key activities were studied in the front end research, for example, literature reviews, the methodologies of quantitative performed in front end research findings about market demands and capabilities, polymeric composites laboratory testing for finding the types and dosage amounts of graphene to be administered. In addition, the product concepts were frequently developed in parallel that require specifications of the physical, conductive and structural properties. These findings have implications for increasing the success and the qualities of front end efforts for composites of excellence

Gas Sensors Based on Electrospun Nanofibers

Nanofibers fabricated via electrospinning have specific surface approximately one to two orders of the magnitude larger than flat films, making them excellent candidates for potential applications in sensors. This review is an attempt to give an overview on gas sensors using electrospun nanofibers comprising polyelectrolytes, conducting polymer composites, and semiconductors based on various sensing techniques such as acoustic wave, resistive, photoelectric, and optical techniques. The results of sensing experiments indicate that the nanofiber-based sensors showed much higher sensitivity and quicker responses to target gases, compared with sensors based on flat films

Electrical Conductivity of Electrospun Polyaniline and Polyaniline-Blend Fibers and Mats

Submicrometer fibers of polyaniline (PAni) doped with (+)-camphor-10-sulfonic acid (HCSA) and blended with poly(methyl methacrylate) (PMMA) or poly(ethylene oxide) were electrospun over a range of compositions. Continuous, pure PAni fibers doped with HCSA were also produced by coaxial electrospinning and subsequent removal of the PMMA shell polymer. The electrical conductivities of both the fibers and the mats were characterized. The electrical conductivities of the fibers were found to increase exponentially with the weight percent of doped PAni in the fibers, with values as high as 50 ± 30 S/cm for as-electrospun fibers of 100% doped PAni and as high as 130 ± 40 S/cm upon further solid state drawing. These high electrical conductivities are attributed to the enhanced molecular orientation arising from extensional deformation in the electrospinning process and afterward during solid state drawing. A model is proposed that permits the calculation of mat conductivity as a function of fiber conductivity, mat porosity, and fiber orientation distribution; the results agree quantitatively with the independently measured mat conductivities.United States. Army Research Office (Institute for Soldier Nanotechnologies, Contract ARO W911NF-07-D- 0004

Nanocomposite electrospun nanofiber membranes for environmental remediation

Rapid worldwide industrialization and population growth is going to lead to an extensive environmental pollution. Therefore, so many people are currently suffering from the water shortage induced by the respective pollution, as well as poor air quality and a huge fund is wasted in the world each year due to the relevant problems. Environmental remediation necessitates implementation of novel materials and technologies, which are cost and energy efficient. Nanomaterials, with their unique chemical and physical properties, are an optimum solution. Accordingly, there is a strong motivation in seeking nano-based approaches for alleviation of environmental problems in an energy efficient, thereby, inexpensive manner. Thanks to a high porosity and surface area presenting an extraordinary permeability (thereby an energy efficiency) and selectivity, respectively, nanofibrous membranes are a desirable candidate. Their functionality and applicability is even promoted when adopting a nanocomposite strategy. In this case, specific nanofillers, such as metal oxides, carbon nanotubes, precious metals, and smart biological agents, are incorporated either during electrospinning or in the post-processing. Moreover, to meet operational requirements, e.g., to enhance mechanical stability, decrease of pressure drop, etc., nanofibrous membranes are backed by a microfibrous non-woven forming a hybrid membrane. The novel generation of nanocomposite/hybrid nanofibrous membranes can perform extraordinarily well in environmental remediation and control. This reality justifies authoring of this review paper

Electrospun polyacrylonitrile-based carbon nanofibers and their silver modifications: surface morphologies and properties

Polyacrylonitrile (PAN)-based carbon nanofibers (CNFs) were prepared via the electrospinning process. Silver (Ag) modifications of these CNFs were carried out using in-situ Ag reaction as well as Ag coating methods. Ag modified CNFs from both methods yielded higher electrical conductivity than the neat CNFs due to the synergetic effect from the Ag nanoparticles. The effects of fiber diameter, fiber aspect ratio and the interconnecting network nature of the non-woven fiber mat on the electrical and thermal decompositional properties of as-prepared fibers were also investigated. The structural characterizations of as-prepared fibers were performed using SEM, Raman spectroscopy, WAXD, and TGA methods

Nanocomposites of epoxy with electrospun carbon nanofibers: mechanical behavior

Electrospun polyacrylonitrile (PAN) fiber precursor-based carbon nanofiber (CNF) mats were produced and impregnated with epoxy resin. The mechanical properties of as-prepared nanofibers in the mat and short fiber filled epoxy nanocomposite forms were determined to demonstrate the effect of fiber aspect ratio on those properties. The experimental results reveal that epoxy nanocomposites containing electrospun carbon nanofibers (ECNF) with high fiber aspect ratio in the non-woven mat form yield better mechanical properties than those filled with short ECNFs. The ECNF mat in epoxy nanocomposites provides better homogeneity and easier preparation than short ECNFs. Mechanical properties of ECNF mat-epoxy nanocomposites, which were obtained using tensile and flexural tests, such as stiffness, increased, while toughness and flexural strength decreased, compared with the neat epoxy resin. Dynamic mechanical analysis results showed higher modulus for ECNF mat-epoxy nanocomposites, compared with those for neat epoxy resin and short ECNF-epoxy nanocomposites. The ECNF-epoxy nanocomposites had higher storage and Young\u27s moduli with 1.23, 3.56 and 9.28 wt% ECNF mat loadings for the storage modulus and 0.98, 2.06% ECNF mat loadings for Young\u27s modulus, even though the glass transition temperature (Tg), values dropped at all these extents of ECNF mat contents when compared with the neat epoxy resin

Nickel Nanofibers Manufactured via Sol-Gel and Electrospinning Processes for Electrically Conductive Adhesive Applications

The electrospun fibers of poly(vinyl pyrrolidone) (PVP)-nickel acetate (Ni(CH3COO)2·4H2O) composite were successfully prepared by using sol-gel processing and electrospinning technique. Nickel oxide (NiO) nanofibers were obtained afterwards by high temperature calcinations of the precursor fibers, PVP/Ni acetate composite nanofibers, at 700 °C for 10 h. Following with the reduction of NiO nanofibers at 400 °C using hydrogen gas (H2) under inert atmosphere, the metallic nickel (Ni) nanofibers were subsequently produced. In addition, as-prepared Ni nanofibers were chemically coated with silver (Ag) nanoparticles to enhance their electrical property and prevent the surface oxidation. The characteristics of as-prepared fibers, such as surface morphology, fiber diameters, purity, the amount of NiO nanofibers, and metal crystallinity, were determined using a scanning electron microscope (SEM), a Fourier transform infrared spectrometer (FT-IR), a thermogravimetric analyzer (TGA), and a wide-angle x-ray diffractometer (WAXD). The volume resistivity of epoxy nanocomposite filled with Ag-coated short Ni nanofibers was lower than the one containing short Ni nanofibers with no coating due to the synergetic effect of Ag nanoparticles created during the coating process. We also demonstrated that the volume resistivity of epoxy nanocomposite filled with Ni nanofibers could be dramatically decreased by using Ni nanofibers in the non-woven mat form due to their small fiber diameter and high fiber aspect ratio, which yield a high specific surface area, and high interconnecting network