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In this study, the self-standing membranes of polyaniline (PANI) containing N,N′-Dimethyl propylene urea – were prepared by solution cast method followed by protonation with concentrated hydrochloric acid. The secondary amine i.e. heptamethyleneimine was used as a gel inhibitor, and to stabilize the PANI in N,N′-dimethyl propylene urea solution. Different physicochemical techniques such as X-ray Diffractometry, Fourier transform infrared spectroscopy, and scanning electron microscopy were used for the characterizations of membranes. X-ray study shows that crystallinity of protonated PANI membrane was higher than that of non-protonated membrane. The non-protonated PANI membrane had only short fibers. However, protonated membrane also had long fibers/or bunch of fibers along with short fibers. Secondary amines with moderate or strong basicity, reduce most of the quinoid ring to form a ring-substituted material because of which materials conjugated structure was degraded. The DC electrical conductivities of the membranes were evaluated with an electrometer. It has been observed that protonated PANI membrane was electrically more conducting as compared to non-protonated membrane. The electrical conductivity of non-protonated and protonated PANI membranes upto 4 V was 5.95 μS/cm and 6.73 μS/cm, respectively and beyond that, it increased to 7.29 μS/cm and 8.45 μS/cm. The protonated PANI membranes with higher electrical conductivity could be useful for the hydrogen fuel cell application.

The aim of the work is to develop a low-cost cast iron having comparable corrosion resistance with that of Ni-Resist cast iron but free from graphitic corrosion. In experimental alloys, austenitic matrix was found in both as-cast and heat treated conditions. The volume fraction of austenite also increased with increase of heat treatment temperature and time at temperature. X-ray diffractometry, energy dispersive analysis and optical microscopy were employed to investigate the microstructural features. Hardness testing and corrosion study were carried out. The corrosion rates were in the proximity of those of Ni-Resist irons especially on heat treatment at higher temperatures.

Activated carbon (AC) supported Fe3O4 nanoparticle-based composites (CFFs) have been prepared by mixing AC with a Fe3O4 ferrofluid followed by drying. These composites display a unique combination of electrical and magnetic properties along with nanoporosity. The structural, morphological and magnetic properties of the synthesized CFF composites have been characterized by XRD, SEM, TEM, VSM and TGA. The water purification capability has been demonstrated using methyl orange (MO) dye as an impurity. The porosity and magnetic properties enable fast adsorption of MO and magnetic separation of MO adsorbed OFF particles, respectively. In addition to water purification, these multifunctional CFFs may also find promising applications in catalyst separation, bioreactors, and for shielding electromagnetic interference in the microwave frequency range.

The purpose of this work is to study the influence of heat treatment on the corrosion resistance of a newly developed white cast iron, basically suitable for corrosion- and wear-resistant applications, and to attain a microstructure that is most suitable from the corrosion resistance point of view. The composition was selected with an aim to have austenitic matrix both in as-cast and heat-treated conditions. The difference in electrochemical potential between austenite and carbide is less in comparison to that between austenite and graphite. Additionally, graphitic corrosion which is frequently encountered in gray cast irons is absent in white cast irons. These basic facts encouraged us to undertake this work. Optical metallography, hardness testing, X-ray diffractometry, and SEM–EDX techniques were employed to identify the phases present in the as-cast and heat-treated specimens of the investigated alloy and to correlate microstructure with corrosion resistance and hardness. Corrosion testing was carried out in 5 pct NaCl solution (approximate chloride content of sea water) using the weight loss method. In the investigated alloy, austenite was retained the in as-cast and heat-treated conditions. The same was confirmed by X-ray and EDX analysis. The stability and volume fraction of austenite increased with an increase of heat-treated temperature/time with a simultaneous decrease in the volume fraction of massive carbides. The decrease in volume fraction of massive carbides resulted in the availability of alloying elements. These alloying elements, on increasing the heat treatment temperature or increasing the soaking period at certain temperatures, get dissolved in austenite. As a consequence, austenite gets enriched as well as becomes more stable. On cooling from lower soaking period/temperature, enriched austenite decomposes to lesser enriched austenite and to a dispersed phase due to decreasing solid solubility of alloying elements with decreasing temperature. The dispersed second phase precipitated from the austenite adversely influenced corrosion resistance due to unfavorable morphology and enhanced galvanic action. Corrosion rate and hardness were found to decrease with an increase in heat treatment temperatures/soaking periods. It was essentially due to the increase in the volume fraction and stability of the austenitic matrix and favorable morphology of the second phase (carbides). The corrosion resistance of the investigated alloy, heat treated at 1223 K (950 °C) for 8 hours, was comparable to that of Ni-Resist iron. Thus, a microstructure comprising austenite and nearly spherical and finer carbides is the most appropriate from a corrosion point of view. Fortunately, the literature reveals that the same microstructure is also well suited from a wear point of view. It confirms that this investigated alloy will be suitable for corrosive-wear applications.

An attempt is taken to develop a flexible and light weight polycarbonate-based nanocomposite system which could be successfully used as a dielectric material below percolation and as conducting material beyond percolation. The nanocomposite system has been prepared by solution mixing method in which few layer graphene was incorporated as conductive filler. X-ray diffractometry, Raman spectroscopy, transmission electron microscopy, scanning electron microscopy techniques were employed for characterization studies. The dielectric constant and conductivity were evaluated using precision impedance analyzer. Percolation threshold has been observed to occur at 3.5 wt % of few layer graphene. Dielectric constant of the nanocomposite system, in the smearing region, has been found to increase from ∼3.3 (without filler) to ∼70 (at 5 wt % FLG) with a dissipation factor of 0.07. The conductivity of the system was increased from 10−9 S/cm without FLG to 10−2 S/cm with 7 wt % of few layer graphene. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42443.

Polycarbonate (PC)/Lead Zirconate Titanate (PZT) composites were prepared using solution mixing method followed by hot pressing. The volume fraction of PZT particles was varied from 0 to 27.5%. SEM showed good dispersion of PZT in the PC matrix. XRD confirmed the perovskite structure of PZT and amorphous structure of polycarbonate. The dielectric constant of the composites measured at 1 kHz, increased ∼3.5-fold compared with pure PC. The modified Lichtenecker equation agreed well with the experimental data. There was no dispersion in the dielectric constant of the composites for the frequency range of 1 kHz to 10 MHz. However, at frequencies higher than 10 MHz significant drop in dielectric constant was observed. The dissipation factor of the composites was found below 0.02. However, above 1 MHz, an abrupt increment in the dissipation factor was observed. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39913.

Three-phase polycarbonate (PC) matrix nanocomposites are prepared using the solution method. One of the nanocomposite fillers is dielectric and the other is conducting. Lead zirconate titanate (PZT) is used as the dielectric filler. The conducting fillers, nano-Cu and multi-walled carbon nanotubes (MWCNTs), are used to make two different nanocomposites, MWCNT–PZT–PC and Cu–PZT–PC. The prepared nanocomposites are characterized using density measurement, x-ray diffractometry, scanning electron microscopy, energy dispersive x-ray spectroscopy, and differential scanning calorimetry. Percolation is absent in both three-phase nanocomposites within the study's concentration window of conducting fillers. The dielectric properties of the nanocomposites are evaluated using a precision impedance analyser. The dielectric constant of the Cu–PZT–PC nanocomposite increases to 14 (a dissipation factor of 0.17), whereas in the case of the MWCNT–PZT–PC nanocomposite it increases to 8.5 (a dissipation factor of 0.002). The melting point of both nanocomposites decreases with respect to the control PC. The frequency (1 kHz to 1 MHz) and temperature (room temperature to 200 °C) dependence of the dielectric constant and dissipation factor are examined. For the Cu–PZT–PC nanocomposites, the dielectric constant decreases with increasing frequency, whereas in the case of the MWCNT–PZT–PC nanocomposites the dielectric constant is almost constant. The dielectric constant and dissipation factor exhibit a slight temperature dependence.