<p>MIT-World Peace University (MIT-WPU) is a top educational institute located in Pune, India. It is recognized within&nbsp;UGC under Government of Maharashtra Act No. XXXV 2017.&nbsp;</p>

<p>It is part of the MIT group of institutions (established in 1983) which covers 10+ campuses across India and has more than 50,000+ students enrolled across various disciplines at a given point of time. The institute houses 15 schools ranging from Engineering &amp; Technology, Design, Pharmacy, Commerce, Governance among others. It offers undergraduate, postgraduate and PhD programs among different disciplines.&nbsp;</p>

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MIT World Peace University

School of Polymer Engineering

Nano-particles of γ-Fe2O3 were synthesized by reacting polyethylene oxide-FeCl3 complex with NH4OH. These were characterized by X-ray diffraction (XRD), scanning electron miscroscopy (SEM), selected area electron diffraction (SAED) and transmision electron microscopy (TEM). The average particle size was found to be 10 nm, as determined from the line broadening of the main XRD peak. The crystalline phase was a spinel-type tetragonal structure, which was confirmed from the electron diffraction pattern. The zero field cooled magnetization of samples with varying γ-Fe2O3 content as a function of temperature was measured using a vibrating sample magnetometer. The magnetization curves show a peak at low temperature (15 K) corresponding to the blocking temperature TB. The value of TB was found to decrease with decreasing particle size. The magnetization measurements with respect to field at 5 and 170 K confirmed the transition from superparamagnetic to spin-glass state at TB, as evidenced from the remanence and hysteresis. These results can be explained on the basis of Néel's theory of superparamagnetism as applied to nano-particles. © 2001 Elsevier Science Ltd.

Engineering and Technology

World University root node

Polyhedron

Polymer-mediated synthesis of γ-Fe2O3 nano-particles

Polypyrrole films containing phthalocyanine were deposited by direct electrochemical deposition method using mixed solvent system (NMP:H2O) with H2SO4 (0.1 M). The films obtained were characterized by conventional techniques such as FT-IR and UV-VIS, which confirmed the incorporation of phthalocyanine. The presence of Cu(2p) core level peak in the ESCA studies also confirmed the incorporation of phthalocyanine in these films. The electrical conductivity was found to increase with the increase of phthalocyanine concentration in the electrolyte. Even for a moderate increase of CuPc (from 1.0 to 2.0 mol%) in the PPy films, there is a drop in activation energy from 0.133 to 0.08 eV. Sensitivity measurements show that the CuPc containing PPy films are selectively more sensitive to the nitrogen dioxide vapours. The C-V studies carried out on these films under illumination show that the photochemical response in electrochemical mode increases due to the presence of phthalocyanine. The cathodic peak at -700 mV, which is associated with the phthalocyanine, becomes prominent under illumination due to photogenerated carriers. © 2001 Elsevier Science B.V.

Materials Letters

Electrical properties of conducting polypyrrole films functionalized with phthalocyanine

The electrocatalytic property of the conducting polypyrrole (PPy) films doped with palladium chloride and irradiated with heavy ion beams was studied for methanol oxidation. The PPy films were electropolymerized on gold film coated glass plate electrodes, subsequently doped with different amounts of PdCl2 and then irradiated with 120 MeV, Au+ ions at a dose of 1012ions/cm2. The cyclic voltammograms (CVs) of these samples for methanol oxidation in 0.1 M HClO4 showed a four times increase in the anodic current as compared to the un-irradiated ones. These improvements in the electrocatalytic activity by ion beam irradiation could be associated with better complex formation between the dopant and conducting polymer matrix which was confirmed by the X-ray photoelectron spectroscopy (XPS) studies. © 2001 Elsevier Science B.V.

Chemical Physics Letters

Electrocatalytic properties of the ion beam irradiated conducting polypyrrole

Our experimental observations show that certain dyes when incorporated in solid polymer electrolytes (SPE) can serve as an excellent candidates for optical humidity sensing. Crystal violet (CV) have been incorporated in poly(vinyl alcohol) (PVA)/H3PO4, which is known to be a SPE and a good proton conductor. Films of PVA/H3PO4 containing CV dye have been studied for use in optical humidity sensing and the interesting results have been discussed here in this paper. We have also tried to give a mechanism for the changes observed in the optical properties of such films by the variation of humidity. © 2001 Published by Elsevier Science B.V.

Organic Electronics

Novel dye + solid polymer electrolyte material for optical humidity sensing

The mechanical properties viz. impact and tensile modulus of hybrid composites of PP/SBS/glass in the composition range 0-40 wt% of glass fibers (GF) were studied. Both impact and tensile modulus increased with respect to glass content at a certain composition of the blend. Synergistic effects were seen in the value of elongation and toughness at a certain composition of the glass content. The above findings could be associated with the high aspect ratio and nucleation ability of GF together with good interfacial adhesion between the GF and SBS, rather than the PP matrix. These have been supported by the investigations on structures and morphologies of the hybrid composites.

Polymer Composites

Structure and properties of PP/SBS/glass fiber hybrid composites. Part II: Property measurement

<p>The structure and morphology in the meta-nitroaniline (MNA) dispersed poly(methyl methacrylate) (PMMA) guest/host system was investigated with respect to composition and different techniques of crystallization. Large changes in the intensities of various X-ray diffraction peaks were observed for both solution grown (SC) and melt crystallized (MC) MNA/PMMA composite films. However, in the former case, the peak corresponding to (060) reflection had maximum intensity, while in the latter, the peak corresponding to (112) reflection was most prominent. At low concentrations, the films appeared to be amorphous and transparent, but electron diffraction studies revealed small ordered domains. Both solution and melt grown MNA/PMMA films contained two types of crystallites having different structures: one having the original orthorhombic structure (a = 6.51 Å, b = 19.35 Å, c = 5.07 Å) of bulk MNA, while the other crystallized in new monoclinic phase with a = 13.0 Å, b = 19.35 Å, c = 10.15 Å, and β = 64°. The presence of the new structure that formed could be due to a formation of complex between PMMA and MNA. This complex formation and new structure was further confirmed by differential scanning calorimeter (DSC) and infrared analysis (IR). © 2001 John Wiley &amp; Sons, Inc. J Appl Polym Sci 80: 1547–1557, 2001</p><h2>&nbsp;</h2>

Journal of Applied Polymer Science

Polymer mediated growth and morphology in MNA/PMMA guest/host microdispersed composites

The thermal degradation/stability of poly(o-phenitidine) doped with different sulfonic acids was investigated with the help of thermogravimetric analysis coupled with mass spectrometer. Thermal decomposition behaviour was found to depend on the nature of dopant ion and the thermal stability was in the order of DBSA > CSA > PTSA. The dopant ion was found to dissociate prior to the main chain scission. These findings could be explained on the basis of strong coupling/complexation between the conducting polymer and the dopant as well as the stability of the individual dopant species. © 2001 Elsevier Science Ltd.

Polymer Degradation and Stability

Effect of dopant ions on thermal stability of conducting poly(o-phenitidine)

The structure development, crystallization behavior and morphology were studied in hybrid composites made with polypropylene/styrene-butadiene-styrene (PP/SBS) containing glass fibers (GF). The techniques applied include optical polarizing microscopy, X-ray diffraction and scanning electron microscopy (SEM). The isothermal crystallization studies of PP/SBS/GF revealed that SBS as well as GF could act as good nucleating agents for PP. However, the nucleation efficiency of GF is much higher than that of the SBS. At high concentrations of SBS (> 30%), the crystallization rate decreases even in the presence of GF. This was attributed to the strong bonding between SBS and glass, giving rise to an intermediate layer of SBS between PP and GF, which was confirmed from the SEM of the fractured morphology of the injection molded hybrid composite. The orientation of GF was observed in the injection molded samples for certain compositions, and this was accompanied by an increase of intensities of particular diffraction peaks in the XRD.

Structure and properties of PP/SBS/glass fiber hybrid composites. Part I: Crystallization behavior and morphology

The effect of small concentration of dispersed prussian blue (PB) [in solid polymer electrolyte viz polyvinyl alcohol (PVA) with phosphoric acid] on the photocurrents were studied (in wet state and in dry state of solid polymer electrolyte) in solid state photocells fabricated using conducting polypyrrole (PPy). These exhibit good photoresponse to visible light: photocurrents being 20 to 25 times greater than the dark currents depending upon the concentration of the sensitizer. The current-voltage (I-V) characteristics in such cells reveals that the charge transport is mainly governed by the space charge effects and the sensitization effects are due to the lowering of the potential barrier formed at the polypyrrole (PPy)/polyvinyl alcohol (PVA) interface under photoexcitation. Also, sensitization effects were studied in the wet state and in dry state of solid polymer electrolyte (PVA). It has been observed that the moisture content in the solid polymer electrolyte reduces the photosensitivity factor (S = Il/Id, where Il is the light current and Id is the dark current), since it increases the ionic conductivity in the solid polymer electrolyte thereby increasing the dark current values which results in overall decrease in the photosensitivity factor (S). The importance of the other factors such as dye concentration, dye aggregation etc. have been explained on the basis of the experimental observations. The sensitization effects are explained on the basis of the energy band diagram of the materials forming the photocells.

Synthetic Metals

Effect of moisture (in solid polymer electrolyte) on the photosensitivity of conducting polypyrrole sensitized by prussian blue in solid-state photocells

The electrochromic response of conducting polypyrrole (PPy)/Prussian blue (PB) and conducting polyaniline (PANI)/Prussian blue (PB) composite films has been studied in different electrolytes such as KCl, LiClO4, K2SO4, KNO3, KI/I2, etc. by depositing the PB films on top of the conducting PPy and PANI films-all prepared by electrochemical methods. The results show that the use of PB on PPy and PANI not only yields high contrast but also extends the electrochromic response to a wider region of the visible spectrum, thus working as a sensitizer for improving the electrochromic response of the conducting PPy and PANI. These electrochromic films have been characterized by other physicochemical characterization techniques such as cyclic voltammetry, SEM, XPS, XRD, etc. The electrochromic behaviour of the PPy/PB composite system has been described in detail. Electrochromic display devices using solid polymer electrolytes, which are directly useful for commerical production of such devices are currently under study.