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;

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;

&nbsp;

MIT World Peace University

School of Polymer Engineering

Sensor arrays capable of sensing different gases combined with a sampling system and a means of pattern classification and recognition comprise a basic system for an 'Electronic Nose' In the present work, a complete process for the fabrication of micro-cavities with sensing electrodes and volumes ranging from 2.5 to 12 nano-liters for the development of polymer gas sensors has been reported. An array of eight sensing cells in four sizes have been fabricated using SU-8 negative tone resist through UV-LIGA process developed at CEERI, Pilani. The length and width of the SU-8 cavities are: 250 × 250, 300 × 300, 500 × 500 and 500 × 600 micron and the depth of each of them was optimized to be 40 micron. These cavities filled with different polymer composites comprise the basic sensing cells for a variety of gases. The current paper presents the salient features of the fabrication process in detail and the results obtained in ethanol and methanol ambient using a polymer composite developed through dissolution of styrene and polyaniline in PMMA. A number of other composites such as Pc-Ppy, Pr-Ppy, Fc+-PPy have also been synthesized and tested for a high sensitivity in carbon monoxide.

World University root node

Engineering and Technology

Indian Journal of Pure and Applied Physics

Fabrication of MEMS composite-polymer gas sensor arrays for electronic nose

Polymer mediated growth (PMG), which forms an important method for synthesis of nanoparticles, has one of the ions bound by polymer matrix while the other is allowed to diffuse and react to form desired compound. The exact role of ionic diffusion in the formation of nanoparticles has been investigated by taking specific case studies. Typically calcium carbonate, calcium phosphate and calcium sulfate have been formed in nano-size by PMG route using polyacrylamide gel. The extent of cross-linking of the polymer matrix in the formation of gel, affects the diffusivity of ions into polymer matrix and the size of particles formed. The rates of diffusion for different extents of cross-linking of polymer are estimated during the synthesis of nanoparticles using Fick's law. The inter-correlation between the particle size formation and the diffusion length has been clearly brought out in these studies. © 2007 Elsevier B.V. All rights reserved.

Materials Chemistry and Physics

Role of ionic diffusion in polymer gel mediated growth (PMG) technique for the synthesis of nanoparticulate fillers

High-temperature thermoplastic-graphite composites are prepared using polyphenylene sulfide (PPS) and polyether sulfone (PES) containing natural graphite powder. All samples are prepared by high pressure compaction and heating to high temperatures. The effect of a third additional conducting component on the electrical resistance of these composites is studied. A low resistance of the order of 0.1 Ω can be obtained even for a graphite concentration of 50% by addition of the third component. The effect of a mixing/blending technique on the anisotropy of conductivity is investigated. Solution blending of PES with graphite leads to lower anisotropy values than powder mixing and compression moulding. The samples when exposed continuously to a working temperature of 100 °C give a small but significant reduction in electrical resistance. X-ray diffraction studies on composites prepared by different techniques indicate that there is restructuring and crystallite re-orientation of the graphite phase in the samples. A large reduction in the crystallite size is observed for samples prepared by solution blending while re-orientation occurs after heat treatment. The changes in electrical properties can be correlated with these structural transformations in the composites. © 2006 Elsevier B.V. All rights reserved.

Journal of Power Sources

High-temperature, polymer–graphite hybrid composites for bipolar plates: Effect of processing conditions on electrical properties

<a href="https://www.sciencedirect.com/topics/engineering/polyvinylidene-fluoride">Polyvinylidene fluoride</a> (PVDF)–barium titanate (BaTiO3)–polyaniline (PANI) <a href="https://www.sciencedirect.com/topics/physics-and-astronomy/hybrid-composites">hybrid composites</a> were prepared by conventional powder processing technique which exhibited remarkably high piezo-sensitivity. The effect of poling of these semi-insulating composites on their piezo-response was quite dramatic. Sensitivity factors of 3000 could be achieved for even small poling voltages as low as 180&nbsp;V/mm. The <a href="https://www.sciencedirect.com/topics/engineering/synergistic-effect">synergistic effect</a> was obtained only when all three components, viz. PANI, PVDF and BaTiO3 were present at certain proportion below <a href="https://www.sciencedirect.com/topics/engineering/percolation-threshold">percolation threshold</a> in the composite. The results have been explained on the basis of charge storage in the piezo components due to the high fields generated, even for low external applied field, at the inter-granular sites between the semi-conducting <a href="https://www.sciencedirect.com/topics/engineering/polyaniline">polyaniline</a> <a href="https://www.sciencedirect.com/topics/engineering/dispersed-phase">phase dispersed</a> in the <a href="https://www.sciencedirect.com/topics/engineering/insulating-matrix">insulating matrix</a>.

Sensors and Actuators A: Physical

Novel polyaniline/PVDF/BaTiO3 hybrid composites with high piezo-sensitivity

The optical properties of substituted thiophenes with diverse structures have been analysed using molecular orbital calculations in order to understand the structure-property relations. Based on theoretical predictions, synthesis of some model compounds has been attempted. The experimentally obtained optical properties are in close agreement with the theoretically obtained results. © 2005 Elsevier B.V. All rights reserved.

Computational Materials Science

Structure and properties of polythiophene containing hetero aromatic side chains

Design, synthesis and characterization have been carried out on poly(thiophene)s bearing electron-deficient side chains. The influence of structure on the optical characteristics was studied in detail using molecular orbital calculations. The model compounds have been synthesized and their photoabsorption, photo- and electro-emission characteristics were studied. The results indicate that substituting appropriate heteroaromatic groups to the thiophene chain can enhance electro-emission, even with a single emissive layer, in PLEDs. © The Royal Society of Chemistry 2006.

Fulltext

Journal of Materials Chemistry

Poly(thiophenes) functionalised with thiazole heterocycles as electroluminescent polymers

Plastics have become a major factor in modern life and the massive volume of plastics in use has a significant effect on the environment. Major efforts are underway to reduce the impact of plastics on the environment and to make them more eco-friendly. Such efforts include the use of bio-materials instead of nonrenewable resources such as petroleum for manufacturing polymers. There are also studies which are aimed at reducing the impact of discarded plastic products on air and water supplies, as well as on flora, fauna, and landfills. © 2006 SAGE Publications.

School of Chemical Engineering

Journal of Plastic Film and Sheeting

Studies toward producing eco-friendly plastics

The response of a bi-layer conducting polymer-based actuator has been studied with respect to various parameters such as backing layer thickness, backing layer modulus, applied voltage, etc. The bending angles for the bi-layer actuators made by depositing, conducting polypyrrole (PPy) films on backing layers using LDPE/LLDPE, SBS, Hytrel, PP, PET materials have been compared. The response of the bi-layer actuators indicates that there is optimum for the backing layer thickness as well as its material modulus together with the thickness of the conducting polymer at which the maximum bending is observed. Other geometrical parameters such as a length to width ratio also influence the response of these actuators and have to be chosen properly for the best actuator performance. © 2005 Elsevier B.V. All rights reserved.

Sensors and Actuators, B: Chemical

Response characteristics of conducting polypyrrole bi-layer actuators: Role of backing layer polymer

Molecular orbital calculations have been performed on thiophene oligomers bearing heterocyclic substituents at the third position in order to understand the interplay of effects such as the nature of substituent, skeletal substitution pattern, heteroatom identity, etc. on electronic transitions. The geometry optimization was carried out using the semiempirical AMI method, and the electronic transitions predicted for the oligomers were extrapolated for polymers using an oligomeric approach. The experimentally determined optical transitions were found to follow the predicted trend of electronic transitions of monomers and polymers. © 2006 American Chemical Society.

Journal of Physical Chemistry B

Molecular orbital calculations on polythiophenes containing heterocyclic substituents: Effect of structure on electronic transitions

Hybrid composite coatings containing zinc oxide (ZnO) and polyaniline (PANI) as nano-additives dispersions were prepared with poly(vinyl acetate) (PVAc) as the major matrix. The steel plates dip-coated with these formulations were tested for corrosion protection by immersion in saline water over long periods. The Tafel plots for the determination of open circuit potential (OCP) and corrosion current (Icorr) were recorded. The coatings containing both ZnO and PANI showed improved corrosion resistance as compared to the single component coating. The Icorr values of PVAc-ZnO-PANI are found to be two-order magnitude lower than that of PVAc and PVAc-ZnO coatings. The results are explained on the basis of enhancement in barrier properties due to nano-particulate additives in PVAc-ZnO-PANI film together with the redox behaviour of PANI and protective oxide layer formation near the substrate. © 2006 Elsevier B.V. All rights reserved.