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;

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MIT World Peace University

Engineering and Technology

Vapour phase polymerization of pyrrole on crystalline poly(ethylene oxide) (PEO) complexes gives ordered structure conforming to orthorhombic configuration with lattice parameters of&nbsp;<math xmlns="http://www.w3.org/1998/Math/MathML"><mtext>a = 6.11</mtext><mtext>A</mtext><mtext>̊</mtext><mtext>, b = 7.19</mtext><mtext>A</mtext><mtext>̊</mtext><mtext>and</mtext><mtext>c = 16.31</mtext><mtext>A</mtext><mtext>̊</mtext></math>. The detailed analysis of these films has been carried out by wide angle X-ray diffraction and X-ray photoelectron spectroscopy. A strong influence of the crystalline substrate is seen in the molecular ordering of the polypyrrole grown on them which can be explained on the basis of lattice mismatch theory. The angular dependence of the C(1s) and N(1s) core level spectra together with their variation with polymerization time suggests a bulk-initiated growth rather than a surface one.

School of Polymer Engineering

World University root node

Synthetic Metals

Polypyrrole growth on crystalline PEO complexes: characterization by WAXD and XPS

Polycarbonate obtained by solid state polycondensation (SSP) crystallizes in an orthorhombic configuration with a = 12.1 A ̊, b = 10.1 A ̊ and c = 22.0 A ̊. Its morphology is of non-spherulitic lamellar type, while that of melt or solution crystallized commercial polycarbonate is distinctly spherulitic. These changes in crystalline structure and morphology can be explained, in the present case, on the basis of restricted mobility of the chains and the crystal growth in an extended chain configuration during the SSP step. © 1994.

Polymer

Structure and morphology of polycarbonate synthesized by solid state polycondensation

Conducting thermoplastic elastomer blends have been synthesised by deposition of polypyrrole in styrene–butadiene–styrene (SBS) block copolymers containing various amounts of ferric chloride (FeCl3). These blends have phasesegregated morphology with preferenatial deposition of polypyrrole in one of the domains as confirmed by structural investigations using optical microscopy, X‐ray diffraction and infrared spectroscopy. The electrical resistivity (ρ) for these blends shows a sharp transition in the region of 273 K and is sensitive to small mechanical deformations both in compressions and extension modes. The dependence of ρ on mechanical stress (P) follows a power law of the type ρ ∝ Pn, where n has a value between 3 and 4. These various findings have been explained on the basis of a phase‐segregated morphology having highly conducting domains separated by a semiconducting/insulating matrix, together with non‐linear conduction processes for charge transport in such heterogeneous materials. © 1994 Society of Chemical Industry

Polymer International

Structure and electrical properties of polypyrrole–thermoplastic elastomer blends

The “in situ” formation of cadmium sulphide in a polyethylene oxide matrix has been studied starting with its complex with cadmium chloride. It has been found that the complex crystallizes in orthorhombic configuration with lattice parameters of a = 8.42 Å, b = 15.39 Å and c = 18.49 Å, and that its morphology is spherulitic. At high concentrations (&gt;1:4 per monomer), the added salt gets excluded out of the spherulites and deposits in the interspherulitic regions. The cadmium sulphide formed from such a complex has mixed α and β phases and its crystallite/particle size depends on the initial concentration of the cadmium chloride.

Journal of Crystal Growth

Polymer induced crystallization III. PEO-CdCl2 and in situ formation of PEO-CdS composite

A high piezoresistive effect ( Δp po = 102 kg-1cm-2) has been observed in semiconducting polyvinylidene fluoride as well as polyphenylene sulfide composites containing metallic fillers. The nonlinear current-voltage characteristics conforming to the space charge limited conduction mechanism present at the interparticulate region can give rise to the observed high sensitivity of resistance to external pressure. The results predicted by this model have been confirmed by the experimental findings. © 1994.

Materials Letters

High piezoresistivity in conducting polymer composites

Growth of polypyrrole (PPy) on crystalline poly(ethylene oxide)-ferric chloride complexes has been investigated by X-ray diffraction, optical and scanning electron microscopy. PPy deposited on such crystalline substrates develops ordered structure conforming to orthorhombic configuration with lattice parameters of a=6.11, b=7.19 and c=16.31 A ̊, which has similarity to the substrate crystallites. Preferential nucleation of PPy is seen on these substrates especially when these are oriented into fibre form. No such order is observed when amorphous polymer substrates with FeCl3 are used for PPy deposition. The electrical conductivity σ depends on FeCl3 concentration c as a power law of the type σ∞c5 and has a minimum activation energy of 0.09 eV at a molar ratio of about 1:5. The various results are in keeping with the structured growth of PPy which is strongly influenced by the crystalline order in the substrate. © 1993.

Structure development and electrical properties of polypyrrole deposited on poly(ethylene oxide) complexes

The cure monitoring of cyanoacrylate resin using a dielectric technique shows that in addition to the usual fast anionic polymerization step, there may be a secondary process involved over longer time scales. Two peaks are distinctly observed in the isothermal curing curves, and from the position of these at various temperatures, the activation energies of 0.4 eV and 0.17 eV could be derived. In cured cyanoacrylate resin, three relaxations were observed, viz., α, β, and γ, occurring at 152°c, 87°c, and 47°c, respectively (for 1 KHz measuring frequency), with activation energies of 1.3 eV, 0.56 eV, and 0.4 eV, respectively. The various results have been explained on the basis of secondary bond formation through the nitrile group, for which some evidence could be obtained from the infrared absorption spectra.

Polymer Engineering & Science

Dielectric monitoring of the curing process in cyanoacrylate resin

This study evaluates the role of intraocular lens exchange procedures in the management of major implant-related complications. Medical records of 30 patients undergoing intraocular lens exchange at the Leeds General Infirmary from 1 January 1984 to 30 November 1991 were reviewed. Details of their primary implantation surgery, intervening ophthalmic history, lens exchange surgery and outcome were analysed. Follow-up ranged from 3 to 210 weeks. Seventy-six per cent of cases achieved final visual acuity of 6/12 or better. Visual acuity improved in 60%, worsened in 6.6% and was unchanged in 33.4% compared with pre-operative levels. Three patients had cystoid macular oedema, 3 ocular hypertension, 2 bullous keratopathy, 1 chronic anterior uveitis and 1 patient developed a retinal detachment. This approach to managing major implant-related complications gives good visual results. There is a significant complication rate but the risk-benefit ratio justifies the use of the technique.

School of Electronics & Communication Engineering

Fulltext

The role of intraocular lens exchange in the management of major implant-related complications

Structure, growth and morphology of various inorganic salts (CaCl2, K2CO3 and CaCO3) was investigated when crystallized in a polyethylene oxide (PEO) matrix. The PEO has profound influence on the crystalline phase and morphology of these salts which crystallize out when added in excess of 2:1 molar ratio. PEO-CaCl2 crystallizes in orthorhombic configuration with a = 8.2 A ̊, b = 13.5 A ̊ and c = 19.26 A ̊, while PEO-K2CO3 has lattice parameters of a = 7.46 A ̊, b = 5.45 A ̊ and c = 7.64 A ̊ with preferential orientation of crystallites. CaCO3 formed "in situ" from these matrices shows a mixed phase of vaterite and monoclinic forms and grows with preferential row nucleation along the polymeric fibres. © 1993.

Polymer-induced crystallization of inorganic salts II. PEO-CaCl2, PEO-K2CO3 and PEO-CaCO3

Crystallization in polyethylene oxide containing high concentrations of Cu(II) chloride has been studied as a function of temperature. As concentrations above 1:4 mole/monomer ratio, highly crystalline acicular morphology is observed which can be attributed to precipitation of the inorganic component. The crystalline structure and morphology of these deposites is strongly influenced by the polymer matrix. The crystallites are seen to grow along the radical direction of the spherulitic domains of the polymer. A new hexagonal type structure with unit cell dimensions of a = 6.52 Å and c = 19 Å is seen to occur for high concentrations of the copper chloride, while an orthorhombic phase is observed at high temperatures. These various findings have been explained on the basis of complex formation at low concentrations with Cu2+ ions being bound within the polymer matrix which acts as the template for subsequent crystallization of the excess salt. © 1992.