Polymer Science and Technology Center

Ambernath, India

Polymer Science and Technology Center

Ambernath, India
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Potphode D.D.,Polymer Science and Technology Center | Mishra S.P.,Polymer Science and Technology Center | Sivaraman P.,Polymer Science and Technology Center | Patri M.,Polymer Science and Technology Center
Electrochimica Acta | Year: 2017

Dendritic conducting polymers(CPs) are a novel class of porous pseudocapacitive electrode materials assembled with the combination of highly reversible redox active triphenylamine(TPA) and thiophene, 3-methylthiophene, selenophene and thieno[3,2-b]thiophen moieties. Due to the unique combination of three dimensional conducting network, fast redox reversible reactions, porous morphology, high thermal and electrochemical stability have fetched these pseudocapacitive polymers to exhibit high specific capacitance and emerged as an ideal candidate for energy storage devices. The electrochemical performance of as-prepared polymers showed specific capacitance of 278, 257, 246 and 315 Fg−1 for poly tris[4-(2-thienyl)phenyl]amine (P1), poly tris(4-(3-methylthiophene-2-yl)phenyl)amine (P2), poly tris(4-(selenophen-2-yl)phenyl)amine (P3) and poly tris(4-thieno[3,2-b]thiophen-2-yl) phenyl)amine (P4) respectively with low internal resistance. An insertion of selenophene and thieno(3,2-b)thiophene linkers in TPA block showed enhanced electrochemical performance than the thiophene-TPA pair. Furthermore, asymmetric supercapacitors were assembled with the polymer as cathode and activated carbon as an anode and the detailed electrochemical characterizations has been investigated. This research may shed light on designing new redox active psuedocapacitors and other electrochemical devices. © 2017 Elsevier Ltd


Palai A.K.,Polymer Science and Technology Center | Palai A.K.,Konkuk University | Kumar A.,National Physical Laboratory India | Kumar A.,Konkuk University | And 2 more authors.
Journal of Materials Science | Year: 2014

The synthesis and characterization of a series of polyalkylthiophenes- containing electron-rich thienothiophene (donor heteroaromatic bicycle) and electron-deficient benzothiadiazole (acceptor heteroaromatic bicycle) block have been reported. The polymers are synthesized by Stille cross-coupling reaction and are found to be having high molecular weight with number-average molecular weight in the range of 7.1 × 104-5.7 × 104. The photo-physical, electro-chemical, and electroluminescent (EL) properties of the polymers are investigated in detail. The optical band gap of the polymers is found to be in the range of 1.53-1.54 eV. These new polymers are luminescent in nature and showed red photoluminescence in chloroform solution (722-740 nm) as well as in thin film (781-786 nm). Ionization potential for these polymers is calculated and falling in the range of 5.23-5.33 eV. Polymer light emitting diodes with configuration ITO/PDOT:PSS/polymer/BCP/Alq3/LiF/Al have been fabricated, and a deep red emission is observed. The EL maxima of polymers are found to be in the range of 750-760 nm with threshold voltages around 4.0-5.5 V. The fabricated devices show luminescence around 40 cd/m2 at current density of 100 mA/cm2 with maximum value of 580-810 cd/m2 at 11 V. Graphical abstract: [Figure not available: see fulltext.] © 2013 Springer Science+Business Media New York.


Kolli B.,Polymer Science and Technology Center | Mishra S.P.,Polymer Science and Technology Center | Palai A.K.,Polymer Science and Technology Center | Kanai T.,Polymer Science and Technology Center | And 5 more authors.
Journal of Polymer Science, Part A: Polymer Chemistry | Year: 2013

A series of dicyanomethylene-substituted polymers having Y-type molecular architecture were synthesized by Knoevenagel condensation reaction. The polymers were found to be soluble in organic solvents like tetrahydrofuran and chloroform. From gel permeation chromatography, the molecular weights of the polymers were found to be in the range of 15,300-33,800 g/mol. Thermal analysis showed that the polymers were stable up to 350 °C with glass transition temperature (Tg) in the range of 129-212 °C. These polymers were found to form good optical quality films. The order parameter was calculated to be in the range of 0.01-0.48. Atomic force microscopy indicated prominent morphology changes due to alignment of dipoles after poling. By using Nd:YAG laser of 1064 nm, angular dependence and temperature dependence of second-harmonic generation intensity were investigated. The geometry optimization, shape of polymers, and restricted torsion angle between acceptor and donor substituents (push-pull system) were calculated. © 2012 Wiley Periodicals, Inc.


Kolli B.,Polymer Science and Technology Center | Mishra S.P.,Polymer Science and Technology Center | Joshi M.P.,Raja Ramanna Center for Advanced Technology | Raj Mohan S.,Raja Ramanna Center for Advanced Technology | And 2 more authors.
Journal of Polymer Science, Part A: Polymer Chemistry | Year: 2012

Four linear polymers containing pendant azo moiety were synthesized through click chemistry for second-order nonlinear optical study. The polymers were found soluble in most of the polar organic solvents such as tetrahydrofuran (THF), chloroform, and dimethyl formamide (DMF). The polymers showed thermal stability up to 300 °C and glass transition temperatures (T g) in the range of 120-140 °C. The molecular weights (M w) of these polymers (measured by gel permeation chromatography) were in the range 37,900-55,000 g/mol. The polymers were found to form optically transparent films by solution casting from THF solution. Order parameters were calculated from UV-vis absorption spectra. The morphology changes in the films after poling were characterized by atomic force microscopy. The angular dependence, temperature dependence, and time dependence of second harmonic generation (SHG) intensity were obtained by using 1064 nm Nd:YAG laser. The SHG intensity remained unchanged up to 95 °C. At room temperature, it remained stable up to 8 days after initial drop of about 14%. © 2012 Wiley Periodicals, Inc.


Samui A.B.,Indian Defence Institute of Advanced Technology | Pandey S.,Polymer Science and Technology Center | Mishra S.P.,Polymer Science and Technology Center
RSC Advances | Year: 2015

Liquid crystalline siloxane azo polymers were synthesized through hydrosilylation reaction between diallyl azo monomer and siloxane dihydride. The molecular weights of the polymers ranged from 3000-4000 g mol-1. The polymers were found to be soluble in chloroform, THF, DMF, DMSO, and DCM respectively. The photoresponsive behavior was studied during exposure of the polymers to UV radiation. The trans-cis photoisomerisation rate constants were also determined. The thermotropic behavior of the polymers was studied by using polarizing optical microscopy (POM) and differential scanning calorimetry (DSC). The polymers exhibited liquid crystalline texture of nematic droplets in POM images existing at room temperature and extending over broad temperature range up to 155 °C. The DSC thermogram also supported the characteristic liquid crystalline transitions. © The Royal Society of Chemistry 2015.


Potphode D.D.,Polymer Science and Technology Center | Sivaraman P.,Polymer Science and Technology Center | Mishra S.P.,Polymer Science and Technology Center | Patri M.,Polymer Science and Technology Center
Electrochimica Acta | Year: 2015

In the present study, polyaniline (PANI)/partially exfoliated multi-walled carbon nanotubes (Px-MWCNT) nanocomposites were investigated for supercapacitor application. Nanocomposites with varying weight/weight ratio of PANI and Px-MWCNT were prepared by in-situ polymerization of aniline over Px-MWCNT. Transmission and scanning electron microscopic analysis showed that the MWCNT was partial unzipped along the length of tubes. The morphology of PANI/Px-MWCNT nanocomposites exhibited wrapping of PANI over Px-MWCNT. Symmetric supercapacitors containing PANI/Px-MWCNT nanocomposites as the electrode material were fabricated. The electrochemical characterization of the nanocomposites was carried by two electrode method (unit cell configuration). Cyclic voltammetric analysis showed a synergistic increase in specific capacitance of the nanocomposites. Charge-discharge cycle study indicated that nanocomposites have greater charge-discharge rate capability than pure PANI. The observed result is attributed to the shorter diffusion length of ions in the nanocomposites as compared to that of pure PANI. The electrochemical impedance spectra of supercapacitors were resolved into real and losscapacitances. The loss capacitance indicated that the time constant of the nanocomposites decreases with increase in the Px-MWCNT content. The supercapacitors showed enhanced stability during continuous charge-discharge cycling as the PX-MWCNT content in the nanocomposites increased. PANI-50 and PANI-25 nanocomposites based supercapacitors exhibited 91% and 93% capacitive retention after 2000 charge-discharge cycle while pure PANI showed only 67% capacitance retention for the same number of cycles. © 2015 Published by Elsevier Ltd.


Jagtap S.B.,Polymer Science and Technology Center | Rao V.S.,Polymer Science and Technology Center | Barman S.,Polymer Science and Technology Center | Ratna D.,Polymer Science and Technology Center
Polymer (United Kingdom) | Year: 2015

The pristine clay (Cloisite Na+) is modified with a half neutralized salt of three polyetheramines having different molecular weight of polyether chain. The clay is dispersed into a rubbery epoxy network. The half neutralized salt of a polyetheramine is selected in such way that it consists of a free -NH2 group which can react with the epoxy resin within the clay gallery. The intragallery reaction rate is manipulated by changing the molecular weight of polyether chain of the half neutralized salt of polyetheramine. Curing behaviors of the epoxy/clay nanocomposites were studied by using a temperature modulated differential scanning colorimetry (MDSC) under a non-isothermal condition. The intragallery reaction rate plays an important role in deciding the morphology and thermomechanical properties of the epoxy nanocomposites. A quantitative measurement of constrained region (macromolecular chains immobilized by the clay platelets) was also carried out for the epoxy nanocomposites. © 2015 Elsevier Ltd. All rights reserved.


Pandey S.,Polymer Science and Technology Center | Mishra S.P.,Polymer Science and Technology Center | Kolli B.,Polymer Science and Technology Center | Kanai T.,Polymer Science and Technology Center | Samui A.B.,Polymer Science and Technology Center
Journal of Polymer Science, Part A: Polymer Chemistry | Year: 2012

Three new types of hyperbranched photoactive liquid crystalline siloxane polymers containing azo moieties were synthesized using click chemistry methodology. The polymers were soluble in most of the polar solvents like chloroform, tetrahydrofuran, dimethylformamide, dimethyl sulphoxide and dichloromethane. The molecular weights of the polymers were in the range of 9000-12,000 g mol -1. The trans-cis photoisomerization of the polymer were studied both under UV radiation and dark. The isomerization rate constants were found to be in the range of 0.7-1.4 × 10 -2 sec -1 and 7.0 × -2.5 × 10 -5 sec -1. The thermotropic behavior of the polymers was studied by using polarizing optical microscopy and differential scanning calorimetry, respectively. The polymers P1 and P2 showed liquid crystalline texture characteristic of nematic phase. © 2012 Wiley Periodicals, Inc.


Ghorpade T.K.,Polymer Science and Technology Center | Patri M.,Polymer Science and Technology Center | Mishra S.P.,Polymer Science and Technology Center
Sensors and Actuators, B: Chemical | Year: 2016

Four novel deeply coloured and highly fluorescent anion sensors have been developed by coupling calix[4]pyrrole with two different diketopyrrolopyrroles. The sensors showed both colorimetric and fluorometric sensitization by selective anions. Complexation properties of the receptors with anions like halides, acetate, phosphate, sulphate, hydrogen sulphate, perchlorate and cyanide were investigated by UV-vis spectroscopy and fluorescence spectroscopy. Sharp visual colour changes as well as complete fluorescence quenching was observed in the presence of selective anions like fluoride, acetate, phosphate and cyanide. Visual detection of sensing properties was achievable up to anion concentration of 1.15 ppm for detection in visible light and 0.025 ppm under UV light. One of the sensor, namely S1, showed a dramatic colour change in the presence of CN- ion. Furthermore, a cheap and highly efficient procedure for bulk scale synthesis of monoiodo-octamethylcalix[4]pyrrole, which is one of the main building blocks for the design of calix[4]pyrrole based sensors has been developed. © 2015 Elsevier B.V. All rights reserved.


Jagtap S.B.,Polymer Science and Technology Center | Kushwaha R.K.,Polymer Science and Technology Center | Ratna D.,Polymer Science and Technology Center
RSC Advances | Year: 2015

Nanocomposites of poly (ethylene oxide) (PEO) and graphene were made in aqueous solution using an organic salt containing a carboxylate ion and a carboxylic acid group. The cation corresponding to the carboxylate ion interacts with the π electron clouds of graphene through cation-π interaction and promotes the exfoliation of graphene sheets. The carboxylic acid group of the modifier forms H-bonds with the PEO and thereby improves interfacial adhesion. The effect of the number of carbon atoms present in the modifier on its dispersing ability was investigated. It was observed that there exists an optimum number of carbon atoms present in the modifier with respect to the level of dispersion of graphene in the related nanocomposites as examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The mechanical properties of the nanocomposites having various concentrations of graphene were evaluated and compared with the theoretical values using the Halpin-Tsai model. The crystallization behavior of the PEO upon incorporation of modified graphene was studied by temperature modulated differential scanning colorimetry (MDSC) and discussed as well. The dispersion process used here is green as it does not require any toxic solvent or hazardous material for modification of graphene. This journal is © The Royal Society of Chemistry 2015.

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