The Experts below are selected from a list of 5133 Experts worldwide ranked by ideXlab platform
Amish G. Joshi - One of the best experts on this subject based on the ideXlab platform.
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Highly conductive poly(3,4-ethylenedioxypyrrole) and poly(3,4-ethylenedioxythiophene) enwrapped Sb2S3 nanorods for flexible supercapacitors
Physical chemistry chemical physics : PCCP, 2014Co-Authors: B. Narsimha Reddy, Melepurath Deepa, Amish G. JoshiAbstract:Composites of poly(3,4-ethylenedioxypyrrole) or PEDOP and poly(3,4-ethylenedioxythiophene) or PEDOT enwrapped Sb2S3 nanorods have been synthesized for the first time for use as supercapacitor electrodes. Hydrothermally synthesized Sb2S3 nanorods, several microns in length and 50−150 nm wide, offer high surface area and serve as a scaffold for coating conducting polymers, and are a viable alternative to carbon nanostructures. Fibrillar morphologies are achieved for the PEDOP–Sb2S3 and PEDOT–Sb2S3 films in contrast to the regular granular topologies attained for the neat polymers. The remarkably high nanoscale (∼5 S cm−1) conductivity of the Sb2S3 nanorods enables facile electron transport in the composites. We constructed asymmetric supercapacitors using the neat polymer or composite and graphite as electrodes. High specific capacitances of 1008 F g−1 and 830 F g−1 (at 1 A g−1), enhanced power densities (504 and 415 W kg−1) and excellent cycling stability (88 and 85% capacitance retention at the end of 1000 cycles) are delivered by the PEDOP–Sb2S3 and PEDOT–Sb2S3 cells relative to the neat polymer cells. A demonstration of a light emitting diode illumination using a light-weight, flexible, supercapacitor fabricated with PEDOP–Sb2S3 and carbon-fiber cloth shows the applicability of Sb2S3 enwrapped conducting polymers as sustainable electrodes for ultra-thin supercapacitors.
Suresh Chand - One of the best experts on this subject based on the ideXlab platform.
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Poly(3,4-ethylenedioxyselenophene) and its derivatives: novel organic electronic materials.
Accounts of chemical research, 2014Co-Authors: Asit Patra, Michael Bendikov, Suresh ChandAbstract:Since the discovery of high conductivity in iodine-doped polyacetylene, many interesting conducting polymers have been developed. Of these, polythiophenes have been most studied as electronic materials, with poly(3,4-ethylenedioxythiophene) (PEDOT) and the water-soluble PEDOT-PSS being the most successful commercially used conducting polymers. The polyselenophene family together with poly(3,4-ethylenedioxyselenophene) (PEDOS) and its derivatives have been shown to have slightly different properties compared to these of polythiophene and PEDOT because of their different electron donating characters, aromaticities (selenophene vs thiophene), oxidation potentials, electronegativities, and polarizabilities (Se vs S). As a result, the polyselenophenes, especially PEDOS and its derivatives, show a lower band gap and higher-lying highest occupied molecular orbital (HOMO) levels compared with those of thiophene and the PEDOT family. In an organic materials context, the PEDOS family offers some advantages over PEDOT derivatives. This Account draws on computational studies, synthetic methods, electrochemical polymerizations, chemical polymerizations, and the materials properties of PEDOS and its derivatives to demonstrate the importance of these novel materials, which lie at the frontier of conducting polymer research. In particular, we show that (i) PEDOS derivatives have a lower band gap (about 0.2 eV) than the corresponding PEDOT derivatives. Consequently, PEDOS derivatives can absorb the solar spectrum more efficiently compared to PEDOT derivatives and the properties of optoelectronic devices based on neutral and doped PEDOS should be somewhat different from these of PEDOT. (ii) EDOS derivatives have a greater tendency to undergo electrochemical polymerization compared to EDOT derivatives and offer stable and smooth polymer films. (iii) The PEDOS backbone is more rigid than the PEDOT backbone. (iv) PEDOS derivatives are excellent electrochromic materials with high transparency, and have higher contrast ratio and coloration efficiency. (v) The PEDOS/C electrode offers better control over the formation and size of nanoparticles through Se···Pt interactions compared with the PEDOT/C electrode. In addition to this, we summarize the synthesis, electrochemical polymerization, materials properties, and computational studies of fused polyselenophene analogues, namely, poly(cyclopenta[c]selenophene), and a series of low band gap thieno- or selenolo-fused polyselenophenes and selenolo-fused polythiophene. Additionally, we discuss oxidative and solid state polymerization to obtain conducting PEDOS, and its derivatives, and made throughout comparison with S-analogue where applicable. We found that EDOS-based derivatives have a greater tendency toward solid state polymerization and working at a temperature about 20 °C lower than that required for EDOT-based compounds. Our results demonstrate the utility of EDOS unit for generating promising materials PEDOS and its derivatives for electronic devices. Consequently, EDOS structure is the basis for many functionalized polymers and copolymers with tunable optoelectronic and redox properties. These interesting properties, which include high conductivity, lower band gap, rigidity, multicolor electrochromism, and rapid redox switching, allow them to be used in a variety of electronic applications.
B. Narsimha Reddy - One of the best experts on this subject based on the ideXlab platform.
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Highly conductive poly(3,4-ethylenedioxypyrrole) and poly(3,4-ethylenedioxythiophene) enwrapped Sb2S3 nanorods for flexible supercapacitors
Physical chemistry chemical physics : PCCP, 2014Co-Authors: B. Narsimha Reddy, Melepurath Deepa, Amish G. JoshiAbstract:Composites of poly(3,4-ethylenedioxypyrrole) or PEDOP and poly(3,4-ethylenedioxythiophene) or PEDOT enwrapped Sb2S3 nanorods have been synthesized for the first time for use as supercapacitor electrodes. Hydrothermally synthesized Sb2S3 nanorods, several microns in length and 50−150 nm wide, offer high surface area and serve as a scaffold for coating conducting polymers, and are a viable alternative to carbon nanostructures. Fibrillar morphologies are achieved for the PEDOP–Sb2S3 and PEDOT–Sb2S3 films in contrast to the regular granular topologies attained for the neat polymers. The remarkably high nanoscale (∼5 S cm−1) conductivity of the Sb2S3 nanorods enables facile electron transport in the composites. We constructed asymmetric supercapacitors using the neat polymer or composite and graphite as electrodes. High specific capacitances of 1008 F g−1 and 830 F g−1 (at 1 A g−1), enhanced power densities (504 and 415 W kg−1) and excellent cycling stability (88 and 85% capacitance retention at the end of 1000 cycles) are delivered by the PEDOP–Sb2S3 and PEDOT–Sb2S3 cells relative to the neat polymer cells. A demonstration of a light emitting diode illumination using a light-weight, flexible, supercapacitor fabricated with PEDOP–Sb2S3 and carbon-fiber cloth shows the applicability of Sb2S3 enwrapped conducting polymers as sustainable electrodes for ultra-thin supercapacitors.
Wen-chang Chen - One of the best experts on this subject based on the ideXlab platform.
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Synthesis and Properties of New Small Band Gap Conjugated Polymers: Methine Bridged Poly(3,4-ethylenedioxypyrrole)
Polymer Journal, 2009Co-Authors: Jung-hsun Tsai, Wei-ren Tu, Wen-chung Wu, Wen-chang ChenAbstract:Synthesis and electronic properties of new small band gap conjugated polymers, methine-bridged poly(3,4-ethylenedioxy-pyrrole) ( PEDOP ) are reported. Density functional theory (B3LYP with 6-31G basis) are used to obtain the optimized ground-state geometries and electronic structures of PEDOP and poly[(3,4-ethylenedioxypyrrole-2,5-diyl) methine] ( PEDOP-M ). Theoretical bond length alternation of PEDOP is reduced by incorporating the methine bridge and leads to the band gap reduction from 2.44 to 0.68 eV. The small band gap characteristic of PEDOP-M is further verified by preparing two conjugated polymers, poly[(2,5-n-benzyl-3,4-ethylenedioxypyrrolediyl)-benzylidene-(2,5-n-benzyl-3,4-ethylenedioxypyr-role-quinodimethanediyl)] ( PbEDOP-b ) and poly[(2,5-n-benzyl-3,4-ethylenedioxypyrrolediyl)-(p-nitrobenzylidene)-(2,5-n-benzyl-3,4-ethylenedioxypyrrole-quinodimethanediyl)] ( PbEDOP-nb ). The optical band gap of PbEDOP-b and PbEDOP-nb are 1.77 and 1.45 eV, respectively, while the electrochemical band gap of the former is 1.59 eV. Although the bulky side groups of these two polymers result in a larger band gap than that of PEDOT-M , it indicates the small band gaps of such polymers. The nitrobenzene group could extend the π-conjugation and lead to the smaller band gap of PbEDOP-nb than that of PbEDOP-b . The present study suggests that methine-bridged poly(3,4-ethylenedioxypyrrole) is a class of small band gap polymers.
Asit Patra - One of the best experts on this subject based on the ideXlab platform.
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Poly(3,4-ethylenedioxyselenophene) and its derivatives: novel organic electronic materials.
Accounts of chemical research, 2014Co-Authors: Asit Patra, Michael Bendikov, Suresh ChandAbstract:Since the discovery of high conductivity in iodine-doped polyacetylene, many interesting conducting polymers have been developed. Of these, polythiophenes have been most studied as electronic materials, with poly(3,4-ethylenedioxythiophene) (PEDOT) and the water-soluble PEDOT-PSS being the most successful commercially used conducting polymers. The polyselenophene family together with poly(3,4-ethylenedioxyselenophene) (PEDOS) and its derivatives have been shown to have slightly different properties compared to these of polythiophene and PEDOT because of their different electron donating characters, aromaticities (selenophene vs thiophene), oxidation potentials, electronegativities, and polarizabilities (Se vs S). As a result, the polyselenophenes, especially PEDOS and its derivatives, show a lower band gap and higher-lying highest occupied molecular orbital (HOMO) levels compared with those of thiophene and the PEDOT family. In an organic materials context, the PEDOS family offers some advantages over PEDOT derivatives. This Account draws on computational studies, synthetic methods, electrochemical polymerizations, chemical polymerizations, and the materials properties of PEDOS and its derivatives to demonstrate the importance of these novel materials, which lie at the frontier of conducting polymer research. In particular, we show that (i) PEDOS derivatives have a lower band gap (about 0.2 eV) than the corresponding PEDOT derivatives. Consequently, PEDOS derivatives can absorb the solar spectrum more efficiently compared to PEDOT derivatives and the properties of optoelectronic devices based on neutral and doped PEDOS should be somewhat different from these of PEDOT. (ii) EDOS derivatives have a greater tendency to undergo electrochemical polymerization compared to EDOT derivatives and offer stable and smooth polymer films. (iii) The PEDOS backbone is more rigid than the PEDOT backbone. (iv) PEDOS derivatives are excellent electrochromic materials with high transparency, and have higher contrast ratio and coloration efficiency. (v) The PEDOS/C electrode offers better control over the formation and size of nanoparticles through Se···Pt interactions compared with the PEDOT/C electrode. In addition to this, we summarize the synthesis, electrochemical polymerization, materials properties, and computational studies of fused polyselenophene analogues, namely, poly(cyclopenta[c]selenophene), and a series of low band gap thieno- or selenolo-fused polyselenophenes and selenolo-fused polythiophene. Additionally, we discuss oxidative and solid state polymerization to obtain conducting PEDOS, and its derivatives, and made throughout comparison with S-analogue where applicable. We found that EDOS-based derivatives have a greater tendency toward solid state polymerization and working at a temperature about 20 °C lower than that required for EDOT-based compounds. Our results demonstrate the utility of EDOS unit for generating promising materials PEDOS and its derivatives for electronic devices. Consequently, EDOS structure is the basis for many functionalized polymers and copolymers with tunable optoelectronic and redox properties. These interesting properties, which include high conductivity, lower band gap, rigidity, multicolor electrochromism, and rapid redox switching, allow them to be used in a variety of electronic applications.
