In this investigation we report on the synthesis and characterisation of certain polyester elastomers namely as Poly（Sorbitol succinate-co-ethylene glycol succinate） （PSSEG）, Poly（sorbitol succinate-co-butane dio...In this investigation we report on the synthesis and characterisation of certain polyester elastomers namely as Poly（Sorbitol succinate-co-ethylene glycol succinate） （PSSEG）, Poly（sorbitol succinate-co-butane diol succinate） （PSSBD） and Poly（sorbitol succinate-co-hexane diol succinate） （PSSHD） by carrying out catalyst free melt polycondensation.. The synthesised polyesters were characterised by solubility, FT-IR, -H NMR and 13C NMR spectral methods. The thermal properties were analysed by differential scanning calorimetry and thermogravimetric analysis. The mechanical properties evaluated for the polyester films in the tensile mode shows that the polymer has characteristics of elastomers and stiff thermosets. We demonstrate that the chemical structure, physical integrity and mechanical property of synthesized copolyester can be controlled by simply changing the monomers and suit them for the requirements of various biomedical and soft tissue engineering applications.展开更多
The catalytic hydrogenation of nitrobenzene to aniline employing nickel impregnated on rutile,anatase,and high surface area titania supports has been investigated.The nickel is present in elemental state as fcc phase ...The catalytic hydrogenation of nitrobenzene to aniline employing nickel impregnated on rutile,anatase,and high surface area titania supports has been investigated.The nickel is present in elemental state as fcc phase on the catalyst as evidenced by X-ray diffraction results.The Ni crystallite size was found to be greater for Ni/anatase.The temperature-programmed reduction results suggest a greater metal-support interaction for Ni/rutile.The observed order of catalytic activity for the hydrogenation of nitrobenzene is Ni/rutile > Ni/anatase > Ni/TiO2.A conversion of 99% was observed for Ni/rutile at 140 oC and hydrogen pressure of 1.96 MPa.Interestingly,aniline is the only product formed which demonstrates the catalytic hydrogenation of nitrobenzene proceeds with atom economy.Both Ni/rutile and Ni/anatase exhibited a better stability than Ni/TiO2.The hydrogenation proceeds with the preferential adsorption of hydrogen on nickel present in the catalyst surface,possibly assisted by TiOx species.展开更多
A variety of distinctive techniques have been developed to produce graphene sheets and their functionalized subsidiaries or composites. The production of graphene sheets by oxidative exfoliation of graphite can be a s...A variety of distinctive techniques have been developed to produce graphene sheets and their functionalized subsidiaries or composites. The production of graphene sheets by oxidative exfoliation of graphite can be a suitable route for the preparation of high volumes of graphene derivatives. P-substituted graphene material is developed for its application in hydrogen sorption in room temperature. Phosphorous doped graphene material with multi-layers of graphene shows a nearly ~2.2 wt% hydrogen sorption capacity at 298 K and 100 bar. This value is higher than that for reduced graphene oxide (RGO without phosphorous).展开更多
文摘In this investigation we report on the synthesis and characterisation of certain polyester elastomers namely as Poly（Sorbitol succinate-co-ethylene glycol succinate） （PSSEG）, Poly（sorbitol succinate-co-butane diol succinate） （PSSBD） and Poly（sorbitol succinate-co-hexane diol succinate） （PSSHD） by carrying out catalyst free melt polycondensation.. The synthesised polyesters were characterised by solubility, FT-IR, -H NMR and 13C NMR spectral methods. The thermal properties were analysed by differential scanning calorimetry and thermogravimetric analysis. The mechanical properties evaluated for the polyester films in the tensile mode shows that the polymer has characteristics of elastomers and stiff thermosets. We demonstrate that the chemical structure, physical integrity and mechanical property of synthesized copolyester can be controlled by simply changing the monomers and suit them for the requirements of various biomedical and soft tissue engineering applications.
基金supported by Department of Science and Technology,Government of India
文摘The catalytic hydrogenation of nitrobenzene to aniline employing nickel impregnated on rutile,anatase,and high surface area titania supports has been investigated.The nickel is present in elemental state as fcc phase on the catalyst as evidenced by X-ray diffraction results.The Ni crystallite size was found to be greater for Ni/anatase.The temperature-programmed reduction results suggest a greater metal-support interaction for Ni/rutile.The observed order of catalytic activity for the hydrogenation of nitrobenzene is Ni/rutile > Ni/anatase > Ni/TiO2.A conversion of 99% was observed for Ni/rutile at 140 oC and hydrogen pressure of 1.96 MPa.Interestingly,aniline is the only product formed which demonstrates the catalytic hydrogenation of nitrobenzene proceeds with atom economy.Both Ni/rutile and Ni/anatase exhibited a better stability than Ni/TiO2.The hydrogenation proceeds with the preferential adsorption of hydrogen on nickel present in the catalyst surface,possibly assisted by TiOx species.
文摘A variety of distinctive techniques have been developed to produce graphene sheets and their functionalized subsidiaries or composites. The production of graphene sheets by oxidative exfoliation of graphite can be a suitable route for the preparation of high volumes of graphene derivatives. P-substituted graphene material is developed for its application in hydrogen sorption in room temperature. Phosphorous doped graphene material with multi-layers of graphene shows a nearly ~2.2 wt% hydrogen sorption capacity at 298 K and 100 bar. This value is higher than that for reduced graphene oxide (RGO without phosphorous).
