Report on Optical Absorption, Steady-state Emission and Time-resolved Emission Spectroscopy of Carbazole-based Conjugated Polymers

Opto-electronic properties of three new carbazole based co-polymers were investigated. The decay kinetics of triplet emission of the co-polymers was observed. Several findings such as optical band-gap, singlet to singlet transition energies, triplet to singlet transition energies, exchange energies (?EST) have been presented. In comparison to the other material carbazole-oxadiazole based polymer with OMe, P1, H21C10, P2 and H12C10O, P3 exchange energy is below 0.5 eV and triplet energy is significantly higher. The energy gaps between singlet and triplet excited states are 0.44-0.47 eV. From decay kinetics the triplet excited state life-times were found to be several orders of ms at 10-13 K that reduces to less than 3 ms at room temperature.Keywords: Time resolved emission spectroscopy; Carbazole; Conjugated polymers.© 2011 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.doi:10.3329/jsr.v3i1.4666                J. Sci. Res. 3 (1), 13-24 (2011)</jats:p

Ni and Cu oxide supported γ-Al2O3 packed DBD plasma reactor for CO2 activation

The direct activation of undiluted CO2 is carried out in a co-axial dielectric barrier discharge (DBD) reactor. The variation of the electrical discharge parameters and their influence on CO2 decomposition is investigated with the integration of 15 % MO/γ-Al2O3 (M = Ni, Cu) catalyst in the discharge zone. The electrical discharge is found to shift from the filamentary to a combination of surface and micro filamentary discharge on catalyst integration to NTP and also leads to the higher conversion of CO2 than DBD alone. The highest conversion of CO2 (15.7 %) with the energy efficiency of 1.597 mmol/kJ is achieved under CuO/γ-Al2O3 integrated NTP system, whereas the maximum of carbon balance (94.4 %) reaches with 4% CeO2 addition to CuO/Al2O3 catalyst. The oxygen vacancy of the catalyst plays a vital role in improving the performance, especially, the oxygen buffer property of CeO2 facilitates the recombination reaction and contributes to obtaining the highest carbon balance