Aromatic azo-polyamide electrolyte with liquid crystal structure and photoelectrical properties

A dissoluble aromatic azo-polyamide electrolyte containing azobenzene derivatives in the main-chain is successfully prepared by ionizing amide nitrogens of poly(p-phenylene, 4,4′-azobenzene phthalamide) (Azo-PA) with the sodium methyl sulfinyl carbanion. The conductometric titration measurement shows that 95–98 mol.% of amide nitrogens were converted into anions. Orthogonal polarizing optical microscope images and UV–vis spectra reveal that this Azo-PA anion solution has formed a kind of lytropic liquid crystal structure in anhydrous dimethyl sulfoxide (DMSO) and represents great photoresponsive properties. The Azo-PA formed typical spherocrystal structure after precipitating from the solution when came across water. The photoelectrical properties are investigated by a precise digital conductance instrument and a ZF-7A UV-light examining lamp which can produce 365 nm UV-light. The results indicate that the conductivity value increases by a factor of 0.300–0.320 ms/cm upon UV irradiation and comes back to the initial value under visible light.