Synthesis and characterisation of π-conjugated polymer/silica hybrids containing regioregular ionic polythiophenes

Abstract

Highly regioregular poly{3-[n-(1-methylimidazolium-3-yl)alkyl]thiophene-2,5-diyl bromide} (n = 4, 6, 8) (10–12) has been prepared by reaction of poly[3-(n-bromoalkyl)thiophene-2,5-diyl] (n = 4, 6, 8) (7–9) with 1-methylimidazole. Acid-catalyzed hydrolysis and polycondensation of tetraethoxysilane (TEOS) were carried out in the presence of these polymers. The strong ionic interactions between the imidazolium moieties of the polythiophene and the charged silanol groups enabled the homogeneous dispersion of the polythiophene within silica. The resulting composite materials were characterised by SEM, TEM and tapping mode atomic force microscopy (TM-AFM). The optical and thermal properties were investigated by UV and TGA measurements.