Nano-dimensional self assembly of regioregular poly (3-hexylthiophene) in toluene: Structural, optical, and morphological properties

Abstract

This article presents the optimization and systematic analysis of the growth kinetics of fiber formation of the regio-regular poly (3-hexylthiophene), rr-P3HT. In addition to it a comparative study of as-prepared fiber with fresh, quenched (at -7°C) and commercial rr-P3HT formed in toluene solvent. The rr-P3HT (Mw ≈ 5340; polydispersity ≈ 1.22) is synthesized using a well known Grignard metathesis reaction and characterized by 1HNMR and FTIR techniques. The films obtained by the ageing of rr-P3HT solution for 20 days contain nanostructured fiber with 6-10 nm thickness. However, it acquires a nanostructured globular shape when same concentration of solution is sudden quenched at -7°C. A saturation point for the growth of nano fiber is observed under UV-visible study and it is found that 10 days are sufficient for fiber growth. The concentration dependent free exciton band width of fiber growth is studied by Frank-Condon principle and correlated with AFM morphological studies. © 2014 Wiley Periodicals, Inc.