Materials Poly(3-hexylthiophene) was synthesised according to previous literature. The regioregularity was estimated to be 95 % via H NMR and the number-average molar mass (Mn) and dispersity (Đ), determined via SEC in chlorobenzene at 80 °C, are 58 kg mol -1 and 2.0 respectively. The low and high molar mass hydroxyterminated polydimethylsiloxanes (LPDMS-OH and HPDMS-OH) were purchased from Alfa Aesar and Sigma-Aldrich respectively. Boric acid (B(OH)3) was purchased from Sigma-Aldrich and dried at 120 °C under vacuum before use. All solvents were purchased from Honeywell or Fisher. All chemicals were used as received unless otherwise stated.