Synthesis of water-free PEDOT with polyvinylpyrrolidone stabilizer in organic dispersant system

Abstract

Abstract Poly (3, 4-ethylenedioxythiophene): tosylate (PEDOT: Tos) is synthesized by chemical oxidative polymerization with polyvinylpyrrolidone (PVP) as stabilizer in organic solvent. The effects of different molecular weight and additive amount of PVP stabilizer, various volume ratios of propylene carbonate (PC) to ethanol in organic system, different oxidative agents and various polymerization temperature/time on as-prepared PEDOT dispersion are taken into consideration and investigated systematically. Fourier transform infrared spectroscopy (FT-IR), film-forming property and electrical conductivity are studied and compared among different reaction conditions. The optimal polymerization scenario is to prepare PEDOT particles with 2 wt.% PVP (M.w. = 58,000) stabilizer and Fe2(SO4)3 oxidant at 80 °C for 24 h in organic system of PC and ethanol (volume ratio = 1: 3). Optimal PEDOT with PVP possesses more homogeneous particle size, better particle-particle connectivity in film and higher electrical conductivity (1.67*10−2 s cm−1) than that of PEDOT without PVP (5.2*10−4 s cm−1) and commercial organic PEDOT (4.7*10−4 s cm−1). The morphology and elemental composition of PEDOT particles with PVP are also investigated and compared with that of commercial organic PEDOT and aqueous PEDOT/PSS dispersion.