*2.1. Materials*

All the chemicals were of Analytical grade. Pyrrole monomer (Fluka Chemie AG, Buchs, Switzerland) was distilled twice before use. Toluene, 2-propanol, benzoyl peroxide (BPO) (≥ 98% Sigma-Aldrich Inc., ST. Louis, MO, USA), N-methyl-2-pyrrolidone (NMP) (RCI Labscan limited Pathumwan, Bangkok, Thailand), dodecylbenzene sulphonic acid (DBSA) and acetone > 98%, Sigma-Aldrich Inc., ST. Louis, MO, USA),were used as received. Double-distilled water was used for solution preparation and for washing glassware.
