1. Supramolecular extension of pi-conjugation in aniline oligomers. 2. Electroactive vesicle formations in amphiphilic block copolymer and aniline oligomer blends. 3. Collective carboxylic acid doping in aniline oligomers.

摘要

In the first section, extended pi-conjugation of a conjugated aniline oligomer in solution through supramolecular interactions is demonstrated. An unusual red-shifted peak around 990nm was observed in UV-vis in solution when an excess of the acid dopant, dinonylnapthalene sulfonic acid (DNNSA), was introduced. The new red-shifted peak may derive from a self-organizing supramolecular interaction between the oligomer, solvent and the excess of dopant, leading to a lamellar bundle-like supramolecular structure, as indicated by solid state analysis. Conductivity measurements of the prepared thin-films were consistent with the observed trend in solution.; In the second part, electroactive vesicle formation in amphiphilic block copolymer and aniline oligomer blends was investigated. The polystyrene sulfonic acid-b-poly(4-tertbutyl)styrene block copolymer was blended with the aniline trimer to induce microstructure morphologies such as vesicles. The conductivities of the films at different blend compositions were measured. Sufficient conductivities were observed at low loading percentage of the aniline trimer, indicating the formation of bicontinuous network morphology and a possible double percolation mechanism.; In the final part of this dissertation, the doping of aniline oligomers with carboxylic acid derivatives was investigated. Even though carboxylic acids in general are not known to be dopants for inherently conductive materials, effective doping of aniline trimer by a bivalent, 2,6-dicarboxylic acid pyridine, also commonly referred to as dipicolinic acid or (DPA), was observed in solution and confirmed by UV-vis. When benzoic acid which only bears one carboxylic acid group was employed, no doping effect was observed. The acidity of the DPA was much higher than that of benzoic acid at the same concentration. Association of the DPA molecules by intermolecular delocalization of the carboxylic acid group is suggested, which effectively increases the collective acidity of the DPA ensemble.