Hydrophilic-hydrophobic diblock copolymers are self-organized in solution. The self-organized structures showed varied shapes such as spherical, ellipsoids, cylinders, and bilayers, depending on the solution concentration, solvent, and copolymerization ratio of the polymers. In this study, we evaluated the effect of solvent species on the aggregation properties of hydrophilic-hydrophobic p-conjugated diblock copolymers by using DLS and SEM. Hydrophilic-hydrophobic diblock copolymer, S-PDPrB-b-P3HT (SmHTn), containing sulfonic acid functionalized polyphenylene and poly(3-hexylthiophene) blocks, were synthesized via catalyst transfer polycondensation method. The polymerization degrees, m and n, of SmHTn were 15 and 18, which were determined by 1H NMR and GPC measurements. After purified by dialysis for 14 days, S15HT18 was dispersed in water, acetone, methanol, or ethanol to prepare 5×10-2 g L-1 solution. The self-organization properties of S15HT18 in these solutions were evaluated. As a result of DLS measurements at scattering angle of 90°, the particle size of S15HT18were dependent on the solvent species and concentration. The particle size of S15HT18in solution was larger in the order of water, ethanol, methanol, and acetone.Some of these particle solutions showed the scattering angle dependence, suggesting that the particles were not spherical. By freeze-drying the solution, various self-organized particles were obtained. SEM observation showed that the S15HT18aggregates prepared in water, acetone, and methanol were fibrous with various lengths.

Self-organization of hydrophilic-hydrophobic π-conjugated diblock copolymers: Investigation of solvent effect

2019 Fall National Meeting

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