3.3.3. Other effects
The self-assembly thin film morphology of rod–coil block copolymers can also be controlled by several effects, such as solvent, solution concentration, and substrate. For example, thin films of the oligofluorene–HEMA block copolymers formed either islands, a string-like morphology, or honeycomb-like structures by increasing the selective solvent concentration [72]. McCullough and coworkers synthesized a head-to-tail-coupled P3HT-b-PS and the strong tendency of regioregular P3HT to self-assemble into stacked aggregates resulted in the formation of highly conducting nanowires ( Fig. 28) [47]. They also incorporated the PAA as the coil block to synthesize the amphiphilic nature of P3HT-b-PAA, which yielded solvatochromic behavior in several solvents of varying polarity [49]. UV–vis absorption spectra revealed the presence of a vibronic structure in most polar solvents, pointing to the long range ordering of P3HT based the self-assembly characteristic. Hillmyer and coworkers reported another regioregular P3HT-b-PLA copolymers and formed a nanopitted film upon chemical etching of the PLA block [54].