Conjugated rod-coil block copolymers: Synthesis, morphology, photophysical properties, and stimuli-responsive applications

Conjugated rod-coil block copolymers have been accorded great importance since they provide a powerful route towards supramolecular objects with novel architectures, functions and physical properties. This review summarizes recent progress on the synthesis, morphology, optoelectronic properties and applications of such block copolymers. The combination of the precise condensation and living polymerization through the grafting-from or grafting-onto methodology produce various architectures of conjugated rod-coil block copolymers, including rod-coil, coil-rod-coil, rod-coil-coil, and rod-coil-rod. In the following, the relationships between polymer morphologies and photophysical properties in different phases are reviewed, as classified by solution micelles, thin films or bulk samples, polymer brushes and electrospun nanofibers. The effects of the rod/coil ratio and polymer architecture on the morphology and optoelectronic properties are discussed. The control of nanosize domain and the aligned direction of conjugated rods are the key issues for enhancing the optoelectronic device performance. Moreover, novel multifunctional sensory materials based on combining the tunable photophysical properties of the π-conjugated rod and the stimuli-responsive coil are also highlighted. It is believed that conjugated rod-coil block copolymers could spark the future evolution of nanostructured polymers for multifunctional device applications.