As discussed above, the morphology and photophysical properties of conjugated rod–coil block copolymers can be efficiently tuned through the chemical structure of the copolymers, solvent polarity, pH, temperature, etc. Correspondingly, stimuli-responsive polymers are defined as polymers that undergo relatively large and abrupt, physical (such as temperature, solvents, and light) or chemical changes (such as reactants, pH, ions in solution, and chemical recognition) in response to small external changes in the environmental conditions