Controlled grafting of polythiophene and poly(vinylidene fluoride)

Abstract Electroactive polymers (EAPs) have the interesting property of generation and flow of charges and possess exciting tunable optoelectronic properties by incorporating side chains via ‘grafting’ from the backbone chain retaining its properties and importing new properties from the grafted chains. The graft copolymers of EAPs exhibit exciting tunable optoelectronic properties by varying external stimuli like pH, temperature, ions, surfactants, light etc. Grafting of two main electroactive polymers e.g. polythiophene (PT) and poly(vinylidene fluoride) (PVDF) have spurred significant research attention and the controlled grafting has been made using atom transfer radical polymerization (ATRP) technique with suitable catalyst/ligand systems. Few examples of grafting of PT and PVDF by RAFT polymerization are also described. This feature article delineates controlled grafting of different stimuli-responsive polymers on polythiophene and PVDF backbone highlighting their optoelectronic properties, useful for making chemical/biological sensors, logic gates and antifouling/antibacterial membranes. Interactions of the grafted chains with the external physical or chemical stimuli (like pH, temperature, photoirradiation, ions, surfactants, etc.) significantly alter the backbone conformation both in solution and solid state. This leads to changes in conjugation length of the backbone chain, hence tunes the band gap varying the optoelectronic properties useful for fabrication of stimuli dependent sensors and modulation of membrane pore size suitable for antifouling and antibacterial membranes. Graphical Abstract