Understanding and controlling supramolecular organization and molecular conformation of p-conjugated materials has long been an important challenge relevant to the performance of materials for organic electronics, photonics, etc.  Although it is widely agreed that the bulk organization of conjugated polymers influences device performance, the mechanism of energy transfer in these systems still remains debatable.  Herein, we report the synthesis and properties of the amphiphilic polymer system which was specifically designed to study details of energy transport and its control.  It consists of polythiophene block copolymers attached to a central low-energy gap perylenedicarboximide (PDCI) unit.  The polymer was prepared using PDCI unit as the Ni(II) external initiator of living chain-growth polymerization.  By utilizing an externally initiated Kumada polycondensation, we obtained polymers with well-controlled molecular weight, narrow polydispersity as well as well-defined block copolymers. One of the conjugated blocks was grafted with hydrophilic poly(N-isopropylacrylamide) (PNIPAM) side chains to provide solubility in water and also acting as the temperature-responsive unit.  These polymers showed strong response to external stimuli (such as solvents and temperature) in both solution and solid-state, displaying ratiometric solvatochromic and thermochromic effects in both UV/vis absorption and fluorescent spectra.

Stimuli-responsive amphiphilic polythiophene block copolymers: Solvatochromic and thermochromic effects of conformational reorganization

248th National Meeting (2014)

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