The relative dominance of hydrophobic and electrostatic supramolecular interactions in aqueous solutions of responsive multiblock copolymers was thermoregulated. pH responsive poly(4-vinylpyridine) (P4VP) and thermosensitive random copolymer of N-isopropylacrylamide (NIPAM) and N,N-dimethylacrylamide (DMA), P(NIPAM-co-DMA), were chosen as the two chain sequences alternately arranged in m-P-(NIPAM-co-DMA)-b-P4VP multiblock copolymers. A comparison to the aggregation properties of the multiblock in dilute aqueous solution shows that at 5?C, ionic complexation between protonated P4VP and NDSNa is responsible for the physical gelation, which leads to insolubility of P4VP sequences. Cooling from the gel state at 55?C to 5?C realize sequential gel-sol-gel transition in the reverse order, as compared to that observed in the heating process.
|Pages (from-to)||5184 - 5187|
|Number of pages||4|
|Publication status||Published - 2010|