Poly(N-isopropylacrylamide-co-N-vinylpyrrolidone) [P(NIPAM-co-NVP)] copolymers with different content of N-vinylpyrrolidone (NVP) were synthesized, and reversible aggregation kinetics of the copolymers in aqueou...Poly(N-isopropylacrylamide-co-N-vinylpyrrolidone) [P(NIPAM-co-NVP)] copolymers with different content of N-vinylpyrrolidone (NVP) were synthesized, and reversible aggregation kinetics of the copolymers in aqueous solutions was investigated with elastic light scattering (ELS) spectra. The results indicated that the apparent activation energy of aggregation process during heating and dissociation process during cooling increased with the NVP content increasing. The phase transition temperature also increased as the content of NVP increased, suggesting that the hydrophilic nature of NVP strongly affected the phase behavior of the copolymer solutions. The higher the content of NVP, the higher the temperature required to break the balance between the hydrophilic and hydrophobie interaction. Besides, during heating and cooling process, the phase transition hysteresis of P(NIPAM-co-NVP) chains decreased when the hydrophilic comonomer increased.展开更多
基金Funded by the National Natural Science Foundation of China(50973129,51273048)the National Natural Science Foundation of Guangdong Province(S2012010009743)
文摘Poly(N-isopropylacrylamide-co-N-vinylpyrrolidone) [P(NIPAM-co-NVP)] copolymers with different content of N-vinylpyrrolidone (NVP) were synthesized, and reversible aggregation kinetics of the copolymers in aqueous solutions was investigated with elastic light scattering (ELS) spectra. The results indicated that the apparent activation energy of aggregation process during heating and dissociation process during cooling increased with the NVP content increasing. The phase transition temperature also increased as the content of NVP increased, suggesting that the hydrophilic nature of NVP strongly affected the phase behavior of the copolymer solutions. The higher the content of NVP, the higher the temperature required to break the balance between the hydrophilic and hydrophobie interaction. Besides, during heating and cooling process, the phase transition hysteresis of P(NIPAM-co-NVP) chains decreased when the hydrophilic comonomer increased.