Effect of freeze-drying and rehydrating treatment on the thermoresponsive characteristics of poly(N-isopropyl-acrylamide) microspheres
Investigations on the effect of freeze-drying and rehydrating treatment on equilibrium volume changes and on the thermo-response rate of poly(N-isopropylacrylamide) (PNIPAM) microspheres were carried out. The experimental results showed that freeze-drying and rehydrating treatment had nearly no effecton the low critical solution temperature and equilibrium volume changes of PNIPAM microspheres. Furthermore, when the PNIPAM microspheres was treated by frozen in only liquid nitrogen as rapid cooling,the response rate of PNIPAM microspheres to environmental temperature change was nearly not affected by the treatment either, which was surprisingly different from the macroscopic hydrogel. The dimension effectwas responsible for this phenomenon. Micron-sized PNIPAM microsphere itself has a much quicker responserate compared with the bulky hydrogel owing to that the characteristic time of gel deswelling is proportional to the square of a linear dimension of the hydrogel.
Thermo-sensitive microspheres SPG membrane emulsification Colloidal drug carriers Thermo-response rate Freeze-drying
CHENG Chang-Jing CHU Liang-Yin ZHANG Jie WANG Hai-Dong WEI Gang XIE Rui
School of Chemical Engineering, Sichuan University, Chengdu, Sichuan 610065, China Institute for Nanobiomedical Technology and Membrane Biology, State Key Laboratory of Biotherapy, Si
国际会议
第四届中日化工学术研讨会(The 4th Joint China/Japan Chemical Engineering Symposium)(CJCES)
成都
英文
2007-12-19（万方平台首次上网日期，不代表论文的发表时间）