聚(N-异丙基丙烯酰胺)的体积相转变及在分离领域中的应用研究

DEVELOPMENT OF POLY(N-ISOPROPYLACRYLAMIDE) IN SEPARATION SYSTEMS

介绍了温敏型高分子聚 (N-异丙基丙烯酰胺 )的体积相转变行为 ,影响体积相转变的因素 。

Theoretical models derived to explain the origins of the LCST of poly(N isopropylacrylamide) (PNIPAAM) hydrogels were discussed, both hydrogen bonding and hydrophobic effect were considered to contribute to the driving force for the transition. The discontinuous volume phase transitions of PNIPAAM and its copolymer gels stimulated by temperature, solvent composition, pH, ionic composition, photo and electric field were described. Application of PNIPAAM gels in separation was based on the swelling shrinking behavior of gels and size exclusion by the gel network, for solvent extraction or solute separation. Temperature sensitive membranes were also prepared by graft PNIPAAM onto porous membranes, the grafted chains acted as a thermosensitive valve to regulate the membrane pore size. The reversible changes of the grafted chains, namely hydrophobicity or hydrophilicity, can be utilized for adsorptive or desorptive separation. 34 references refered.