Development of Functional Temperature-Responsive Poly(styrene-co-N-isopropy-lacrylamide) Latex for Enzyme Immobilization

陳志平(Jyh-Ping Chen) ； 蘇大榮(Da-Rong Su)

《Journal of the Chinese Institute of Chemical Engineers》 32卷3期 (2001/05) Pp. 241-251

https://doi.org/10.6967/JCICE.200105.0241

並列摘要

Latex particles composed of styrene, N –isopropylacrylamide (NIPAAm), and MAA or GMA were synthesized by emulsifier-free emulsion polymerization. These sub-micron core-shell type non-porous lattices are temperature-responsive due to the presence of temperaturesensitive monomer (NIPAAm), and shows reversible flocculation/dispersion properties in response to change in temperature and/or salinity. The comonomer MAA or GMA could provide functional groups for immobilization of enzyme through covalent bindings. Immobilized a-chymotrypsin could be reused for 10 times after thermal flocculation and sedimentation of the enzyme-containing lattices in 1 M saline at 30°C , followed by re-dispersion in cold buffer. The optimum conditions for enzyme immobilization were studied and discussed, including polymer compositions, concentration of activation reagent, immobilization pH, and enzyme loading. Immobilized enzyme showed enhanced thermal stability compared with free enzyme. The specific activity of enzyme after immobilization is close to that of the free enzyme for GMA-containing latex, and around 40% of the free enzyme for MAA-containing latex, even for macromolecular substrates such as casein.

並列關鍵字

Latex ； Temperature -Responsive ； N-isopropylacrylamide ； Thermo-flocculation