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The sol‐gel approach towards thermo‐responsive poly(N‐isopropyl acrylamide) hydrogels with improved mechanical properties
Author(s) -
Loos Wouter,
Du Prez Filip
Publication year - 2004
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.200450654
Subject(s) - self healing hydrogels , materials science , chemical engineering , acrylamide , polymer , sol gel , polymer chemistry , aqueous solution , composite material , nanotechnology , chemistry , copolymer , organic chemistry , engineering
A new type of thermo‐responsive hydrogels based on the polymer poly(N‐isopropyl acrylamide) (PNIPAA) has been synthesized with the sol‐gel technology. For the preparation of this type of nano‐structured hydrogels, the inorganic silica phase was synthesized by the sol‐gel process in the presence of an aqueous solution of high molecular weight PNIPAA. This combination of the organic and inorganic phases forms hybrid hydrogels with a semi‐IPN morphology. The unique structure of these hydrogels improves the mechanical stability to a great extent as compared to conventional PNIPAA‐hydrogels. This was shown by stress‐strain experiments and the capability to absorb and desorb large amounts of water. The silica only slightly influences the transition temperature of the hydrogels but allows us to vary the thermo‐responsive properties of the materials to a great extent.