Thermo-Responsive Hydrogels with Nanodomains: Rapid Shrinking of a Nanogel-Crosslinking Hydrogel of Poly(N-isopropyl acrylamide)

✍ Scribed by Nobuyuki Morimoto; Takafumi Ohki; Kimio Kurita; Kazunari Akiyoshi

• Publisher: John Wiley and Sons
• Year: 2008
• Tongue: English
• Weight: 238 KB
• Volume: 29
• Category: Article
• ISSN: 1022-1336
• DOI: 10.1002/marc.200700864

✦ Synopsis

Abstract

Rapidly shrinking poly(N‐isopropyl acrylamide) (PNIPAM) hydrogels are prepared by crosslinking with self‐assembled nanogels that consist of cholesteryl‐ and methacryloyl‐substituted pullulan (CHPMA). The CHPMA nanogel (R~h~ = 26.4 nm) was used as a crosslinker for a hydrophilic nanodomain. Transmission electron microscopy images of the nanogel‐crosslinked PNIPAM hydrogel reveal a well‐defined nanoporous structure. The nanogel‐crosslinked PNIPAM hydrogel shows rapid shrinking based on its structure. The shrinking half‐time was ≈2 min, which is about 3 400 times faster than that of a PNIPAM hydrogel crosslinked by methylene(bisacrylamide).

magnified image