Fast responsive poly(N, N-diethylacrylamide) hydrogels with interconnected microspheres and bi-continuous structures

Ryoichi Kishi, Aritoshi Matsuda, Toshiaki Miura, Kazunari Matsumura, Kokoro Iio

Research output: Contribution to journalArticle

6 Citations (Scopus)


We prepared thermo-responsive polymer hydrogels by γ0-ray irradiation of aqueous solutions of N, N-diethylacrylamide at different temperatures below and above its lower critical solution temperature (LCST). Poly(N, N-diethylacrylamide) gel had a transparent and homogeneous structure when the radiation-induced polymerization and crosslinking were carried out below the LCST (25 °C) of the polymer. On the other hand, cloudy and heterogeneous gels were formed at temperatures above the LCST of the polymer (>35 °C). From environmental scanning electron microscopy observations, the gels prepared at 35 and 40 °C were seen to show sponge-like bi-continuous porous structures, while those prepared at 50 °C showed a porous structure consisting of interconnected microspheres. For temperature changes between 10 and 40 °C, gels with porous structures showed rapid volume transitions on a time scale of about a minute, not only for shrinking but also for swelling processes, which is in remarkable contrast to the porous poly(N-isopropylacrylamide) hydrogels.

Original languageEnglish
Pages (from-to)505-512
Number of pages8
JournalColloid and Polymer Science
Issue number5
Publication statusPublished - 2009 Jan 28



  • Bi-continuous structure
  • Gel
  • Microsphere
  • Poly(N, N-diethylacrylamide)
  • Volume transition

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Polymers and Plastics
  • Colloid and Surface Chemistry
  • Materials Chemistry

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