Freezing as a path to build macroporous structures: Superfast responsive polyacrylamide hydrogels

DINU M. V., OZMEN M. M., DRAGAN E. S., Okay O.

POLYMER, cilt.48, sa.1, ss.195-204, 2007 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 48 Sayı: 1
  • Basım Tarihi: 2007
  • Doi Numarası: 10.1016/j.polymer.2006.11.022
  • Dergi Adı: POLYMER
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.195-204
  • İstanbul Teknik Üniversitesi Adresli: Evet

Özet

Macroporous polyacrylamide (PAAm) hydrogels were prepared from acrylamide monomer and N,N'-methylene(bis)acrylamide (BAAm) crosslinker in frozen aqueous solutions. It was found that the swelling properties and the elastic behavior of the hydrogels drastically change at a get preparation temperature of -6 degrees C. The hydrogels prepared below -6 degrees C exhibit a heterogeneous morphology consisting of pores of sizes 10-70 mu m, while those formed at higher temperatures have a non-porous structure. PAAm networks with largest pores were obtained at -18 degrees C. The pore size of the networks increased while the thickness of the pore walls decreased by decreasing the monomer concentration. The hydrogels formed below -6 degrees C exhibit superfast swelling and deswelling properties as well as reversible swelling-deswelling cycles in water and in acetone, respectively. (c) 2006 Elsevier Ltd. All rights reserved.