Swelling of acrylamide gels made at various onset temperatures: an optical transmission study


Pekcan O., Kara S.

POLYMER INTERNATIONAL, vol.52, no.5, pp.676-684, 2003 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 52 Issue: 5
  • Publication Date: 2003
  • Doi Number: 10.1002/pi.982
  • Title of Journal : POLYMER INTERNATIONAL
  • Page Numbers: pp.676-684

Abstract

Optical transmission experiments were performed using a UV-visible spectrometer during the swelling of polyacrylamide (PAAm) gels. These gels were prepared from acrylamide with N,N'-methylenebisacrylamide at various onset temperatures (T-on) by free radical crosslinking copolymerization in water and dried before use for swelling experiments. Transmitted light intensity (I-tr) from the gels increased during early stages when PAAm gels were immersed in water at room temperature and then decreased continuously as swelling time was increased. Decrease in I-tr was attributed to the increase in the scattered light intensity which may originate from the contrast between 'frozen blob clusters' and holes in the swelling gel. Decrease in I-tr was modelled using the Li-Tanaka equation from which time constants (tau(1)) and collective diffusion coefficients (D-0) were determined for the PAAm gels prepared at different onset temperatures. tau(1) and D-0 were found to be dependent on T-on. The correlation between T-on and tau(1) and D-0 was explained in terms of the size of microgels formed during gelation. (C) 2003 Society of Chemical Industry.