J. Shan et al., INFLUENCE OF DIFFERENT MEDIA ON MICROMORPHOLOGY OF RADIATION SYNTHESIZED POLY(ACRYLAMIDE SODIUM ACRYLATE) HYDROGELS, Polymer Journal, 30(7), 1998, pp. 585-588
Poly(acrylamide-sodium acrylate) hydrogels were synthesized by Co-60-g
amma ray radiation polymerization in aqueous solutions. The micromorph
ology of hydrogel samples dehydrated in the different alcohol media su
ch as methanol, ethyl alcohol, n-propyl alcohol, iso-propyl alcohol, a
nd tert-butyl alcohol was observed by scanning electron microscope (SE
M). The critical concentrations at volume phase transition of the hydr
ogels in the different alcohol medium-water solutions were obtained. T
he results indicate that the hydrogel samples dehydrated in methanol a
nd in ethyl alcohol display bubble-film network structures, and those
in il-propyl alcohol and in iso-propyl alcohol and in tert-butyl alcoh
ol demonstrate the porous structures including the dense phase. The re
ason is discussed from the critical concentrations and solubility para
meters of different alcohol media.