Macromolecular Rapid Communications, Vol.21, No.4, 174-177, 2000
Swelling behavior of poly(acrylic acid) gels in aqueous ethanol -effects of counterion species and ionic strength
The swelling behavior of poly(acrylic acid) (PAA) gels in aqueous ethanol (EtOH) was investigated. These gels were prepared by gamma-irradiation pretreated in aqueous solutions of different pH levels in order to vary the charge density. With increasing pH of the pretreating solutions, a distinct collapse was observed for a PAANa gel in 40-60 vol.-% EtOH. This effect was less pronounced in the presence of 0.1 M NaCl. Moreover, the deswelling regions were dependent on the counterion species of the used salt solutions, i.e. NaCl or CsCl.