Abstract
Polyampholyte gels based on 1-vinyl-2-aminoethyl ether (VAEE) and sodium salt of acrylic acid (AANa) were synthesized by γ-initiated radical polymerization. Physicochemical and structural properties of crosslinked polyampholytes have been characterized by elemental analysis, potentiometric titration, gravimetry, IR, NMR, DSC, SAXS and WAXS methods. Amphoteric gels have amorphous structure independently on pH. The amount of non-freezing water and the mesh size of the gel depends on pH being minimal at the isoelectric point (IEP). Structural data have been interpreted in terms of microphase separation phenomenon due to long-ranged electrostatic attraction or repulsion forces. Amphoteric gel mass oscillation and pH oscillation as well as arising of pH gradient within the gel matrix under the externally imposed electric field has been observed The qualitative explanation of oscillation phenomenon is given in terms of interpretation observed for ultrathin polyelectrolyte complex membranes. The formation of pH gradient across the gel sample stimulated by DC electric field is considered from the polarization of gel matrix point of view. The driving force leading to appearance of pH oscillation in polyampholyte gels is also discussed.