Medium Effect on Swelling and Sorption Behaviour of Sodium Chloride from-and-into Poly(vinyl alcohol)-Glutaraldehyde Hydrogel at Room Temperature

This work aims to study the swelling behaviour of poly(vinyl alcohol)-glutaraldehyde (PVA/GA) hydrogel under various acidity and NaCl concentration of medium and release behaviour of NaCl from PVA/GA hydrogels. The hydrogels were characterized by FT-IR and SEM techniques. Repeated washing was necessary to produce a residual-free PVA/GA hydrogel. The FTIR spectra demonstrated that the incorporation of NaCl into the PVA/GA hydrogel did not result in specific interactions. The swelling profile of PVA/GA at the different pH medium was due to protonation and charge screening effects, while its swelling behaviour at various salt concentrations in medium was associated with the charge screening and osmotic pressure effects. The kinetic profile of NaCl absorption and desorption from-and-into PVA/GA was presumed to be controlled by the physical properties of hydrogel such as porosity, cavity and characteristic of the hydrodynamic radii of NaCl.