Abstract: | To develop a transparent poly(vinyl alcohol) (PVA) hydrogel with high water content and high strength, we studied the physical gelation of PVA solutions and found that low temperature crystallization of PVA solutions in mixed solvents consisting of water and a water-miscible organic solvent yields transparent gels. The strength and transparency of the PVA hydrogel is dependent on both the type of organic solvent and the mixing ratio of water/organic solvent. A mixed solvent from water/dimethyl sulfoxide resulted in the highest transparency and the highest tensile strength among the water/organic solvent combination studied. A plausible mechanism is proposed for the formation of transparent and strong hydrogels on the basis of the results obtained. |