EFFECT OF pH ON SWELLING PROPERTIES OF COMMERCIAL POLYACRYLIC ACID HYDROGEL BEAD

The widespread application of hydrogels bead in a number of application like separation, adsorption, filtration, agriculture and drug delivery make it important to property understand the swelling properties of these materials. Typically, gel size and swelling capacity are sensitive to outer solution pH. In this paper, the study of the swelling capacity of the commercial polyacrylic acid hydrogel bead was investigated as a function of time and pH. The diameter, weight, degree of swelling, water retention as well as the fractional hydration were studied to predicate the swelling properties of hydrogel bead at a given pH. The type of diffusion and its related parameter diffusion exponent (n) and diffusion constant (k) were studied and calculated.