Swelling Rate Analysis of Acrylamide-Based Hydrogels in Distilled Water and Various Solutions and Determination of Diffusion Coefficient

Acrylamide-based hydrogels were synthesised in this study by copolymerisation of acrylamide and bis-acrylamide monomers. The swelling rate of the hydrogels in distilled water and various ionic solutions were measured by weighing the hydrogels during the swelling at various time intervals. The effects of different synthesis parameters such as the density of the cross-linking agent, polymerisation temperature, the amount of reaction initiator, and the presence of various ions within the swelling environment on the swelling behaviour of synthesised hydrogels were studied. The results showed that the density of the cross-linking agent and the concentration of the solution in which the hydrogel swells had the greatest influence on the diffusion mechanism of these hydrogels; to the extent that they transform Fickian diffusion into a non-Fickian one. The calculations showed that the final amount of diffusion coefficient is greater than the one in the end of the first half of swelling.

Keywords:

hydrogel , acrylamide , swelling rate , diffusion mechanism , diffusion coefficient