Radiation Induced Synthesis of 2‐Hydroxyethylmethacrylate‐co‐ Vinylbenzyltrimethylammonium Chloride Binary Hydrogel System‐II: Dynamic Swelling Studies

2‐Hydroxyethylmethacrylate‐co‐vinylbenzyltrimethylammonium chloride (HEMA‐co‐VBT) hydrogels were synthesized using ⁶⁰Co gamma radiation. The dynamic swelling of the binary hydrogel system was investigated gravimetrically. The morphology and pore structure of various gels was studied using scanning electron microscopy (SEM). Incorporation of ionic monomer VBT into the HEMA gel matrix resulted in a highly porous structure. Effect of various experimental variables like gel composition, temperature of the swelling medium, ionic strength, presence of biologically important additives (Glucose, Urea), surfactants (Triton‐X, 7‐Deoxycholic acid) and monovalent anionic dyes acid blue 25 (AB25), acid yellow 99 (AY99) and Congo red (CR) on swelling kinetics of hydrogels has been reported. The dynamic swelling parameters such as swelling exponent (n), diffusion coefficient (D) and mean swelling time (MST) were evaluated and the possible transport mechanism has been suggested. The activation energy for diffusion (E _D ) of water into gels was evaluated to be 15‐40 kJmole⁻¹.

Keywords:

• gamma radiation
• 2‐hydroxyethyl methacrylate
• vinylbenzyltrimethyl ammonium chloride
• hydrogels
• dynamic swelling
• Fickian
• anomalous

Acknowledgements

The authors wish to thank Dr. S. K. Gupta, Dr. A. Singh, and Mr. Tinharen of TPPED, BARC for providing help in SEM analysis.