Dynamic mechanical properties and swelling of UV-photopolymerized anionic hydrogels

The tensile dynamic mechanical properties and weight degree of swelling for anionic 2-hydroxyethyl methacrylate-co-acrylic acid hydrogels were observed. Fabrication parameters examined were UV-photopolymerization exposure time, UV-photopolymerization intensity, and weight percentage crosslinker. The environmental conditions tested were electrolyte compositions of 0.5 and 0.05 M potassium hydroxide under applied frequencies of 0.1, 1, or 10 Hz. The overall maximum and minimum storage modulus was 1.83 +/- 0.18 MPa and 68.5 +/- 7.2 kPa, respectively, loss modulus was 432 +/- 63 and 7.67 +/- 3.22 kPa, respectively, and weight degree of swelling was 14.27 +/- 1.27 and 1.95 +/- 0.33, respectively. The morphology of fabricated hydrogels was examined using scanning electron microscopy showing a range of porous structures over the fabrication and environmental conditions examined, accounting for the variation in mechanical properties. The properties examined are of interest to researchers fabricating, designing, or modeling active hydrogel-based microfluidic components. (c) 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012