Polyacrylamide (PAAm) hydrogels were synthesized by acrylamide polymerization in lyotropic liquid crystal (LLC) phase formed by surfactant Brij 58 solution. The morphology, structure and swelling property of the hydrogels were characterized. SEM images showed that photopolymerization of acrylamide monomers in organized assemblies with concentration between 10% and 40% formed highly ordered hydrogels. The pore size of the LLC hydrogels was 1～2 µm, which was about one fortieth of that of the traditional hydrogel. Phase reversal and phase separation occurred when concentration of Brij 58 was higher than 50%. Porosity of the hydrogels decreased with the increase of Brij 58 concentration. Characteristic peaks of FTIR spectra corresponding to carbonyl and amino groups shifted to lower wavenumber, indicating that more inter-molecular hydrogen bonds in LLC PAAm hydrogels. The LLC hydrogel kept the characteristic feature of sensitivity to pH as traditional hydrogel and a higher swelling ratio could be achieved.

Key words: polyacrylamide, lyotropic liquid crystal (LLC), hydrogel, swelling ratio