Preparation and Characterization of Nanocomposite Hydrogels with a Template Structure

Using a nonionic surfactant detergent polyoxyethylene 20 cetyl ether(Brij58) as a template,poly(N-isopropylacrylamide)/Brij58/clay nanocomposite hydrogels(PLH) with a template structure were prepared by free radical polymerization.By comparison with traditional nanocomposite hydrogels the mechanical properties and the hydrophilicity of the PLH hydrogels improved significantly.The result of field-emission scanning electron microscopy(FESEM) showed that the introduction of Brij58 increased the number of pore structures and the interpenetration of the pores.Furthermore,the pore structure was well-defined and connected through many smaller pores.The results of tensile stress-strain,storage modulus,and swelling kinetics showed that the strength,the load,and the elongation at the break increased initially and then decreased with an increase in the Brij58 content,while the storage modulus and the maximum degree of swelling increased with an increase in the Brij58 content.In addition,the obtained surface contact angle showed that because of the effect of the Brij58 template and the adsorption between Brij58 and the clay the surface contact angles of the PLH hydrogels increased initially and then decreased.