纳米复合模板水凝胶的制备及其性能

Preparation and Characterization of Nanocomposite Hydrogels with a Template Structure

以非离子表面活性剂聚氧乙烯(20)鲸蜡醇醚(Brij58)为模板, 采用自由基聚合制备得到聚(N-异丙基丙烯酰胺)/Brij58/粘土纳米复合模板水凝胶(PLH). 相比于传统纳米复合水凝胶, PLH水凝胶力学性能与亲水性明显改善. 场发射扫描电镜(FESEM)结果表明: Brij58的引入导致传统纳米复合水凝胶的孔洞数量增加, 孔与孔相互贯穿, 大孔结构更加规整, 大孔之间由众多小孔连接. 拉伸应力-应变、储能模量和溶胀动力学研究结果表明, 断裂应力、断裂负载和断裂伸长率随Brij58含量的增加呈先增加后降低的趋势, 然而水凝胶储能模量与最大溶胀度随Brij58含量的增加而增加. 同时, 表面接触角结果表明: 由于Brij58的模板作用和Brij58同粘土之间的吸附作用, 使PLH水凝胶表面接触角先增大后减小.

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.