Poly(DMAEMA-co-VP)/Fe_3O_4纳米复合水凝胶的制备及性能

Poly(DMAEMA-co-VP)/Fe_3O_4 Nanocomposite Hydrogels

以甲基丙烯酸-N,N-二甲氨基乙酯(DMAEMA)、4-乙烯基吡啶(VP)为单体,N,N-亚甲基双丙烯酰胺(BIS)为交联剂,在Fe_3O_4纳米粒子分散液中原位共聚制备了具有温度、pH、磁场三重响应性的纳米复合水凝胶。对纳米复合水凝胶的溶胀性能、温敏性、pH敏感性、磁场响应性等性能进行了研究,进而考察了纳米复合水凝胶对重金属离子(Cu^(2+))的吸附脱附行为。结果表明,纳米复合水凝胶具有良好的温敏性、pH敏感性和磁场响应性,并且对重金属离子(Cu^(2+))有可逆的吸附-脱附作用。

PDMAEMA hydrogels were widely investigated due to their unique responsiveness to pH and temperature. Introduction of other components by free radical copolymerization to improve the properties of PDMAEMA hydrogels has become a popular topic. In this work, nanocomposite hydrogels which are responsive to pH, temperature and magnetic field were prepared in-situ in a Fe3O4 nanopartide （Fe3O4 NPs） dispersion, utilizing N,N-dimethylaminoethyl methacrylate （DMAEMA） and 4-vinylpyridine （VP） as monomers, N, N-methylenebis acrylamide （BIS） as crosslinking agent. Due to the existence of PDMAEMA component, the resulting nanocomposite hydrogels exhibit obvious thermosensitivity and pH sensitivity. The pyridine groups in the hydrogel network can form reversible coordination with Cu^2 ＋ for efficient absoption and desorption. At high pH, the coordination between Cu^2＋ and pyridine groups promotes an absorption process, when the pH is lowered, pyridine groups are protonated and desorption of Cu^2＋ occurs. What is interesting, introduction of Fe3O4 NPs into the above mentioned copolyrner hydrogel makes the nanocomvasite hydrogel responsive to magnetic field. This provides an opportunity to utilize the nanocomposite hydrogel as reusable materials for heavy metal ion absorption.