具有高临界溶胀温度纳米复合凝胶的辐射合成及其近红外光响应性研究

Near-infrared ligh (NIR light, 650-1000 nm) has an intense heating effect, which is widely used for photothermal therapy in clinical applications. As compared to UV or visible light, NIR light is less detrimental to healthy cells and can have a deeper penetration through tissue. The nanoparticles (e.g., gold, carbon nanotubes) can absorb NIR light and generate heat. This unique ability to remotely heat the nanocomposites allows for their remote controlled (RC) applications, including the ability to remotely drive the polymer through a transition event (e.g., swelling transition). Based on these characteristics, some NIR-sensitive “heater” substance such as nano-gold were doped into thermally responsive hydrogels to improve the photothermal effect. Here, we will fabricate a simple and environmentally friendly route for the preparation of nanocomposite hydrogels by incorporating HAuCl4•H2O、carbon nanotubes、graphene oxide into a monomer solution followed by γ -radiation polymerization. The composite hydrogel can be self-heating on exposure to an NIR laser and, consequently, can display swelling transitions. This UCST-type hydrogel will extend the applications of thermo-responsive polymers. As an example of applications, the nanocomposite hydrogel as drug carriers will be demonstrated to control drug release remotely by the use of an NIR laser.

近红外光（NIR light，650-1000 nm）具有很强的热效应，近年来在光热疗法等医学领域具有广泛的应用。据报道，纳米金颗粒、碳纳米管等纳米材料能够吸收近红外光、将其转换为热能并传递给周围的环境。这种独特的光热效应可以用来构建近红外光远程控制体系，如在温敏性凝胶中掺杂对近红外光敏感的纳米金等材料而制备纳米复合凝胶，即可实现对凝胶相变行为的远程控制。本课题拟设计合成一系列季铵盐功能单体，然后将这些单体与氯金酸、碳纳米管、氧化石墨烯等水溶液通过辐射交联法原位合成一系列具有较高临界溶胀温度（UCST）的纳米复合凝胶。通过引入对近红外光具有强吸收的纳米金颗粒等纳米材料，利用其独特的光热效应将光刺激转变为热响应，实现近红外光对凝胶负载药物的远程控制释放，从而发展一种具有近红外响应性的纳米复合水凝胶。这类高温下溶胀、低温下收缩的UCST凝胶将进一步拓展响应性水凝胶在医疗领域中的应用。

响应性凝胶是一类重要的响应性聚合物材料。本课题拟设计合成一系列功能单体，然后将此单体与氯金酸、碳纳米管、氧化石墨烯等水溶液原位聚合为一系列具有较高临界溶胀温度（UCST）的纳米复合凝胶。一方面，我们采用N,N-二乙氨基甲基丙烯酸乙酯（DEAEMA）、二甲基氨基丙基甲基丙烯酰胺（DMAPMA）为响应性单体，设计制备了一系列具有二氧化碳响应性的聚合物组装体，包括微凝胶、乳液、功能表面等，通过二氧化碳刺激源的引入和移除，可实现其功能的有效调节。在微凝胶体系，功能调节表现为凝胶的溶胀和收缩；在乳液体系，表现为乳液内部结构的调节，从高内相乳液-水包油乳液逐渐转变；在功能表面体系，引入二氧化碳可以使表面亲水化，实现功能器件在水中的下潜。另一方面，我们设计合成了具有光催化等功能的纳米材料，并与功能单体原位聚合制备聚合物杂化凝胶材料，此部分工作纳米材料设计制备部分已基本完成。在本课题(21404008)的资助下，我们总结相关研究成果，发表SCI论文4篇，并有1篇待发表，基本完成了预期目标。