半草莓结构Janus粒子的制备及可控自驱动微马达的构建

Janus particles, due to the asymmetric structures, exhibit very distinct properties compared to symmetric particles and give promising prospects on the applications of many areas, such as the selective molecular recognition, drug delivery, induced self-assembly and autonomous motors, which therefore have attracted significant attentions in recent years. This project is devoted to the synthesis of stimuli-responsive Janus particles with half-raspberry-like structures，which can further be used for the construction of the controllable autonomous micromotors..The principle of the directed motion of autonomous micromotors is the fuel decomposition catalyzed by the catalysts, which are asymmetrically distributed on or inside the Janus particles. The resulting bubbles or product-induced concentration gradient will propel the movement of particles..The motion control is an important requirement for future applications of Janus particles. Herein，temperature-responsive monomers and magnetic nanoparticles will be introduced into the system during the synthesis of stimuli-responsive Janus particles, which can tune the velocity and direction of the motion by changing the temperature and magnetic field synergistically. Especially, the precursor particle will be prepared with the method of combining the distillation-precipitation polymerization and the sol-gel process, which can produce the monodispersed microspheres with multi-shell smart structures. The accurate control of morphology of the precursor particles will provide the excellent opportunity to produce the uniform Janus particles, which is a necessity to construct advanced structures of Janus particles.

Janus粒子是一类具有不对称结构的粒子，它们的不对称性使其拥有均一粒子所不具备的特殊性质，在选择性分子识别、药物释放、诱导自组装和自驱动马达等领域具有非常广阔的应用前景，已成为高分子学科的研究热点之一。本项目拟制备具有环境刺激-响应性质的半草莓结构Janus粒子，并以此为基础构建可控的自驱动马达。Janus粒子上不对称分布的催化剂组分可以催化局部的‘燃料’分子进行降解，从而产生气泡或产物引起的浓度梯度，推动粒子进行运动，构建出自驱动马达。其中对自驱动微马达运动的控制是决定其进一步发展应用的关键问题之一。这里拟在合成过程中引入温度响应单体和磁性粒子，通过温度和磁场的双重控制,实现对微马达运动速率和方向的有效控制。同时，通过蒸馏沉淀聚合与溶胶-凝胶法相结合的方法，构建多壳层结构的单分散微球作为母体粒子，以达到对Janus粒子形态和结构的精准控制，满足其进一步构建高级功能结构的要求。

Janus粒子是一类具有不对称结构的粒子，它们的不对称性使其拥有均一粒子所不具备的特殊性质，在水体修复、药物释放、诱导自组装等领域具有非常广阔的应用前景，已成为目前的研究热点之一。Janus粒子的制备方法有很多，本项目将能大量制备Janus粒子的Pickering乳液法与其它几种简单方法相结合，制备了尺寸可控的多种不同形貌和性质的Janus粒子，包括：不同粒径半树莓形Janus粒子、磁性半草莓Janus粒子、单侧孔道Janus微囊和蘑菇形Janus粒子。本项目还成功制备了温度敏感型和磁性Janus粒子，并基于此构建了自驱动马达。与此同时还初步研究了温敏性质对自驱动马达运动速率的影响。