温度敏感型复合结构Janus粒子的制备及自驱动微马达的构建

Preparation of a thermosensitive Janus particle with composite structure and construction of autonomous motor

为了构建自驱动运动的自驱动微马达,采用真空溅镀技术与化学聚合相结合的方法制备了一种具有温度敏感性质的Janus粒子P(MAA-co-DVB)@Pt@PNIPAM,并利用此粒子中不对称分布的Pt催化H_2O_2快速分解的特性,与H_2O_2溶液共同构建了自驱动微马达,以实现纳米粒子在液体中的自驱动运动.其中,具有催化活性的金属Pt被温度敏感的PNIPAM外壳所包裹,使自驱动微马达的运动受到温度变化的影响.此外,利用红外光谱(FTIR)、扫描电镜(SEM)和透射电镜(TEM)对产物的形貌和化学成分进行了表征.还通过带有热台的光学显微镜对自驱动马达的运动进行了实时观测.结果发现:在10%的H_2O_2溶液中,25℃下粒子的运动速率明显高于40℃下的运动速率,证实了粒子在双氧水中的自驱动运动及温度变化对运动的影响.

In order to construct an autonomous micromotor with self-driven movement, a thermosensitive Janus particle P(MAA -co -DVB)@Pt@PNIPAM was synthesized by the combination of vacuum sputtering and chemical polymerization. By virtue of the property of fast decomposition of H2O2 catalyzed by the asymmetrically distributed Pt, this particle can be used to build an autonomous micromotor by adding H2O2 aqueous solution as the fuel. This micromotor can realize a self-driven movement in the particular liquid. Herein, the catalytically active Pt was covered by the thermosensitive PNIPAM shell, which affected the movement of autonomous motors by altering the system temperature. Furthermore, Fourier transform infrared spectroscopy(FTIR), scanning electron microscope (SEM) and transmission electron microscope(TEM) were performed to determine the morphology and chemical composition of the synthesized Janus particle. Meanwhile, the movement of the autonomous micromotor was in situ observed by the optical microscopy in the hot and cold stages. It is obvious that the Janus particles moved in one direction when the H2O2 was added into the system, and the velocity of the Janus particles became much smaller when the temperature increased from 25 ℃ to 40 ℃ in 10% H2O2 aqueous solution.