Zhang Qilu, Dong Renfeng, Chang Xueyi, Ren Biye, Tong Zhen
College of Materials Science and Engineering, South China University of Technology , Guangzhou 510640, China.
ACS Appl Mater Interfaces. 2015 Nov 11;7(44):24585-91. doi: 10.1021/acsami.5b06448. Epub 2015 Nov 2.
The controlled self-assembly of self-propelled Janus micromotors may give the micromotors some potential applications in many fields. In this work, we design a kind of SiO2-Pt Janus catalytic micromotor functionalized by spiropyran (SP) moieties on the surface of the SiO2 hemisphere. The spiropyran-modified SiO2-Pt Janus micromotor exhibits autonomous self-propulsion in the presence of hydrogen peroxide fuel in N,N-dimethylformamide (DMF)/H2O (1:1 in volume) mixture. We demonstrate that the self-propelled Janus micromotors can dynamically assemble into multiple motors because of the electrostatic attractions and π-π stacking between MC molecules induced by UV light irradiation (λ = 365 nm) and also quickly disassemble into mono motors when the light is switched to green light (λ = 520 nm) for the first time. Furthermore, the assembled Janus motors can move together automatically with different motion patterns propelled by the hydrogen peroxide fuels upon UV irradiation. The work provides a new approach not only to the development of the potential application of Janus motors but also to the fundamental science of reversible self-assembly and disassembly of Janus micromotors.
自驱动的Janus微马达的可控自组装可能会使微马达在许多领域具有一些潜在应用。在这项工作中，我们设计了一种SiO₂-Pt Janus催化微马达，其在SiO₂半球表面通过螺吡喃（SP）部分进行功能化。螺吡喃修饰的SiO₂-Pt Janus微马达在N，N-二甲基甲酰胺（DMF）/H₂O（体积比1:1）混合物中存在过氧化氢燃料的情况下表现出自主自推进能力。我们证明，由于紫外线照射（λ = 365 nm）诱导的MC分子之间的静电吸引力和π-π堆积，自驱动的Janus微马达可以动态组装成多个马达，并且当首次将光切换为绿光（λ = 520 nm）时也会迅速分解为单个马达。此外，组装好的Janus马达在紫外线照射下可以在过氧化氢燃料的推动下以不同的运动模式一起自动移动。这项工作不仅为Janus马达潜在应用的开发提供了一种新方法，也为Janus微马达可逆自组装和解组装的基础科学提供了新方法。
