Moo James Guo Sheng, Wang Hong, Pumera Martin
Division of Chemistry & Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371 (Singapore), Fax: (+65) 6791-1961.
Chemistry. 2016 Jan 4;22(1):355-60. doi: 10.1002/chem.201503473. Epub 2015 Nov 3.
Self-propelled miniaturized machines harness the chemical potential of their environment for movement. Locomotion of chemically powered micromotors have been hugely dependent on the surroundings. The use of pH to alter the mobility of micromotors is demonstrated in this work through the manipulation of hydrogen peroxide chemistry in different acidity/alkalinity. The sequential addition of sodium hydroxide to increase the pH of the solution led to a consequent increase in activity of micromotors. Meanwhile, addition of hydrochloric acid compromised the structural integrity of the microstructures, culminating in locomotive changes. Such dramatic changes in activity and velocities of the micromotors allow the usage of this behavior for pH detection. This concept was illustrated with Janus silver micromotors and tubular bimetallic Cu/Pt micromotors. Alteration of pH serves as a useful general strategy for increasing hydrogen peroxide decomposition for enhanced oxygen-bubble propulsion in catalytic micromotors.
自驱动微型机器利用其周围环境的化学势来实现运动。化学驱动的微电机的运动在很大程度上依赖于周围环境。在这项工作中，通过在不同酸碱度下操纵过氧化氢化学，展示了利用pH值来改变微电机的移动性。依次添加氢氧化钠以提高溶液的pH值，导致微电机的活性随之增加。同时，添加盐酸会破坏微结构的结构完整性，最终导致运动变化。微电机活性和速度的这种显著变化使得可以利用这种行为进行pH检测。这一概念通过Janus银微电机和管状双金属Cu/Pt微电机得到了说明。改变pH值是一种有用的通用策略，可用于增加过氧化氢分解，以增强催化微电机中的氧气泡推进。
