Tsumura Yusuke, Oyama Keigo, Fameau Anne-Laure, Seike Musashi, Ohtaka Atsushi, Hirai Tomoyasu, Nakamura Yoshinobu, Fujii Syuji
Division of Applied Chemistry, Environmental and Biomedical Engineering, Graduate School of Engineering, Osaka Institute of Technology, 5-16-1 Omiya, Asahi-ku, Osaka 535-8585, Japan.
Université Lille, CNRS, INRAE, Centrale Lille, UMR 8207─UMET─Unité Matériaux et Transformations, F-59000 Lille, France.
ACS Appl Mater Interfaces. 2022 Sep 14;14(36):41618-41628. doi: 10.1021/acsami.2c12681. Epub 2022 Aug 31.
In this study, we report on the fabrication of photo/thermo dual stimulus-responsive liquid marbles (LMs) that can be disrupted by light irradiation and/or heating. To stabilize the LMs, we synthesized micrometer-sized stearic acid (SA) particles coated with overlayers of polypyrrole (PPy) by aqueous chemical oxidative seeded dispersion polymerization. The SA/PPy core-shell particles could adsorb at the air-water interface to stabilize LMs by rolling water droplets on the particle powder bed. The presence of SA, known as a phase-change material, which undergoes a transition from solid to liquid by heating, and PPy, which can transduce light to heat, gives rise to the photo and thermo dual stimulus-responsive characters of the LMs. The disruption of the LMs could be induced in a cascade manner: light irradiation on the LM induced a temperature increase, followed by melting of the SA component on the LM surface, leading to its disruption and release of the inner water. The disruption time is linked to the PPy loading and light irradiation power, and it can be tuned from quasi-instantaneous to a few tens of seconds. The melting of SA due to a light-induced phase change from the solid to liquid state is a new mechanism to trigger the disruption of LMs. We finally demonstrated two applications of the LMs as a light-responsive microreactor and a sensor.
在本研究中，我们报道了可通过光照射和/或加热破坏的光/热双刺激响应性液滴弹珠（LMs）的制备。为了稳定液滴弹珠，我们通过水相化学氧化种子分散聚合法合成了包覆有聚吡咯（PPy）覆盖层的微米级硬脂酸（SA）颗粒。SA/PPy核壳颗粒可吸附在气-水界面，通过在颗粒粉末床上滚动水滴来稳定液滴弹珠。作为相变材料的SA，通过加热会从固态转变为液态，以及能够将光转化为热的PPy的存在，赋予了液滴弹珠光和热双刺激响应特性。液滴弹珠的破坏可以以级联方式诱导：对液滴弹珠进行光照射会导致温度升高，随后液滴弹珠表面的SA成分熔化，导致其破坏并释放内部的水。破坏时间与PPy负载量和光照射功率有关，并且可以从准瞬时调整到几十秒。SA由于光诱导的从固态到液态的相变而熔化是触发液滴弹珠破坏的一种新机制。我们最终展示了液滴弹珠作为光响应微反应器和传感器的两种应用。
