Xie Shuting, Chen Sheng, Zhu Qifan, Li Xing, Wang Dan, Shen Shitao, Jin Mingliang, Zhou Guofu, Zhu Yonggang, Shui Lingling
National Center for International Research on Green Optoelectronics, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China.
Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China.
ACS Appl Mater Interfaces. 2020 Jun 10;12(23):26374-26383. doi: 10.1021/acsami.0c05625. Epub 2020 Jun 1.
Janus particles (JNPs) with controlled anisotropies are regarded as promising materials for sophisticated building blocks and assembly. Herein a straightforward method was proposed for the synthesis of uniformly distributed JNPs with controllable anisotropies, showing two compartmental bulbs with different surface wettability. The synthetic strategy is based on the phase separation-induced styrene liquid protrusion on seed poly(styrene--acrylic acid) (CPSAA) nanoparticles via controlled swelling, with the formed polystyrene (PS) and CPSAA compartments corresponding to the amount of monomers. The size (lateral length) ratio of formed PS and CPSAA bulbs, /, defined as "Janusity", has been precisely tuned in the range of 0-0.91 by controlling the mass ratio of two monomers. Obtained JNPs with tunable amphiphilicity are utilized as colloid surfactants to prepare Pickering-emulsions of both water-in-oil (W/O) and oil-in-water (O/W) with proper Janusity. The stability of achieved W/O and O/W Pickering-emulsions is dependent on the adhesion energy of a JNP at the water-oil interfaces. Prepared JNPs have also being utilized to prepare and stabilize monodisperse droplets in microfluidic devices, demonstrating their high potential for fundamental research and practical applications.
具有可控各向异性的Janus粒子（JNPs）被认为是用于精密构建模块和组装的有前途的材料。本文提出了一种直接的方法来合成具有可控各向异性的均匀分布的JNPs，其呈现出具有不同表面润湿性的两个隔室球泡。合成策略基于通过控制溶胀在种子聚（苯乙烯-丙烯酸）（CPSAA）纳米颗粒上相分离诱导的苯乙烯液体突出，形成的聚苯乙烯（PS）和CPSAA隔室与单体的量相对应。通过控制两种单体的质量比，已将形成的PS和CPSAA球泡的尺寸（横向长度）比/定义为“Janus度”，精确调整到0-0.91的范围内。获得的具有可调两亲性的JNPs被用作胶体表面活性剂，以制备具有适当Janus度的油包水（W/O）和水包油（O/W）型Pickering乳液。所制备的W/O和O/W Pickering乳液的稳定性取决于JNP在水-油界面处的粘附能。制备的JNPs还被用于在微流控装置中制备和稳定单分散液滴，证明了它们在基础研究和实际应用中的巨大潜力。
