Department of Chemical Engineering (BK21 FOUR Integrated Engineering Program), Kyung Hee University, Yongin 17104, South Korea.
Department of Chemical Engineering (BK21 FOUR Integrated Engineering Program), Kyung Hee University, Yongin 17104, South Korea.
J Colloid Interface Sci. 2022 Dec;627:375-384. doi: 10.1016/j.jcis.2022.07.055. Epub 2022 Jul 15.
A solvent evaporation-induced phase separation method, which is based on the preferential partitioning of two or more immiscible materials after solvent evaporation on providing heat, has been one of the main strategies for synthesis of Janus particles (JPs). Considering this approach, it should be possible to synthesize surfactant free-JPs in continuous flow by the ultrasonic nebulizer spray method.
Two polymers, polystyrene and polymethylmethacrylate, were dissolved in dichloromethane, and droplets of a precursor solution generated by an ultrasonic nebulizer were then conveyed through a borosilicate glass cylinder with two heating zones. The solvent evaporation-induced phase separation occurred in a single flow process, which resulted in the preferential partitioning of two incompatible polymers in the droplets, leading to the formation of the spherical bicompartmental JPs.
The successful fabrication of spherical JPs was observed at high polymer concentrations (1.5 and 2.0 wt%), and at elevated temperature (40-75 °C). The fluorescent compartmentalization of JPs was confirmed. Furthermore, the interfacial arrangement of JPs at oil-water interface was studied. A detailed explanation of theoretical prediction of interfacial configurations of JPs was provided. Lastly, the generated JPs were proved as Pickering stabilizers at the oil-water interface.
溶剂蒸发诱导相分离方法是基于溶剂蒸发后提供热量时两种或多种不混溶材料的优先分配，这是合成 Janus 粒子 (JP) 的主要策略之一。考虑到这种方法，应该有可能通过超声雾化器喷雾法在连续流中合成无表面活性剂的 JP。
两种聚合物，聚苯乙烯和聚甲基丙烯酸甲酯，溶解在二氯甲烷中，然后通过超声雾化器生成的前驱体溶液的液滴被输送通过具有两个加热区的硼硅酸盐玻璃圆柱。溶剂蒸发诱导相分离在单个流动过程中发生，导致两种不混溶聚合物在液滴中优先分配，从而形成球形双隔室 JP。
在高聚合物浓度（1.5 和 2.0wt%）和升高的温度（40-75°C）下观察到球形 JP 的成功制造。证实了 JP 的荧光分隔。此外，研究了 JP 在油水界面处的界面排列。提供了对 JP 界面构型理论预测的详细解释。最后，证明生成的 JP 是油水界面的 Pickering 稳定剂。
