论文部分内容阅读
系统地研究了亚微米聚苯乙烯微球在气-液界面的组装机理.聚苯乙烯微球在介质对流的带动下会到达悬浮液的表面并在气-液界面组装,气-液界面处聚苯乙烯微球间由弯液面产生的毛细管力是组装的推动力.界面处聚苯乙烯微球在干燥过程中其润湿性发生了转变,由完全润湿到部分润湿并最终变成不润湿,相应的聚苯乙烯微球与分散介质间接触角也逐渐增大.研究表明,只有接触角达到或超过某数值θ′critical时,才能够出现气-液界面组装现象.考虑到PS胶粒晶体的表面是“规则”粗糙的表面,由Wenzel公式知θ′critical大于测量值θ=22°.聚苯乙烯微球润湿性的转变是界面组装发生和持续进行的关键性因素.
The assembly mechanism of submicron polystyrene microspheres at the gas-liquid interface was studied systematically. The polystyrene microspheres reached the surface of the suspension under the convection of the medium and were assembled at the gas-liquid interface and at the gas-liquid interface The capillary force generated by the meniscus between the polystyrene microspheres is the driving force for the assembly.The polystyrene microspheres at the interface change their wettability during the drying process from complete wetting to partial wetting and eventually change The contact angle between the corresponding polystyrene microspheres and the dispersion medium is also gradually increased.Research shows that gas-liquid interfacial assembly can only occur if the contact angle reaches or exceeds a certain value θ’critical. The surface of the PS colloidal crystals is a “regular” rough surface that is θ’critical by the Wenzel formula greater than the measured value θ = 22 °. The shift in the wettability of PS microspheres is a key factor in the occurrence and ongoing interface assembly .