Li Yifan, Dekel Dario R, Manor Ofer
The Wolfson Faculty Department of Chemical Engineering, Technion─Israel Institute of Technology, Haifa 3200003, Israel.
The Nancy & Stephen Grand Technion Energy Program (GTEP), Technion Israel Institute of Technology, Haifa 3200003, Israel.
ACS Appl Mater Interfaces. 2021 Dec 15;13(49):59471-59477. doi: 10.1021/acsami.1c17778. Epub 2021 Dec 1.
We demonstrate the application of a 20 MHz frequency surface acoustic wave (SAW) in a solid substrate to render its surface "self-cleaning", redirecting the deposition of precipitating mass onto a nearby inert substrate. In our experiment, we confine a solution of poly(methyl methacrylate) polymer and a volatile toluene solvent between two substrates, lithium niobate and glass, at close proximity. We render the glass surface low energy by employing hydrophobic coating. In the absence of SAW excitation, we observe that the evaporation of the solvent yields polymer coating on the higher energy lithium niobate surface, while the glass surface is mostly devoid of polymer deposits. The application of a propagating SAW in the lithium niobate substrate mitigates the deposition of the polymer on its surface. As a response, we observe an increase in the deposition of the polymer precipitates on glass. Above a SAW power threshold, the polymer appears to deposit solely on glass, leaving the surface of the lithium niobate substrate devoid of polymer mass.
我们展示了在固体衬底中应用20MHz频率的表面声波（SAW），以使衬底表面具有“自清洁”功能，即将沉淀物质的沉积重新引导至附近的惰性衬底上。在我们的实验中，我们将聚甲基丙烯酸甲酯聚合物溶液和挥发性甲苯溶剂置于两块紧密靠近的衬底（铌酸锂和玻璃）之间。我们通过使用疏水涂层使玻璃表面具有低能量。在没有SAW激发的情况下，我们观察到溶剂蒸发会在能量较高的铌酸锂表面产生聚合物涂层，而玻璃表面几乎没有聚合物沉积。在铌酸锂衬底中施加传播的SAW可减轻聚合物在其表面的沉积。相应地，我们观察到玻璃上聚合物沉淀物的沉积增加。在SAW功率阈值以上，聚合物似乎仅沉积在玻璃上，铌酸锂衬底表面没有聚合物物质。
