The Sliding Behavior Observation And Inquiry Of Droplet On The Surface Of Silicone Polymer

Wetting phenomenon refers to the phenomenon that the droplets contact with the solid material and then spread on the surface,and wetting properties is one of the important properties of the material surface,which are usually measured by water contact angle and sliding angle.The movement pattern of droplet on the solid surface can be divided in wet expansion,adhesion,jumping,slipping,rolling and so on.The properties of solid surface,surface morphology,the viscosity of the liquid droplet will affect the movement pattern of droplet.The interaction between solid surface and droplet can be reduced on the surface of low surface energy which is easy to obtain better hydrophobicity.Fluorine material and silicone material are the nature materials of the lowest energy by present reported.Because of the low cost and good flexibility,the silicone polymeric material has a broad application prospects to achieve particular wettability.In this thesis,a detailed observation and inquiry is carrying on the phenomenon that droplets can slide on the flat surface of silicone polymer,the main work is as follows:1.We observed that the dynamic displacement of water droplets on the typical artificial superhydrophobic surfaces prepared(aluminum substrate with PTES modified)is rolling(Bouncing and rolling),and that dynamic displacement of water droplets on a flat surface of silicone polymer is a sliping motion.2.The dynamic displacement phenomenon is rare reported on the flat fluoropolymer surface,and in this paper we also found it is difficult to observe the dynamic behavior of the displacement of the droplet on a flat surface of the fluoropolymer.But it is able to observe the dynamic displacement phenomenon of droplet on the smooth surface of a silicon-containing polymer at a low sliding angle.In the thesis we prepared silicone polymers of different molecular weight(the molecular structure of the same species,the same reaction)on Al substrate,and then observed the dynamic displacement.3.By testing wetting properties of the silicone polymer surface of different molecular weights,we found that the sliding angle increases with the increasing molecular weight and the sliding phenomenon lost when the molecular weight increased to 550000.After a series of analysis,we conclude that it is the appearance of roughness on the flat surface with the increasing molecular weight that affected the sliding behavior of droplet.