Research On The Preparation And Process Of Polymer Functional Surface Microstructure Based On Ultrasonic Imprinting Technology

With the development of biomimetic technology,it has been realized that the excellent surface hydrophobicity of rose-petal,butterfly wing,mosquito compound eye are closely related to its microstructure and surface chemical composition.In recent years,the preparation and construction technology of hydrophobic functional surface has become a research hotspot at home and abroad because of its wide application prospect in realizing self-cleaning,anti-corrosion,deicing and drag reduction of materials.Ultrasonic precision embossing technology is a kind of material surface functional microstructure preparation technology that has been paid attention to in recent years.It has advantages such as high molding efficiency,low energy consumption and small heat affected area,etc.However,the research and application of this technology in the preparation of hydrophobic microstructure is not yet in-depth.Based on the surface wetting theory,a series of hydrophobic microstructures with different sizes were fabricated on the surface of aluminum alloy plate by laser processing and the surface was used as embossing mold.The hydrophobic microstructure on the metal surface was transferred to the surface of PET polymer film by ultrasonic embossing technology,so as to investigate the effect of main parameters of ultrasonic embossing technology on the replication ratio and hydrophobicity of hydrophobic structure on PET surface,establish a general method for process optimization and hydrophobicity prediction.At the same time,the basic guidance of hydrophobic mold design was established.To this end,the following research work was carried out:(1)Based on Wenzel model and Cassie model,the hydrophobicity of linear,square and dot microstructure with different sizes on the surface of aluminum alloy was analyzed.On this basis,a series of hydrophobic microstructures with different sizes were produced by laser processing technology.Through the contact angle test,the variation law of surface hydrophobicity under different geometric parameters was investigated,and the applicability of Wenzel model and Cassie model was judged by combining experimental and theoretical analysis.(2)With Branson 2000 X ultrasonic plastic welding machine as the core,a precise ultrasonic embossing experimental system was built,a mold mounting platform and a PET polymer film compression mechanism were designed,and a series of embossing experiments were carried out for PET film with thickness of 0.5mm.By observing the surface hydrophobicity and microstructure replication of PET film,the influence of three main parameters of ultrasonic embossing force,embossing time and holding time were investigated.(3)Three factors and five horizontal orthogonal experiments were used to analyze the optimum technological parameters of different hydrophobic structures.Combining range analysis and analysis of variance(AVOAN),the aim is to evaluate the influence of each process parameter on the hydrophobicity of the specimen surface,and to establish the optimal process parameter combination.(4)The structural complementarity between the mold and the specimen was analyzed.The general rule between mold hydrophobicity and PET specimen hydrophobicity was investigated.(5)BP and RBF neural networks were used to build the prediction model of hydrophobicity on the surface of the PET specimen,to predict the contact angle of the specimen under different process parameters.At the same time,the predictive performance of the two networks is analyzed and compared.