| The superhydrophobic surface has very low adhesion and strong self-cleaning properties,and is more adaptable than super hydrophobic surfaces in the face of complex pollution.The methods of preparing super double sparse surface by many researchers are concentrated on the chemical or electrochemical methods such as sol-gel,phase separation,anodic oxidation and so on.These methods are difficult to be popularized in actual production because of the shortcomings of complex process and low forming area.Micro nano thermal press printing is a new micro nano processing method in recent years.It has the advantages of good precision,high efficiency,low cost and large area.However,there are few studies on the preparation of hydrophobic materials by micro nano thermal embossing.In this paper,microstructures with super hydrophobic/oil repellent effects were successfully constructed on PE composite films by micro nano thermal press and low surface energy modification.The forming principle,process parameters and weatherability of complex environment were discussed.The influence of process parameters on surface morphology and hydrophobic effect was emphatically analyzed.It provides a valuable reference for further preparation of super hydrophobic materials.The main contents and results are as follows:The microstructure of superhydrophobic and oil repellent properties was prepared on the surface of PE composite film by using micro nano hot embossing method and using filter screen as mould.The contact angle of the final product to water is 154 degrees,the rolling angle is 1 degrees,the contact angle of soybean oil reaches 97 degrees.If fluorsilane is used to modify the contact angle,the contact angle of soybean oil can be further increased to 140 degrees,and the time of hot embossing is also within 20s.A layer of SiO-2 microsphere hydrophobic layer was prepared on the surface of PE composite film by adding SiO 2 microspheres to hot embossing.The contact angle of the surface was 153 degrees and the rolling angle was 1 degrees.The contact angle of the sample to oil was 135 degrees after fluoro silane modification,and the effect of super hydrophobic and oil thinning was achieved.In the electron microscope,it is found that SiO 2 microspheres are not only distributed on the surface of the material,but are mixed with PE in the process of hot embossing,and the products have good hydrophobicity and good weatherability.The methods of improving the contact angle of the polymer surface by two kinds of soft etching are the microcolumn array and the common commercially available gold phase sand paper.In the experiment,PDMS spin is applied to the surface of the micro column array template,and after being solidified,the soft template is uncovered.The soft template surface presents a large number of irregular nano pits.Subsequently,UV nano imprint technology was used to reproduce the microstructure on the surface of PDMS soft template with UV glue,and then the surface was modified by the fluorosilane with low surface energy,and the hydrophobic ity of the surface of the UV adhesive was improved.Because of the decrease of the duplication accuracy of the structure,the roughness of the surface of the UV adhesive is low,so there is still a gap between the hydrophobic effect and the super hydrophobic ity.The metallographic sand paper is used as the parent plate,and PDMS is used to spin it directly.After curing,it is found that the surface of the PDMS sample has a fractal structure similar to that of the metallographic sand paper,and the super hydrophobic effect has been achieved after the modification of the low surface material.In the experiment,it was found that PDMS duplicated the microstructure of metallographic sand paper with high precision,and the surface of PDMS would also form a micro-Nano-two-stage composite structure,which greatly improved the hydrophobic ity of the sample.At the same time,this process only needs a single turn over,simplifying the operation process and reducing the production difficulty and cost. |
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