Superhydrophobic Mechanism Of Biomimetic Prototype And 3D Printing Fabrication

Superhydrophobic surface is the solid surface with static contact angle larger than150° and a rolling angle less than 10°,and it widely use in self-cleaning,anti-corrosion,ice suppression,ship drag reduction and other engineering fields.In the preparation process,the rough surface is modified by low energy materials or constructing micro-nanostructure on low energy materials surface.In order to solve the problems in the research of superhydrophobic surface,such as the problem of the old bionic prototype,the insufficient revelation of wetting mechanism and the inability to design the structure arbitrarily in the preparation process,the following study was carried out:(1)The surface wettability of the slippery zone of Nepenthes was measured by using a video optical contact angle meter(CA,SA).The 3D model was constructed by obtaining the morphology parameters and morphology distribution parameters of the composite structure in the slippery zone(Lunate cell,Wax crystal).(2)A dynamic contact angle mathematical model was constructed based on the three-dimensional model and the law of conservation of energy.Based on Wenzel model,Cassie-Baxter model and a coefficient,a mathematical model of static contact angle is established for different infiltration degree of Nepenthes slippery zone.The effects of structural parameters and morphological distribution parameters on the wetting properties of anisotropic superhydrophobic materials were investigated by controlling variables.(3)Based on the minimal energy principle,the infiltration process of ultrapure-water droplet to the Nepenthes slippery zone was numerically simulated with the Surface Evolver software,and the contact angle of ultrapure-water droplet under different infiltration degreewasobtained.Through comparative analysis,the infiltration rate of droplets on the micro nano composite structure in the slip zone of Nepenthes was obtained.(4)The micrometre lunate of the isotropic/anisotropic superhydrophobic sample was fabricated under femtosecond laser 3D printing processing method by photosensitive materials,and graphene coating was used to construct nano scale wax crystal layer.The superhydrophobic wettability of the machined surface was measured by contact angle measuring instrument.The research supplies theoretical foundation for fully revealing the superhydrophobic mechanism of Nepenthes slippery zone,which can promote the Nepenthes slippery zone to become a biomimetic prototype used to design superhydrophobic materials,and provides a potential method for quantitative characterization of infiltration degree produced by liquid droplet to micro-nano structure of superhydrophobic surface.It also proves that femtosecond laser 3D printing technology can be used as an effective processing method for superhydrophobic surface with high efficiency,high precision and low cost.