Study On Preparation And Properties Of Bioinspired Durable Super-hydrophobic Materials

Superhydrophobic functional materials have demonstrated broad application prospects in self-cleaning,antifouling,anticorrosion,antifogging,anti-icing,antibacterial,oil-water separation,etc.At present,a variety of techniques have been successfully developed to construct the super-hydrophobic surface.However,the inherent disadvantages of the super-hydrophobic materials,such as fragile mico-nano structure,vulnerable to wear,scratch and corrosion,severely limit their applications in industrial production and daily life.Hence,it is of great significance to endow the super-hydrophobic materials with high durability.Herein,inspired by dolphin skin,lotus leaf surface and honeycomb structure,a durable superhydrophobic material consisting of flexible polydimethylsiloxane?PDMS?and SiO₂ nanoparticles was prepared.A series of tests were carried out to verify the durability of the material,and explore the related mechanism.In addition,the oil-water separation properties of this material were also studied.Firstly,SiO₂ nanoparticles were chemically modified by dodecyl trimethoxysilane?DTMS?to render them hydrophobicity.The SiO₂ nanoparticles and PDMS were combined to form a PDMS/SiO₂ super-hydrophobic coating,and its microstructure and hydrophobic properties were studied in detail.The influence of the contents and particle size of SiO₂ nanoparticles on the super-hydrophobicity of samples were investigated to confirm the optimal preparation conditions.Abrasion tests were carried out on the samples to evaluate the wear resistance of the coating.The results show that the sample can bear short distance sandpaper abrasion at the pressure of 5.6 kPa,but fail to maintain its super-hydrophobic performance when prolonging the abrasion distance and enhancing the pressure.In addition,PDMS porous elastomer was prepared through a template extraction of NaCl particles,from a composited PDMS matrix.The porous structure was obtained by the dissolution of NaCl particles in water,and the superhydrophobic property of the sample was obtained by the impregnation process.By changing the concentration of PDMS in solution,we optimized the preparation scheme of the material,and studied the elasticity of different samples by mechanical property test.The durability of the materials was investigated by the tests of mechanical stability,chemical stability,anderwater stability and thermal stability.The results showed that the sample still maintained excellent superhydrophobic performances even after being worn by 2000 cm at the pressure of 7.6 kPa,repeatedly scraped by knives,stripped by tape,exposed to corrosive liquid,soaked in deep water and placed in a high temperature environment.We also investigated the oil-water separation properties of the materials,and the results showed that the samples had high separation efficiency in repeated oil-water separation for n-hexane,toluene,dichloromethane,chloroform,gasoline and diesel.