The Preparation And Properties Of Biomimetic Hydrophobic And Oleophilic Surfaces

Recently,Through millions of years of natural evolution,plants and animals have adapted perfectly to nature.Since ancient times,nature has been the source of man's technological ideas,engineering principles and great inventions.After a long period of evolution,all kinds of creatures can adapt to changes in the environment,so as to survive and develop.Wettability refers to the ability of a liquid to wet the surface of the solid phase,that is,the ability or tendency of a liquid to spread on the surface.The lotus leaf is constantly considered as the symbol of purification as the ancient Chinese poetry “come out of mud unsoiled” goes.The superhydrophobicity was resulted from micro and nanoscale hierarchical structures on the leaf.Microscale papillae and the epicuticular wax provided a special model.Pitcher plants capture insects,and the super slippery nature of their bottle caps is due to the irregular arrangement of tiny grooves that lock up the waxy material.The Namibian desert beetle can survive in harsh conditions with a knobby shell that helps collect droplets of fog from the air.These are closely related to the wettability of the material surface.Over the past ten years,there have been numerous researches on the superhydrophobic surface,but the complex process,poor stability and heavy pollution have been urgently solved.Given this,I focus on the hydrophobic and oleophilic surfaces which are easy to operate,stable,durable and environmentally friendly.In daily life,scaling widely exists in pipeline transportation,textile and chemical industry,power plant,metal material processing and biological engineering industries.As for the aircraft flying at high altitude,due to the low temperature,the ice covering the fuselage not only increases the load,but also can cause catastrophic damage.How to reduce the ice accretion has become a global concern.The leakage of oil transport by sea would also be devastating to the ecology.This kind of hydrophobic and oleophilic surface has a broad application prospect in the fields of oil-water separation,anti-fouling,ice-phobic,drag reduction and fog harvesting.In view of this,I seek for a simple and reliable method for the fabrications of the biomimetic hydrophobic and oleophilic surface.Then various characterization and performance studies are carried out to develop a series of functional surfaces with good effect and stability.The overall research work can be divided into three parts:(1)Hydrophobic polyurethane sponge was prepared by zirconia nanoparticles ethanol dispersing solution.Then the hydrophobic sponge was modified by stearic acid to obtain the features of superhydrophobicity and superoleophilicity.The surface morphology and chemical composition of the treated sponge were analyzed.After dozens of adsorption experiments,the sponge can still help to absorb oil,which is of great benefit to the separation of oil-water emulsion.(2)Through a simple binary silanization method,a self-cleaning cotton fabric was prepared,which can be used for oil-water separation.By durability tests,the cotton fabric was still hydrophobic after dozens of jet impingement experiments,which showed good mechanical strength.The cotton fabric was then immersed in different acid and alkali solutions for a week.The maintained superhydrophobicity feature exhibited excellent chemical durability of the cotton fabric.(3)Utilizing the good adsorption function of MOFs,researchers created a special structure of hydrophilic and hydrophobic phase based on MOFs and copper hydroxide nanowires.It is helpful to solve the problem of water shortage,which is of great significance to the production and life of human beings.