Preparation And Application Of Straw Carbon Based Superhydrophobic Coating

The phenomenon of not being wetted by water and aqueous solution widely exists in plants,animals and insects in nature.This phenomenon is later called superhydrophobic phenomenon.Through in-depth research,it is found that the surface with superhydrophobic phenomenon has excellent properties such as water repellency,self-cleaning and corrosion protection.These properties have great application potential in industry,agriculture and daily life.With the rise of bionics and the continuous development of the research on artificial superhydrophobic surfaces,a large number of preparation technologies have been developed.Raw materials from different sources can be used to prepare superhydrophobic surfaces,and solid surfaces with different properties and structures can be constructed with superhydrophobic properties.However,in the process of the continuous development of superhydrophobic materials,many problems have also been exposed,such as high preparation cost,complex preparation process and the use of fluorine-containing and toxic chemicals,which make superhydrophobic materials face great challenges in practical application.In this study,based on the purpose of low cost and environment-friendly,we proposed a simple drip coating strategy.Using corn straw from a wide range of sources and environmental protection as raw materials,a superhydrophobic coating with self-cleaning performance and corrosion protection performance was prepared based on a fluorine-free and non-toxic system.The main research contents are as follows:(1)In this part,we present a facile dip-coating strategy to prepare superhydrophobic coatings with self-cleaning properties based on a non-fluorine and non-toxic system by using eco-friendly corn straw as raw material.During this process,aromatic carbon particles with rough hierarchical structures were prepared firstly via a simple fast pyrolysis process,followed by modification with polydimethylsiloxane(PDMS)in absolute ethanol solvent to decrease the surface free energy.Research shows these natural straw-derived carbons display a microstructure of several protrusions which is similar to the lotus leave's and the resulted coatings exhibit an outstanding superhydrophobic property with a static water contact angle(WCA)of 151.67�1.36and sliding angle(SA)of 8 degrees.In addition,the as-prepared coatings possessed excellent self-cleaning performance:no contaminations were observed on the surfaces after examining with sludge,calcimine,water,and common liquids such as tea,milk,soybean milk as well as ink,which have a broad range of potential ap-plication in the field of antifouling,waterproofing,and anticorrosive.(2)Corn straw porous carbon polyaniline(PANI)composite was prepared by in-situ oxidative polymerization,and then a superhydrophobic coating with corrosion protection was prepared on the surface of metal aluminum by drop coating.Based on the study of self-cleaning superhydrophobic surface,firstly,carbon dioxide(CO₂)released by sodium bicarbonate(Na HCO₃)at high temperature is used to give carbon porous structure while carbonizing corn straw.Then PANI was loaded on the surface of porous carbon by in-situ oxidation polymerization.Finally,superhydrophobic coating was prepared by drop coating.Electrochemical test results show that the composites of porous carbon(BC)and polyaniline(BC@PANI)The anti-corrosion performance of is obviously better than that of pure BC and PANI coatings,and can be used for metal corrosion protection.