Preparation And Properties Of Dynamic Antifouling Materials Based On Hydroxyl-terminated Polydimethylsiloxane

Solid surface contamination has long been a problem,and modern technology based on surface interface technology provides some effective solutions to surface contamination.However,the existing anti-pollution technologies focus on high anti-pollution,that is,pollutants cannot adhere to the surface to achieve anti-pollution effect.In fact,the demand for anti-fouling technology in modern society is diversified.For example,for scenes such as building exterior wall glass,they need transparent coating and have high anti-fouling effect,which is also the problem to be solved by the current mainstream anti-fouling technology.For scenarios such as erasable writing,they need friction-resistant coatings and have both writeability and erasability,which not only involves the easy removal of surface attachments,but also involves their adhesion.Up to now,how to prepare a antifouling surface with strong wettability and high antifouling property is still an obvious technical challenge.Polysiloxane is a common material for the preparation of antifouling coatings.It has the advantages of extremely low surface energy,excellent physiological inertia,high biocompatibility,non-toxic and tasteless,and has broad application prospects in the fields of antifouling coatings,gasliquid sealants,medical and health devices.In this paper,two kinds of antifouling coatings with different functions were prepared by controlling the polymerization of various siloxane components under catalyst conditions,and the relationship between the adhesion and antifouling properties of the coatings was systematically studied.The main content of this paper is divided into the following three aspects:(1)Transparent reactants were prepared by regulating the hydrolysis condensation reaction of methyl trimethoxysilane(MTMS)and ethyl orthosilicate(TEOS)under the condition of catalyst,and the transparent,durable and erasable coatings were finally prepared by spincoating,drop coating and other processes.The effects of various components on the properties of antifouling coatings were studied by various methods.The structural of the antifouling coating was characterized by infrared spectroscopy(FT-IR),field emission scanning electron microscopy(SEM)and atomic force microscopy(AFM),and the mechanical and anti-adhesion properties of the coating were characterized by A-type Shore hardness tester,texture instrument and paint film bending tester.Experimental results showed that the best curing effect was obtained when the catalyst and GPTMS content were 4% and 5% respectively.Moreover,the coating had excellent adhesion resistance and peel strength was only 8 N/m.(2)The antifouling mechanism of the highly durable writable and erasable coating was further investigated and the antifouling effect of the coating was tested.Experimental results showed that the advance and retreat angles of the coating surface decrease continuously with the increase of UV treatment time,and a critical retreat angle of about 65 °-70° appears with the increase of UV treatment time to 10 min.When the receding angle of the coating was higher than 70°,the coating tended to be difficult to write and erasable as the increase of the receding angle.When the receding angle of the coating was less than 65°,the coating tended to be writable and difficult to erase as the receding angle decreases.In addition,the antifouling properties,friction resistance and light transmittance of the coatings were studied systematically.The results showed that the coating had a good antifouling effect even after 9 weeks of time the coating still had a good writable and erasable effect,and after 2000 times of friction experiments,the surface of the coating had no obvious signs of destruction.In addition,the visible light transmittance of the coating can reach up to 91.4 %.(3)Based on the antifouling mechanism of the writable and erasable coating,a coating with high stain resistance was prepared.The results show that when the content of TEOS is20%,the coating has high transparency and excellent anti-graffiti,anti-fingerprint,hydrophobic and hydrophobic properties.Immersion of the coating in acid,alkali and salt solution for more than 5 days can still maintain good corrosion resistance,in addition,the coating also has good adhesion.