Preparation And Performance Study Of An Instantaneously Cured Wear-resistant Superhydrophobic Materia

Superhydrophobicity is a special wetting phenomenon presented on the surface of many natural materials.Superhydrophobic coatings possess strong functions and utility in surface self-cleaning,anti-icing,fluid dampening and oil-water separation due to their extremely high water repellency,which result in broad application prospects in the fields like pipeline transportation,household cleaning,clothing finishing and engineering waterproofing.However,the availiable superhydrophobic materials harbor many deficiencies.First,a typical feature of superhydrophobic technology is the construction of micro-and nanostructures,while the poor stability of such microstructures remains the biggest technical challenge for the development of superhydrophobic coatings.Second,fluorinated compounds,due to its low surface energy,are used in large quantities to prepare superhydrophobic surfaces,but fluoride is expensive,difficult to degrade and potentially harmful both to humans and the environment,which raises not only the cost of the technology but the environmental impact.Third,for a effective and durable superhydrophobic coatings,current techniques are forced to full of complexity with precision equipment and high processing conditions,which make sgainst to the widespread use of superhydrophobic technologies.To address the above problems,this thesis is based on the strategy of"coating+bonding",depending on the effective intergration of highly hydrophobic coating components and high-strength bonding components,so that the coating system can simultaneously retain ultra-high hydrophobicity and strong adhesion and physicochemical stability successfully.Meanwhile,on account of the high reactivity of the system,a superhydrophobic coating that can be cured fleetly and wear-resistant is ultimately fabricated.In this paper,hydrophobic surfaces were firstly prepared by co-polymerization of polydimethylsiloxane（PDMS）and small molecule ethyl orthosilicate（TEOS）,followed by the construction of micro and nano rough structures using hydrophilic silica,and finally the coating system was made highly structurally stable by using POSS as a highly reactive component to enhance structural stability and adhesion.The process involves neither fluoride modification of the surface,expensive reagents,nor precision equipment and rigorous experiment conditions,on the contrary,the process is simple and controllable,and the prepared wear-resistant superhydrophobic coatings can be quickly cured for different substrates,which owns promissing application prospects.The main research of this paper is as follows:（1）A fast-curable superhydrophobic coating was prepared using the acid-catalyzed co-hydrolytic condensation reaction between PDMS and TEOS,combined with hydrophilic silica as the structuring component.The effects of raw material ratio,Si O₂ size and dosage,and solvent on the hydrophobic properties and coating morphology were systematically investigated.The results showed that when the composition ratio was PDMS:TEOS:Si O₂=5.0:1.0:0.1 and the Si O₂ particle size was 15 nm,the advancing/receding angle of water droplets on the coating surface reached 172.4°/171.6°,and the hysteresis angle was within 1°.The thermal properties and chemical stability of the coating are good and can withstand more severe heat treatment and a certain degree of exposure to acid,alkali and salt solutions.（2）POSS was used as a strong bonding component and added to the above PDMS@Si O₂system to obtain a wear-resistant superhydrophobic coating that could be cured rapidly.The effect of the mass ratio of Si O₂:POSS on the hydrophobicity of the coating and the adhesion of the coating was investigated.The results show that the superhydrophobicity and adhesion of the coating are well maintained when Si O₂:POSS=1:3.A large number of pores and irregular layered microstructures existed on the coating surface.The coating was subjected to friction,bending,scratching,running water and heavy impact and tested its surface properties,and the results showed that the coating has good damage resistance.Applying the coating on the fabric,the modified superhydrophobic fabric can be treated with high separation efficiency and high flow rate for oil-water separation,and the modified fabric has good damage resistance to friction and washing tests.（3）A water-based polysiloxane water-repellent emulsion was further studied and prepared to achieve an environmentally friendly turn in the fabric treatment process.The optimal formulation and process of the system were determined by examining the effects of raw material ratio and the amount of emulsifier on the hydrophobicity of the modified fabric surface.The modified fabrics exhibited good self-cleaning properties,oil-water separation properties,mechanical stability and chemical stability.