Preparation And Study Of Oganic-inorganic Nanocomposite Superhydrophobic Coating

Organic-inorganic nanocomposite coating consisting of organic polymers andinorganic nanoparticles has been attracting attention for the purpose of the creation ofhigh-performance or special features coatings. Superhydrophobic coatings are increasinglyattractive to the industry and academia due to their unique self-cleaning and anti-stickingproperties.In this paper, nanocomposite coatings were fabricated by incorporatinghydrophobic nanoparticles in low surface energy Organ silicon and fluoride polymers.Organ silicon system and fluoride system coatings are prepared.First of all, chemically absorbed onto the surface of modified silicon dioxide byγ-Glycidoxypropyltrimethoxysilane, Nano-silica/PTFE composite emulsions wereprepared by sol-gel method. The optimum experiment conditions were: mass ratio ofsilane coupling agent of5%, reacting temperature of50°C, pH of5.0, the weight ratio ofPTFE and SiO2was40%. We prepared aligned super-hydrophobicity with a watercontactangle as high as156°, possessing micro/nano-hierarchical such as the lotus leafsurface, the coating has higher hardness of about2H and the abscission rate of coating wasless than8%.Best modified conditions of colloidal silica were: the weight ratio ofPerfluorooctyltrimethoxysilane and SiO2was2%, reacting temperature of40°C, pH of5.0.When the weight ratio of PTFE and SiO2was35%, heat-treatment was120°C, providinglow surface energy and the necessary surface roughness,the water static angle and contactangle hysteresis of the resultant surface are160°and5°, respectively.CaCO3nanoparticles were modified from hydrophilic to hydrophobic with lowsurface energy oleic acid, filling nanoparticles into polymers polydimethylsiloxane,nano-sized CaCO3creates a dual scale of roughness, forming the superhydrophobiccoating. The modification temperature was40°C, the weight ratio of oleic acid and CaCO3was3%, reaction time was1h, the CaCO3and PDMS with a weight ratio of approximately7:3, tetraethyl orthosilicate as cross-linking agent, the crosslinking temperature was120°C,creating micro-and nano-structures dual scale of roughness, the superhydrophobic coatingwith a water contact angle of160°and sliding angle of5°.The coatings were characterized by Scanning electron microscope、Fourier transforminfrared spectrometry,contact angle apparatus and thermal synthetic analysis. The physicalstructure and the chemical composites of the surface, hydrophobic and mechanicalproperties are studied.