| The quality of insulators used in power transmission lines is directly related to the reliability and stability of the power system.At present,the flashover caused by the icing on the insulator surface still poses a serious threat to the safety of the transmission line,and the power grid accidents caused by icing can still cause serious economic losses and broad social impacts.Therefore,carrying out research on new anti-icing technologies for power transmission line is of great significance in both scientific and engineering fields.In this dissertation,a method for preparing organic polymer coatings with superhydrophobicity based on aerosol-assisted chemical vapor deposition(AACVD)was studied.The three-layered wear-resistant EP/PDMS coatings were prepared by the dynamic temperature control method(EP is an abbreviation for Epoxy resin;PDMS is an abbreviation for Polydimethylsiloxane).The wettability,abrasion resistance and electrical properties of EP/PDMS coatings were studied.The properties of the EP/PDMS coating applied for different conditions were also systematically investigated.The anti-icing performance and the microscopic dynamic condensation of water vapor on the coating surface were observed,and the mechanism was analyzed.The main innovations achieved in this paper are:(1)A method based on aerosol-assisted chemical vapor deposition for the preparation of organic polymer wear-resistant superhydrophobic coatings was proposed.After comprehensive consideration of the factors related to the preparation of the superhydrophobic coating including the process,materials and coating properties and so on,a multi-layer periodic wear-resistant EP/PDMS superhydrophobic coating composed of epoxy resin with high adhesion used as a precursor was obtained by adjusting the micro/nano structure of the coating via the dynamic temperature control method based on aerosol assisted chemical vapor deposition technology.The EP/PDMS coating was found to be extremely superhydrophobic by the bounce performance of water droplets on the coating surface.The superhydrophobic EP/PDMS coatings were also found to have excellent electrical properties in terms of dielectric properties,surface resistivity and flashover performance.The preparation process can be not only applied to a variety of different substrates but also a reference for preparing other organic polymer coatings based on aerosol-assisted chemical vapor deposition.(2)The superhydrophobic EP/PDMS coatings can be long-term well applied under a variety of conditions.It was found that the superhydrophobic EP/PDMS coatings have excellent resistance to water droplets and sand powder impact,resistance to UV radiation and corrosion resistance to acid and alkali solutions,while also being able to maintain the effective self-cleaning for various powder and liquid contamination.In addition,the EP/PDMS coating was found to possess durable anti-icing property by conducting multi-cycle icing and frosting tests as well as prolonged icing and freezing tests on the coating.It is mainly attributed to the robust micro/nano structure of EP coating,the combination of PDMS with EP coating and the stable properties of the two materials themselves.(3)The effectiveness of anti-icing property of the superhydrophobic EP/PDMS coating was verified.The anti-icing mechanism was preliminary explored by considering the heat transfer and water droplet bouncing on the surface of superhydrophobic EP/PDMS coatings.The limitations of anti-icing performance of superhydrophobic EP/PDMS coatings surface were analyzed from the surface defects and the reduced superhydrophobicity of the coating at low temperature.In addition,the ambient temperature and humidity was precisely controlled based on the environmental scanning electron microscope,and the microscopic dynamic condensation of water vapor on the superhydrophobic coating was observed.It was found that under the saturated water vapor environment,the superhydrophobic EP/PDMS coating can significantly inhibit the condensation of water vapor at a higher temperature(1°C).This phenomenon is explained that the surface roughness and low surface energy of the superhydrophobic EP/PDMS coating lead to the greater Gibbs free energy while the water droplets form on the EP/PDMS coating. |
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