Superhydrophobic Modification Of Heat-shrinkable Polyvinyl Chloride And Its Application In Anti-icing Of Wind Turbine Blades

Wind power generation is an environmentally friendly way to produce electricity,and it can significantly alleviate the pressure of energy shortages caused by burning non-renewable resources such as oil,coal,and natural gas.China is good at utilizing wind energy to generate electricity,but wind turbine blades that are prone to freeze in winter will reduce the efficiency of the generator,and seriously restrict the development of wind power industry in China.Nowadays,there are many deicing methods for wind turbine blades,such as mechanical deicing,thermal deicing,and coating deicing,but all have certain drawbacks.Herein,the anti-icing and anti-UV heat-shrinkable film was prepared to coat blade for alleviating or eliminating icing on the surface of blade.The details are as follows:（1）The common heat-shrinkable films were investigated and their properties were tested.Finally,heat-shrinkable PVC（HSPVC）films were selected as modified substrates;（2）Surface etching of HSPVC film.HSPVC films were pretreated respectively by argon and carbon tetrafluoride（CF₄）plasma cleaning to etch the surface of HSPVC,generate active sites,change its surface energy and improve the bonding fastness of the deposited PTFE nanoparticles to the substrate.Compared with the sample without plasma cleaning,the pretreatment of Ar and CF₄ plasma can etch the surface of the substrate to increase the roughness of the film.Compared with the samples without plasma cleaning,the surface of the samples pretreated by Ar or CF₄ plasma was etched,and the roughness of the films was increased.After Ar plasma cleaning,hydrophilic groups were introduced on the surface of the film,resulting in a decrease in contact angle from 76.7°to 22.5°and an increase in surface energy to 51.8 mN/m.The F element introduced by CF₄ plasma pretreatment re-bonded with the active point,which causes the surface of the PVC heat shrinkable film to be fluorinated,the contact angle is increased to 93.4°,and the surface energy is reduced to 32.7 mN/m.（3）Superhydrophobic modification of HSPVC film surface.The polytetrafluoroethylene（PTFE）/heat-shrinkable polyvinyl chloride（HSPVC）composite film was prepared by depositing the PTFE coating on the surface of HSPVC film via vacuum thermal evaporation.After CF₄ plasma pretreatment,PTFE coating with a thickness of about 4μm was deposited on the surface of HSPVC,obtaining a superhydrophobic surface with an apparent water contact angle of 150°and contact angle hysteresis of 4°.The results demonstrated that the breaking strength of the PTFE/HSPVC composite film using CF₄ plasma pretreatment decreased from 58.70%of the original HSPVC film to 3.47%after exposing for 5 min under 1000 W ultraviolet lamp,suggesting its excellent anti-ultraviolet property.Furthermore,compared with the pristine films,the PTFE/HSPVC composite films exhibited better adhesive strength and super anti-icing property even after 10^thh cycle icing-deicing process.（4）Installation process of PTFE/HSPVC composite film on wind turbine blade.Solidworks software was used to establish the model of wind turbine blade and installation of PTFE/HSPVC composite film.By analyzing the modeling process,a new installation process is proposed,and a heating device is designed for this process.Through this installation process,PTFE/HSPVC composite film with good adhesive strength,anti-ultraviolet,and anti-icing properties can be packaged on the blades of wind turbines,which makes the research have important ecological value and economic value.