Preparation Of Superhydrophobic Surface By Laser Technology And Research On Its Anti-icing Performance

Biomimetic superhydrophobic materials have a wide range of applications and great practical value,it has the functions of self-cleaning,oil and water separation,anti-corrosion,drag reduction and water collection,anti-icing,anti-fog,lifting ship buoyancy,electrical insulation flashover prevention,making microfluidic devices and so on.It can be used in many fields,such as house building,water treatment,metal protection,fluid drag reduction,aviation navigation,power electronic system,laboratory chip system,biological medicine and so on,It has always been the focus of people's research.Anti-icing is one of the main applications of superhydrophobic materials.Snow and ice accumulated on the surface are common natural phenomena,however,they sometimes cause serious inconvenience to people's daily life and production,and even threatening the safety of people's lives and property and bringing disaster.There are many kinds of deicing methods currently used,such as mechanical deicing,thermal deicing,chemical deicing,ultrasonic vibration deicing and electromagnetic pulse deicing etc.These passive ice-removing methods based on heat,electricity and manpower are not only time-consuming,power,energy consumption,low efficiency and high cost,and can not fundamentally solve this problem.Superhydrophobic surface can effectively prevent the occurrence of surface icing,is expected to solve this problem.This topic is devoted to the preparation of superhydrophobic surface and the basic research of its anti-icing properties.Two laser technologies were used to fabricate Polytetrafluoroethylene(PTFE)superhydrophobic surfaces by microprocessing.The main work is as follows:(1)The basic theory,preparation method and application in various fields of super hydrophobic are introduced,summarizing several factors that influence the performances of anti-icing,such as rough structure,roughness scale,mechanical strength of superhydrophobic surface,and the environment of low temperature and high humidity.According to the factors currently difficult to eliminate,the functional superhydrophobic surfaces with the characteristics of self-migration,easy-repairable and self-healing were introduced.Research status of the functional superhydrophobic surfaces were reviewed.(2)Femtosecond laser technology is widely used in biological,medical and micro-nano processing of various materials.The surfaces of PTFE were microprocessing by Ti sapphire femtosecond laser,and the micro grooved structure was obtained,and the superhydrophobic surfaces were prepared.The influence of different groove spacing on the surface hydrophobicity and anisotropy was studied.(3)PTFE surfaces were microprocessing by using carbon dioxide gas laser to prepare superhydrophobic surfaces.The effects of different micro channels spacing,different processing times and different processing powers on the surface morphology and wettability were studied,the contact angle was up to 168.36°.The anisotropy and self-cleaning performance were also investigated.(4)The self-made icing monitoring system was used to investigate the anti-icing performance of static and dynamic water droplets prepared by the two methods.The experimental results were also analyzed based on one-dimensional heat transfer theory and classical nucleation theory.