Structure Design,Preparation And Property Analysis Of Superhydrophobic Functional Fibers

In recent years,with the rapid development of electrospinning technology and inspired by the superhydrophobic phenomenon of animals and plants in nature,superhydrophobic materials have been widely studied in metal anticorrosion,membrane distillation,oil-water separation,fluid drag reduction,ice coating prevention,desert water collection and biocompatibility,and their potential value has attracted the attention of all sectors of society.However,the following problems exist in the preparation process of superhydrophobic materials at present:on the one hand,the preparation method is complex,and the practicability of superhydrophobic materials is not high,on the other hand,the preparation cost is too high,which is not suitable for mass production.Therefore,in order to realize the super hydrophobic fiber membrane with simple preparation method,strong practicability and high cost performance,the following research work has been carried out in this paper:(1)In order to prepare fiber membrane with better hydrophobicity and mechanical properties,polystyrene(PS)and polyacrylonitrile(PAN)were used as raw materials to prepare hydrophobic fiber membrane with side-by-side structure by electrospinning.Scanning electron microscope(SEM),contact angle measuring instrument,infrared spectroscopy(FTIR)and x-ray photoelectron spectroscopy(XPS)were used to characterize the surface morphology and structure of PS/PAN fiber membrane.The effects of content ratio and injection speed on fiber morphology and hydrophobicity were studied,and the oil absorption and hydrophobic stability of fiber membrane were tested.The results show that the fiber membrane has high hydrophobicity and oil absorption,its water contact angle(WCA)reaches 152°,and its maximum adsorption capacity for Tween 80 is 86.95g/g.(2)The superhydrophobic property is closely related to its surface roughness.Therefore,polymethyl methacrylate(PMMA)and polydimethylsiloxane(PDMS)are used as raw materials,and PMMA/PDMS fiber-microsphere structure is sprayed on PS/PAN fiber membrane to improve the hydrophobicity of fiber membrane.The morphology,hydrophobicity and structure of the fibers were characterized by SEM,WCA,FTIR and XPS.The relationship between spinning solution concentration,injection speed,hydrophobicity and micro-morphology was systematically studied.The fiber membrane with WCA up to 154.1°and excellent superhydrophobic stability was prepared.The membrane still has superhydrophobicity after being soaked in strong acid,strong alkali and high concentration salt solution for 8 hours,and still has hydrophobicity after 10 times of oil-water separation and ultrasonic cleaning for 30minutes,and its oil-water separation efficiency is as high as 97%,its oil flux reaches1065.07 L/(m²·h),and it has good oil-water separation performance.It is found that PS/PAN-PMMA/PDMS fiber membrane has good oil adsorption performance,and its adsorption capacity for silicone oil is the largest,which can reach 141.57g/g.(3)Nano-microsphere P25 titanium dioxide(Ti O₂)is selected as spraying material and the surface coating of microsphere structure is constructed to further improve the surface roughness because the preparation of fiber-microsphere structure is complicated and the ratio is difficult.A layer of PDMS/Ti O₂was sprayed on the surface of PS/PAN fiber membrane by electrostatic spraying technology and the WCA of PS/PAN-PDMS/Ti O₂fiber membrane was up to 156°.The oil absorption,oil-water separation performance,stability and self-cleaning performance of the composite fiber membrane were studied.It is found that the membrane not only has good oil absorption and oil-water separation performance but also has excellent repeated oil-water separation performance.After 10 repeated oil-water separation,the separation efficiency is still as high as 97%and the oil flux is still as high as 1818.97 L/(m²·h).The membrane still has superhydrophobic and self-cleaning properties after being soaked in strong acid,strong alkali and saturated Na Cl solution for 24 hours and still has good hydrophobicity under the condition of high temperature heating,which shows that the membrane has good corrosion resistance,thermal stability and self-cleaning properties.