Preparation Of Superhydrophobic Fiber With Controllable Micro/nano Structure Via Centrifugal Spinning

Many plants and animals in nature have hydrophobicity,such as lotus leaf,water strider legs,butterfly wings and bird wings,etc.Superhydrophobic material has a wide range of applications in daily necessities,public buildings,as well as national defense aviation and so on for its special features of waterproof,anti-fouling and the ability of alleviating fluid stranded,etc.Nanofiber has lots of advantages,including small fiber diameter,large specific surface area,high porosity,etc.It as an important raw material is widely used in tissue engineering scaffolds,drug delivery,filter media,artificial blood vessels,biochips,nano-sensors and other fields.Currently,the combination of nanofibers and preparation of superhydrophobic interface materials is a hotspot.And there are many methods of preparation nanofibers,such as template synthesis,phase separation,self-assembly,electrospinning and centrifugal spinning,etc.The yield of electrospinning is low,which restricts its large-scale application in commercial;centrifugal spinning is a promising method with simple mechanical structure and high yield,without high pressure and pollution in industry;while other methods are complex and can only be used to prepare limited types of polymer nanofibers.In this paper,superhydrophobic polystyrene?PS?fibers were prepared by centrifugal spinning technique.The effects of spinning parameters on fibers structure and different methods on constructing super-hydrophobic surface were studied;meanwhile,the mechanical strength of polystyrene fibers was also improved.Morphology and hydrophobicity of PS fibers prepared by centrifugal spinning were characterized by field emission scanning electron microscopy,infrared spectroscopy,X-ray diffraction,X-ray photoelectron spectroscopy and contact angle measurements.The experimental results show that centrifugal spinning technology is an alternative approach to fabricate superhydrophobic PS micro/nano fibers with controllable structure,which will have important academic and application significance in relieving the environmental pollution and energy consumption caused by the surface cleaning.The main contents are as follows:The morphology of the PS fibers can be manipulated by selectively controlling spinning parameters.The results show that the spinning parameters have regular influence on the structure of PS fibers.The nanoscaled PS fibers with porous structure and certain hydrophobicity were prepared under solution concentration of 16 wt.%,rotational speed 8000 rpm,nozzle diameter 0.4mm and nozzle-collector distance 12 cm.A one-step method was used to roughen PS surface by adding nano SiO₂ particles to spinning solution.The superhydrophobic PS fibers with double biomimetic structure?nano-protrusions of lotus leaf and grooves of silver leaf?were successfully prepared.The results show that the surface roughness can be increased by introducing SiO₂ onto PS fibers surface to further improve the hydrophobicity.The PS fibers have a maximum contact angle of 151° when SiO₂ content is 3wt.%.Applied a two-step method,firstly,the fibers surface was roughened by dipping in SiO₂ sol;then the fibers was dipped in D4^Vi monomer and followed plasma was used to induce polymerization of D4^Vi,which formed low surface energy film and deposited on fibers surface.And the superhydrophobic PS fibers with both nano-protrusions and low surface energy film were successfully prepared.The results show that the modified PS fibers have a maximum contact angle of 158° under a load pressure of 20 Pa,radio frequency power 80 W and time 2 min.PAN/PS fibers were successfully prepared by blending the polyacrylonitrile?PAN?with PS to improve the strength of PS fibers.The results show that the strength of blended fibers are improved 3 times compared with PS fibers when PAN/PS = 3/1.