Preparation Of Super-hydrophobic Fiber Membrane By Electrospining And Its Application In Oil-Water Separation

The oil pollution caused by industrial accidents,oil transportation and the discharge of oily wastewater from industries such as catering and textiles have caused catastrophic damage to humans and marine.Therefore,the separation of oil from oily wastewater is an important research direction.However,the traditional oil-water separation method has some shortcomings,such as complex process,high cost,low separation efficiency and easy to cause secondary pollution.Therefore,it is urgent to develop an environmentally friendly,cost-effective and large-scale production technology to reduce the damage caused by oil pollution to the environment.The fiber membrane prepared by electrospinning has high permeability and separation efficiency,and the process is simple and the cost is low.Therefore,the superwetting separation membrane prepared by electrospinning has attracted more attention in the field of oil-water separation.At the same time,improving the stability and reusability of the superwetting separation materials is also the focus of current scientific research.This paper mainly includes the following aspects:?1?The superhydrophobic PS fiber membrane was prepared by directly depositing PS fibers on a stainless steel mesh by electrospinning using hydrophobic polymer polystyrene?PS?as a substrate.Three different kinds of insoluble oil-water mixtures were separated.The results show that the separation efficiency is higher than 98%.,the maximum flux is 618±5 L m^-22 h^-1.Several factors affecting separation efficiency and oil flux?mesh number of stainless steel,fiber deposition time?were studied.The results show the mesh number of stainless steel and fiber deposition time have little effect on the separation efficiency but the oil flux decreases with the increase of mesh number of stainless steel and fiber deposition time.At the same time,the pH stability and reusability of PS fiber membrane were studied.The results show that the superhydrophobic PS fiber membrane had good pH stability,but it could not be recycled because it was easily dissolved in the oil phase containing halogenated hydrocarbonsand aromatic hydrocarbons.?2?In order to prepare the fiber membrane which can exist stably in the oil phase containing halogenated hydrocarbon and aromatic hydrocarbon.Try to use cellulose acetate as the base material.Firstly,several factors affecting the morphology and diameter of acetate fibers were studied.The optimal spinning solution concentration is 12 wt%-14wt%,the spinning voltage is 12-14 kV.And the fiber morphology is the best.when V_{acetone/N,N dimethylacetamide?DMAC?}=3:2 is used as the solvent,the propulsion rate is 0.5-0.8 mm/min,and the tip-to-collector distance is 20cm.Under optimal spinning conditions cellulose acetate was modified by differentsilanecouplingagents(?C₂H₅O?₃Si?CH₂?₂?CF₂?₅CF₃;?CH₃O?₃Si?CH₂?₁₇CH₃;?CH₃O?₃Si?CH₂?₇CH₃;?C₂H₅O?₃Si?CH₂?₃NH₂;?C₂H₅O?₃SiCH₃).And it was proved that the silane coupling agent successfully adhered to the acetate fiber membrane surface by the surface morphology,XPS and EDX before and after modification of fluorosilane.In contrast,different silanes were used to modify the surface of the filter paper.It was found that the hydrophobicity of the modified acetate film and the filter paper surface increased with the increase of the carbon chain length of the silane coupling agent.Different kinds of insoluble oil-water mixtures?cyclohexane,bromobenzene,petroleum ether?were separated by cellulose acetate fiber membrane modified by different silane coupling agents.The results show for straight chain modified alkanes,the longer the carbon chain,the higher the separation efficiency.And the type of oil has no obvious effect on the separation efficiency.At the same time,the adsorption capacity of the modified celluloae acetate film was 10 times that of the modified silane filter paper.Taking fluorosilane modified acetate fiber membrane as an example,the pH stability,wear resistance and recycling of the modified fiber membrane were investigated.The results show that The silane-modified cellulose acetate membrane not only has good pH stability,but also has a contact angle of 141.8±0.5°after 500 times of friction.After 10 cycles of oil-water separation,the separation efficiency can still be maintained at 98%.Cellulose acetate is biodegradable and environmentally friendly,Therefore,the silane modified cellulose acetate has broad application prospects.