Electrospinning Preparation And Modification Of Polymer Composite Adsorption Membranes And Properties

With the rapid development of industrial technology,many environmental problems have also emerged,such as:air pollution and soil pollution.Among them,water pollution caused by organic pollutants and heavy metal ions has a serious impact on human production and life,and threatens human health.At present,the mainstream methods to solve the problem of water pollution are adsorption and photocatalysis.Adsorption is the use of adsorbents to separate pollutants from water,the photocatalytic technology is the use of the redox ability of photocatalysts to destroy the molecular structure of organic pollutants and reduce high-valent heavy metal ions,to achieve the purpose of treating pollutants in water.Therefore,it is the focus of current research that preparation of environmentally friendly high-efficiency adsorption materials and photocatalytic materials.In this article,we mainly use high-voltage electrospinning technology and solvothermal method to prepare highly efficient photocatalytic and adsorption materials for the removal of organic pollution and heavy metal ions in water pollution.The specific contents are as follows:（1）First,the TiO₂ particles were synthesized by solvothermal method,then the PAN/TiO₂ fiber membranes were prepared by electrospinning technology,and subsequent in-situ oxidative polymerization of aniline（ANI）on PAN/TiO₂ fiber membranes,and finally PAN/TiO₂/PANI hybrid fiber membrane were successfully prepared.Through the traditional photocatalytic experiment,it was found that the optimal addition amounts of TiO₂,ANI are 0.1g and 40?L.Importantly,the hybrid membranes have excellent adsorption properties for anionic dyes and can effectively adsorb Congo red in water.The investigation found that the adsorption behavior conforms to the Langmuir model,indicating that it is chemical related adsorption.In addition,the adsorbed hybrid membrane can be degraded and regenerated by photocatalysis under visible light irradiation.After 4 times photocatalytic regeneration experiments,the regeneration efficiency and removal rate can still be maintained at around 60%and 50%,respectively.This adsorption and regeneration performance can also be extended to heavy metals Cr（VI）,through the photocatalytic procedure to reduce and desorb Cr（VI）adsorbed on the hybrid membrane,so as to achieve effective regeneration.（2）The PS fiber membranes are synthesized by electrospinning technology,and without destroying the surface structure of membranes,then use low temperature NH₃plasma to modify the amino group on the surface to improve the hydrophilicity of materials.It was explored that the effect of applied voltage,ammonia flow rate and reaction time on the size of contact angle by static contact angle measurement.Among them,under the conditions of applied voltage of 50 V,ammonia gas flow rate of 70sccm and reaction time of 30 min,the contact angle of modified amino PS fiber membrane is 16.58°.Compared with the hydrophobic unmodified PS fiber membrane,it was showed that strong hydrophilic characteristics.Finally,it was found that the adsorption behavior of PS fiber membranes modified by amino groups to Congo red and fluoride ions.（3）The micro-nano structure ZnFe₂O₄ hollow spheres are synthesized by hydrothermal method,it is a large microsphere of 2μm formed by interconnecting nanospheres.The nanometer ZnFe₂O₄ hollow sphere has about 100-400nm in diameter and³nm in thickness.Compared with nano-scale ZnFe₂O₄ hollow spheres,the micro-nano structure has a larger specific surface area,about 52.037 m²/g.Then it was discussed that the effects of hydrothermal reaction time and temperature to the morphology,and improve the photocatalytic performance of ZnFe₂O₄ hollow spheres by addition of graphene oxide slurry（GO）.The combination of GO and ZnFe₂O₄hollow spheres uses GO as the core,and the nano-scale ZnFe₂O₄ hollow spheres as the external structure are connected to form a microstructure.Finally,through photocatalysis experiments,it was proved that when the amount of GO added was 1mL,the photocatalytic effect was the best,and the removal rates of Congo red and methylene blue reached 85%and 96%.