The Preparation And Characterization Of ABS Ultrafiltration Membranes With Micro-monocrytalline Si As Pore Former Etched By KOH Solutions

At present,ultrafiltration membranes were widely used in many fields such as water industry,chemical industry,pharmaceutical industry and food industry and so on.Universal thermoplastic polymers such as acrylonitrile-butadiene-styrene copolymer?ABS?had excellent impact strength,good dimensional stability,abrasion resistance,chemical resistance,and mechanical properties,which was an excellent ultrafiltration membrane material with the comprehensive performance of conventional organic membrane material.This article based ABS as ultrafiltration membrane material,monocrystalline silicon Si as pore former,and KOH solution as etchant.Meanwhile,phase inversion and chemical etching techniques were combined to prepare ultrafiltration membrane.The influence of the etching solution on the structure of the ABS material was eliminated by the infrared spectrum.And using EDS elemental analysis to detect that the KOH solution could completely remove the silicon Si from the ABS ultrafiltration membrane.The size of the pores was much smaller than monocrystalline silicon Si on account of the anisotropic shrinkage observed by SEM scanning electron microscopy.In addition,in this experiment,there are two ways to prepare ultrafiltration membrane pores:monocrystalline silicon Si itself and the pores of less than200nm prepared by H₂ released by the reaction between KOH solution and monocrystalline silicon Si.The membrane pores prepared by monocrystalline silicon Si itself greatly increased the pure water flux and porosity of the ABS ultrafiltration membrane,and the membrane pores prepared by H₂ increased the retention performance of the ultrafiltration membrane.The ultrafiltration membranes with 25wt%ABS and 50?m monocrystalline Si had a good comprehensive performance:the pure water flux 40.96⁸22.76 L·m^-2·h^-1,and the porosity 44%⁵9.4.%,and the rejection rate to PEG20000 was 71.95%to 91.1%.The nonsolvent-insoluble monocrystalline silicon Si as pore former in this experiment had great potential applications in the preparation of ultrafiltration membranes,and at the same time provided new options and value references for the types of ultrafiltration membrane additives.Silicon anisotropic etching technology is widely used in many fields such as microelectronics technology and sensors.In the alkaline etching process of monocrystalline silicon,the corrosion rate of the alkaline etching solution to monocrystalline silicon was often too fast,resulting in inconsistent roughness of the surface of the silicon wafer.However,alcohols,such as isopropanol,had the function of slowing down the reaction rate and the rate of bubble formation.However,the retention rate of the ABS ultrafiltration membrane prepared in this paper was determined by H₂.Therefore,based on the previous experiments,the use of alcohol in the microelectronics technology was introduced to into the membrane process in order to explore the effects of alcohols on the rejection rate of ABS ultrafiltration membranes,and confirm the best process conditions,aiming at increasing the rejection rate of ABS ultrafiltration membranes.At the same time,the effects of the type and concentration of alcohols,type and concentration of lye on the rejection of ABS ultrafiltration membrane were studied.The results showed that the mixed etchants with 5wt%-0.5 mol/L KOH-isopropanol had a significant enhancement in rejection of ABS ultrafiltration membranes.Compared with 5wt%KOH single etchant,the rejection rate of ABS ultrafiltration membranes increased from 82.29%to 94.5%,greatly improving the retention of ultrafiltration membranes.