Hydrophilic Modification And Antifouling Properties Of IPP/GO Hollow Fiber Membrane

In this paper,an iPP/GO blend membrane was prepared by thermal phase separation method using grapheme oxide(GO)as modifier with high tensile strength,high water flux and good anti-pollution performanceWe mainly investigated the influence of spinneret temperature,air gap distance,water bath temperature on membrane structure,tensile strength,compaction,pore size distribution,porosity and water flux.The results show that the polypropylene hollow fiber membrane exhibits a good bi-continuous structure,and the porosity is basically unchanged.As the spinneret temperature increases,the tensile strength,compacting and water flux increase firstly and then decrease.The tensile strength decreases,and the average pore diameter,water flux and compactness are on the rise with the increase of air gap distance and water bath temperature.In the optimized operating condition,SEM,FTIR,XPS,contact angle and water flux were used in the detailed characterization with GO addition changing.The study found that with the addition of GO,the contact angle of polypropylene film decreased from 125°to 52.33°and decreased by 58.14%.The FTIR test shows that hydrophilic hydroxyl group and carboxyl group are present on the modified membrane surface.The test results of XPS show that oxygen elements appeared in the modified polypropylene membrane and exhibits a rising trend,which further confirms that GO successfully mixes into polypropylene membrane.At the same time,the performance of the polypropylene blend membrane was increased and then decreased.When the GO content was 0.3%,the membrane performance was the best,the porosity was 67.67%,and the water flux reaches 1345 L/(m~2.h),with an average pore diameter of 0.4722μm.The antifouling properties were analyzed by the filtration of bovine serum protein solution,milk powder solution and emulsified oil solution.The results show that the attenuation rate of GO modified film flux is less than that of pure polypropylene film,and the attenuation rate of the blend film is the minimum when the amount of the GO addition is 0.3%,and the water flux recovery rate is the highest after cleaning.In the process of emulsified oil filtration,the retention rate of modified film decreased slightly to 89.2%.The stable flux of pure polypropylene film was 22.44 L/(m~2.h),while the 0.3%blend film was 301.53 L/(m~2.h).Different cleaning methods were adopted to cleanpolluted membrane,and SDS achieved the best cleaning effect.Unmodified membrane flux recovery rate was just 67.07%,and 0.3%GO addition blend membrane is 93.99%.Moreover,it shows that raising the temperature of the cleaning solution can improve the flux recovery of polypropylene membrane.