Preparation And Technical Study Of Hollow Fiber Composite Membrane Support Layer

Mango is known as one of tropical fruit,it contains plenty of protein,vitamins,and rich nutrition,is popular with consumers.Mango grows mainly in the tropics,after picking,metabolism is exuberant,and is easy to rot,it led to a decline in production and escarpment susceptible to damage in transit,restricting the development of the mango industry.Therefore,mastering the effective storage of mango storage technology has become the key to the development of today's industry.Mango preservation methods are many,of which the development of more speed is the mango atmosphere storage method.Atmospheric storage by adjusting the temperature,humidity,gas composition and microbes to suppress the respiration of mango,slow down or delay the respiration rate of mango,delay the fruit ripening,to achieve mango storage preservation.Air conditioning equipment is the core of air conditioning storage,and membrane separation technology becomes the key to the operation of air conditioning equipment.Gas membrane separation mainly separate the different gases through the selective film of having different amounts of different gases.Hollow fiber membrane composite membrane has been widely used,so the performance of membrane separation technology has become the core.Therefore,the subject of this issue to carry out research,in order to achieve effective gas separation and to explore the preservation of mango.(1)In this experiment,PAN and PES hollow fiber membranes with different properties were prepared under different spinning conditions by dry-wet spinning phase inversion method.PES was selected as the membrane material.The structure of the membrane was controlled by changing the concentration of polyethylene solution,the concentration of DG,core flow rate,and coagulation bath temperature,prepared PES hollow fiber membranes with different N2?O2 and CO2 pure gas fluxes and CO2/N2?O2/N2 different separation coefficients.(2)PES was selected as the membrane material.Measured the viscosity on the different concentration of polymer solution,dragged the viscosity curve,analyzed the influence of polymer membrane flux to viscosity.The PES hollow fiber membrane was prepared by post-treatment,dried and used as the support layer.The PES was coated with a thin layer of film on the PES support layer(3%PDMS,dip coating time 5s),and the PES-PDMS hollow fiber gas separation composite membrane with good separation effect was prepared.(3)The diameters,average pore size,SEM,gas flux and gas selectivity of PES hollow fiber membranes and the N2,O2,CO2 pure gas fluxes and selectivity of the composite membrane were obtained.The flux of composite membrane CO2 was 633GPU,And the selectivity reaches O2/N2=2.3,CO2/N2=10.5.Achieved the requirements of air conditioning equipment in the preservation of mango,and making the basic work for the design and processing of the membrane module.