Preparation And Properties Of Aramid/graphene Oxide Nanofiber Membrane For Hot Gas Filtration

In recent years,the environment characteristics of air pollution has been transformed more complex.Fine particles and ozone pollution constantly aggravate.The emission levels of sulfur dioxide,nitrogen oxides,PM2.5 is strictly controlled.The demands on the dust emissions from chemical industry,oil refineries,incinerations,metal refining and metal recycling are higher.At present,Imported filter media accounted for the main position in the domestic market.So the development of high temperature resistance,corrosion resistance,high filtration efficiency and low wind resistance performance of the filter material has the vital significance.Aramid fiber?PMIA?has outstanding flame retardancy,electric insulation and thermal stability.There is still a gap between aramid fiber and high temperature resistant materials in the process of practical application.In this thesis we intended to incorporate graphene oxide?GO?into PMIA matrix to improve the performance of PMIA nanofibrous membrane.The composite nanofibrous membrane were prepared by electrospinning technology.First of all,we studied the effect of different adding amount of GO on the PMIA nanofibrous membrane.The results indicated that the GO had strong affinity with PMIA matrix by forming hydrogen bonds.When the loading amount of GO was 1.0wt%,the composite membranes exhibited better thermostability and filtration performance compared with the pure membrane.Secondly,this thesis further discusses the effect of GO on the thermal characteristics of PMIA nanofibrous membrane when the loading amount of GO is 1.0wt%.We attempted to know well the characterization and performance of PMIA/GO nanofibrous membranes by investigating the structure,morphology,tensile failure and the filtration efficiency of the composites membranes.The results show that GO can improved the tensile failure and filtration performance of nanofibrous membrane.After the heat treatment at 210?,the air filtration efficiency of the PMIA nanofibrous membrane and the PMIA/GO composite nanofibrous membrane decreased,but it could be maintained at more than90%and the pressure drop respectively decreased to 46.72Pa and 62.28Pa.After heat treatment at 260?,the air filtration efficiency and pressure drop of PMIA nanofiber membrane were greatly reduced,while the air filtration efficiency of the composite nanofibrous membrane remained at 89.49%and the pressure drop was only 58.94Pa.Finally,we study the corrosion resistance of the composite nanofibrous membrane by putting the membranes in 30wt%H₂SO₄ solution and 10wt%NaOH solution at room temperature for 24h.We found that the breaking strength and elongation of the membranes decreased significantly after processing.On the contrary,the filtration efficiency and pressure drop improved.After the immersion of acid and alkali solution,although filtration efficiency of the composite nanofiber membrane increased to 99%or more,but the pressure drop up to 200Pa or more.It is found that the addition of GO was not obvious improved corrosion resistance of the membranes.