| Particulate matter(PM)from industrial pollution,coal combustion,biomass burning and waste incineration is usually generated at high temperatures.Removing PM particles directly from high-temperature sources is an effective approach to control and solve air pollution.Polymer nanofibers have a great potential in PM2.5 filtration,but they are limited to preventing particulates from being inhaled by humans at room temperature and generally cannot remove PM particles directly from high-temperature sources due to their vulnerable structure.Therefore,the development of high-temperature resistant new polymer nanofiber filter materials has important scientific value and broad application prospects.Considering the fact that polysulfonamide(PSA)nanofibers have good thermal stability and polyacrylonitrile(PAN)nanofibers have excellent filtration performance,this article designed and formed PSA/PAN composite nanofibers,and studied the forming process of composite nanofibers and the influence of process parameters on their morphology and high-temperature filtration performance.The main work contents are as follows:First,the forming process of PSA/PAN composite nanofibers was studied.The PSA/PAN composite nanofiber membrane was prepared by electrospinning technology using PSA syrup and PAN powders as raw materials.The addition of PAN solved the problem of poor spinnability of PSA solution.The results show that the higher the PSA content in the composite fiber membrane,the better the thermal stability of the membrane.When the mass ratio of PSA solution to PAN solution was 6:4,the obtained nanofiber membrane had the most excellent high-temperature filtration performance,the quality factor reached 0.18 at 400?,and it was used as a follow-up research object.The results of thermogravimetric analysis show that the membrane can withstand a high temperature of400°C,which is superior to commercial meltblown polypropylene(PP)membranes and polyvinylidene fluoride(PVDF)membranes.Secondly,the filtration performance of PSA/PAN composite nanofiber membrane was studied.At room temperature,the filtration efficiency of the membrane for NaCl aerosol increased with the increase of the basis weight of the membrane and decreased with the increase of the air flow velocity.When the air flow volecity was 4.8cm/s,the filtration efficiency of the membrane with the basis weight of 10.5 g/m2 reached 98.8%,and the pressure drop was only 35Pa.By calcining the composite fiber at a certain temperature and then testing its filtration performance to study its high-temperature filtration performance.The test results show that the filtration efficiency of the fiber membrane for PM2.5 exceeds99.70%at 400?,and the filtration efficiency for PM2.5-10 exceeds 99.97%.In addition,it could maintain a PM2.5 removal efficiency of over 98%after continuously working for 100hours in an environment with concentration of PM2.5 approaching 380?g/m3.As an example in practical application,we used the PSA/PAN nanofiber filter to remove the PM particles from the automobile exhaust gas,and the removal efficiency achieves 97%.The above results show that the PSA/PAN composite nanofiber membrane has excellent thermal stability and filtration performance,we believe that PSA/PAN composite nanofiber membrane is expect to offer wide application in filtration field,affording people with a fresher and healthier living environment. |
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