Preparation And Properties Of Novel Nanofiber Composite Filter Materials

In order to significantly increase a local minimum of fractional collection efficiency in the aerosol particle size about 0.3μm(MPPS),and simultaneously make this anticipated gain in the filtration efficiency not overpaid with an excessive pressure drop,we developed a high efficiency low resistance air filter with a novel composite structure,which allowed us to produce filters by stacking multiple thin layers composed of microfibers and electrospun nanofibers,and studied the performance.PAN solution was electrospun into a single PET web with the homemade electrospinning instrument.The main research contents have the following several parts:The design and preparation of the novel composite filter composed of micrometer as well as nanometer sized fibers.This paper analyzed the experimental materials by studying the design and way of choosing raw materials.By studying theoretically the composite structure and the design principle,we designed a novel multiple layer composite structure.Effect of different structure parameters on filtration performance.Nanofiber level(g/layer),the parameters,such as the total amount of electrospun nanofibers,spinning time(min/layer),the gross spinning time,basis weight,the amount of stacking layers and so on,were important to filtration performance of composite filtering materials.This paper discovered that the optimum structure parameters were basis weight 500g/m2,total spinning time 200min,the spinning time of per layer 10min,nanofiber level of per layer 0.24g,total amount of nanofibers 4.8g to achieve the best filtration performance,by weighed all structural parameters.Also,the filtration performance tests showed that the maximum filtration efficiency reached 96.6%for 300nm NaCl aerosol particles,which the maximum pressure drop was only 223 Pa under the face velocity of 32L/min,and the filter presented the excellent filtration performance.The study of main performance on composite filter composed of micrometer as well as nanometer sized fibers.This paper studied the SEM picture,the diameter of the fibers,permeability,porosity,the physical strength and thermal stability and so on.The results showed that the mean diameter of PAN nanofibers was 198.672nm,PET fibers 10.988μm,the mean porosity 15μm,permeability 292.9mm/s.Additionally,by testing the breaking strength and extension at break and thermal stability of 4#with the best filtration performance,it was showed that the breaking strength was 370N,extension at break 35%,and it can endure 300℃ high temperature.