Cellulose acetate (CA) electrospinning was first done at varying concentrations, flow rate and voltage while the tip to collector distance (TCD) was kept constant.The morphology of the electrospun nanofibers under different conditions was then analyzed using SEM to determine the best conditions for electrospinning CA nanofibers.Efficient uniform fiber production was found to be produced at flow rote 0.3ml/h at 15wt.％ CA concentration and 0.4ml/h, at both　　13wt.％ and 15wt.％ CA concentrations for all voltage range used.15wt.％ CA concentrations, flow rate of 0.3ml/h and voltage of 25KV was then chosen for further use in the study.　　During the course of the study, CA solution was left for about 2 weeks without performing any experiment due to the breakdown of electrospinning equipment.On electrospinning the CA solution, it was found that its electrospinnability had reduced.This led to the investigation of the effect of aging CA solution on the morphology of the electrospun nanofibers.CA solutions were aged between 0-30 days and their SEM and FTIR images analyzed.CA solution aged for periods not exceeding 5 days was found to produce finer nanofibers but of relatively lower fiber distribution compared to nanofibers produced from CA solution electrospun without aging.It was also found that aging a spinning solution for 10 days reduced electrospinnability, hence CA solutions should not be kept for 10 days or over. Keeping CA solution for over 20 days, led to complete loss of properties, with nanofiber breakage occurring.Reduced electrospinnability was due to degradation of CA solution.　　CA nanofibers electrospun at 15wt.％ CA, 0.3ml/h and 25KV were characterized.It was found that the CA nanofibers had an average fiber diameter range of 120-130nm and had a relatively uniform distribution.The melting and degradation temperatures were found to be 256.2℃ and 308.4℃ respectively.The Brunauer-Emett-Teller (BET) surface area was 11.75m2/g.The mean pore size was 0.463μm.　　CA nanofibers was then electrospun onto a PP nonwoven material of basis weight 25g/m2, mean fiber diameter of 2-4μm, mean pore size of 15.640μm and filtration efficiency of 50.23％, for 3 hours.A PP nonwoven layer was then added onto CA/PP formed to form a　　PP/CA/PP composite filter and characterized.Nanofibers increased the filtration efficiency of PP nonwoven to 91.29％.Filtration efficiency further increased to 98.26％ when CA nanofiber deposition time was increased to 6 hours.Pressure drop increased from 4.63mmH2O in PP nonwoven material to 55.5mmH2O when CA deposition time was 3 hours. When deposition time was increased to 6 hours, pressure drop significantly reduced to 26.7mmH2O and was attributed to slip flow that occurs to fibers of less than 500nm in diameter.It was also found that electrospun CA nanofibers onto PP nonwoven had larger pores and fiber diameters than those electrospun onto aluminum foil, which reduced CA nanofiber properties and performance.CA nanofibers also lost their narrow pore distribution and fiber diameter distribution.It was concluded that CA nanofibers deposited onto　　nonwovens have a great potential for use in high efficiency particulate filtrations if the thickness on the nano-layer can be increased and the nonwoven charged prior to nanofiber deposition.