dc.description.abstract | In this dissertation, simple and effective solution-blowing and air blowing-assisted electrospinning techniques are presented, by which ultra-thin polyacrylonitrile (PAN) fibers and polycarbonate (PC) nanofibers are prepared and their applications for adsorption of liquid and air filtration are thoroughly examined. In the first part, a solution-blowing process is used to prepare ultra-thin PAN fibers and then the effects of the amount of KOH and carbonized temperature on the preparation of the high-surface-area PAN-based activated carbons are investigated. The high-surface-area PAN-based activated carbons are used to explore the adsorption performances of carbon dioxide (CO2) of post-combustion process. In the second part, a solution-blowing process is used to prepare ultra-thin PAN fibers and then the effects of stabilization temperature on the preparation of the high-surface-area PAN-based activated carbons are investigated. The high-surface-area PAN-based activated carbons are used to explore the adsorption performances of aqueous nonylphenol (NP). In the third part, an air blowing-assisted electrospinning process is used to prepare PC nanofibers and then the effects of air blowing pressure, applied voltage, polymer feeding flow rate and PC solution concentration on the physical properties of fibers and the filtration performance of the nanofiber web are investigated. The investigations include the effects of PC solution concentration and air blowing pressure on morphology such as the fiber diameter and bead density, the effect of fiber diameter on the mean flow pore size and Frazier air permeability of nanofiber mat, and the effect of mean flow pore size on filtration efficiency of nanofiber mat/PP non-woven web. Based on the experimental results, the high-surface-area PAN-based activated carbons and PC nanofiber mats with high filtration efficiency are sucessfully obtained using the solution-blowing process and the air blowing-assisted electrospinning process, respectively. The surface area of the PAN-based activated carbon can be over 2500 m2 g-1 and the adsorption amounts of NP can reach as high as 287 mg g-1, respectively. The ultra-thin PAN fibers stabilized at 533 K achieved the highest CO2 gravimetric equilibrium capacity of 5.53 mmol g-1 in a binary mixture of 15% CO2 in N2 at 323 K, while AC493 had the highest CO2 dynamic adsorption of 2.70 mmol g-1 in a N2/CO2/H2O mixture (83/10/7 % v/v) at 323 K. High filtration performance PC nanofibers, with an average fiber diameter of about 170 nm, can be obtained using an applied voltage of 40 kV, an air blowing pressure of 0.3 MPa, a PC solution concentration of 16%, and a tip-to-collection-screen distance of 25 cm.
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