Preparation of Nonsolvent-Induced Macroporous Electrospun Fibers and Their Adsorption Behaviors

• Main Authors: Po-Yu Chen, 陳柏瑜
• Other Authors: Shih-Huang Tung
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/2tdsue

博士 === 國立臺灣大學 === 高分子科學與工程學研究所 === 105 === Electrospinning technique is a straightforward method to produce continuous micro/nanoscale fibers. The common method for manufacturing porous electrospun fibers is vapor induced phase separation (VIPS). However, because the moisture condenses as water drops mainly on top of the solution, the remaining pores are generally isolated and only formed on the surface. Thus the increase of the specific surface area of fibers produced by the VIPS method is limited In this study, the polystyrene/chlorobenzene/DMSO ternary system successfully produce a series of nonsolvent-induced porous fibers. The distribution of the pores was 50 to 2000 nm. The fiber size and the porous morphology can be simply controlled by adjusting the compositions of solvents and organic salt. The fibers with macroporous structure throughout can be fabricated by a simple one-step electrospinning process from the ternary system, without post-spun treatment. Furthermore, we used the co-axial electrospinning technique to adjust the pore structure by controlling the feed rates of inner and outer flows, which can produce a variety of porous structures, including the uncommon hollow porous fibers. Since PS is a hydrophobic but not an oleophobic material, the PS fibrous sorbents can selectively adsorb oil while repelling water. The microscale opening porous structures greatly enhances the oil adsorption capacity of the fibrous sorbents. The maximum adsorption of silicone oil was up to ~ 900 g/g, as well as significantly increases the adsorption rate, giving a considerable leap from the previous studies. The air pollutant adsorption tests were also conducted using different types of fibers as filters to understand the relationship between the fiber structure and the adsorption efficiency of aerosols. The design principles for applying appropriate fiber structures to different forms of pollutants are proposed.