溶液噴紡及氣流靜電紡絲超極細纖維及其應用

The preparation and application of ultrafine fibers by solution blown and air blowing electrospinning technique

蕭弘毅(Hung-yi Hsiao)

指導教授 ： 陳暉

國立中央大學/工學院/化學工程與材料工程學系/博士(2012年)

摘要

本論文主要利用溶液噴紡法及氣流靜電紡絲法來分別製備聚丙烯腈(PAN) 超極細纖維及聚碳酸酯(PC)奈米纖維，並提出其在液體吸附及空氣過濾的應用研究。首先第一主題為以溶液噴紡法製備PAN超極細纖維，探討熱穩定化溫度在KOH化學活化製程對製備PAN高比表面積活性碳的影響，並研究其對燃燒排放廢氣中二氧化碳(CO2)的吸附性能。第二主題為以溶液噴紡法製備PAN超極細纖維，探討氫氧化鉀(KOH)化學活化劑用量及碳化溫度對製備PAN高比表面積活性碳的影響，並研究其在液體中對壬基酚(NP)的吸附性能。第三主題為以氣流靜電紡絲法製備PC奈米纖維，研究以氣流壓力、溶液進料速率和PC溶液濃度等參數來製備PC奈米纖維棉網，探討PC溶液性質、PC溶液濃度及氣流壓力對纖維形態的影響，氣流壓力對纖維直徑及形成球珠(bead)纖維的影響， PC奈米纖維直徑對奈米纖維複合棉網的Frazier透氣度及平均孔徑大小的影響，並研究PC奈米纖維複合棉網的平均孔徑大小對空氣過濾性能的影響。在成果上，本論文成功利用溶液噴紡法及KOH化學活化法的製備出具有高比表面積的PAN活性碳及以氣流靜電紡絲法製備高空氣過濾性能的PC奈米纖維。結果顯示，溶液噴紡PAN超極細纖維以280 oC熱穩定化、KOH與PAN重量比例為3及碳化溫度900 oC處理，得到PAN活性碳的比表面積為2834 m2/g，對液體中壬基酚的吸附容量為287 mg/g。溶液噴紡PAN超極細纖維以260 oC熱穩定化及KOH與PAN重量比例為3及碳化溫度900 oC處理，得到PAN活性碳的比表面積為3081 m2/g，對N2/CO2(85/15 % v/v)混合氣流的重量平衡CO2吸附容量為5.53 mmol/g。以220 oC熱穩定化及KOH與PAN重量比例為3及碳化溫度900 oC處理，得到PAN活性碳的比表面積為2366 m2/g，對含水氣之N2/CO2/H2O(83/10/7 % v/v)混合氣流的動態平衡CO2吸附容量為2.7 mmol/g。再者，具有高空氣過濾性能的PC奈米纖維，是以40 kV電壓, 0.3 MPa氣流壓力, 16 % PC高分子濃度及收集板間距為25 cm的氣流輔助靜電紡絲製程條件，得到均勻的PC奈米纖維、窄的纖維直徑分布、小的複合棉網的平均氣流孔徑大小及纖維直徑大約為170 nm，能有效增進空氣的過濾性能。

關鍵字

溶液噴紡 ； 氣流靜電紡絲 ； 超極細纖維

並列摘要

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.

並列關鍵字

ultrafine fiber ； solution blown ； air blowing electrospinning

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