製備碳纖維處理揮發性有機物之研究

Preparation of Carbon Fibers for VOCs Removal

黃怡閔(Yi-Min Huang)

指導教授 ： 林文印

國立臺北科技大學/工程學院/環境工程與管理研究所/碩士(2011年)

摘要

碳纖維具有較大表面積及較高吸附量，被廣泛應用於環境工程、生物科技、化工及電子等產業。在處理揮發性有機污染物較顆粒狀活性碳好，而丙酮（acetone）為半導體廠主要排放之揮發性有機氣體，因此本研究探討自製碳纖維特性並觀察對丙酮的吸附量。
本研究使用聚丙烯腈（polyacrylonitrile，PAN）高分子聚合材料為原料，利用電紡絲系統產生次微米級與微米級之纖維，經不同熱處理溫度製備碳纖維後，探討纖維形態變化，並利用吸附丙酮觀察碳纖維吸附量，
研究結果顯示，產生之538nm（5%）及1µm（8%）之PAN纖維，兩者皆在熱處理溫度180℃以上纖維形態因受熱而產生形變情況。在熱處理條件為250℃時，兩者皆有高比表面積分別為2007.4 m2 g-1及1618.1 m2 g-1，但於300℃時兩者比表面積降為240 m2 g-1左右，顯示在300℃時結構可能有塌陷情形，加熱使纖維反應劇烈，微孔貫穿形成中大孔，導致比表面積降低，或因結構呈現石墨化現象導致比表面積減少。
由吸附試驗結果得知，丙酮濃度為1400 ppm，5%PAN製備之碳纖維其吸附量為91.37 µg/g較8%PAN碳纖維87.72 µg/g高；丙酮濃度為500 ppm，5%PAN製備之碳纖維其吸附量為47.93 µg/g較8%PAN碳纖維43.97 µg/g高。由結果得知，吸附量隨著比表面積增加而增加；在相同比表面積下，碳纖維之飽和吸附量隨著丙酮濃度增加而增加。本研究利用低溫製備之碳纖維擁有高比表面積，但須進一步提高微孔體積比例，且須改善碳纖維之熱穩定，提高材料可應用性。

關鍵字

電紡絲 ； 碳纖維 ； 丙酮

並列摘要

The advantages of carbon nanofibers are high specific surface and high adsorption capacity compared with granular carbons. Carbon nanofibers that were produced using this technique offer the potential for wide variety of applications such as filtration for air or water, chemical industry and biomedical application, etc. One of the organic solvents used most frequently by the semiconductor industry is acetone. This paper were investigated the preparation of carbon fibers and application to removal acetone.
An electrospinning system was set up in this study. It was applied to produce PAN fibrous membranes and then prepare of carbon fibers by heat-treated. The purposes of this study included： (a) generating fibers by using electrospinning, (b) preparing carbon fiber by different heat-treated, (c) analyzing the characteristic of carbon fiber, and (d) examining the adsorption capacity of carbon fiber.
Experimental results showed that PAN fibers (538 nm and 1µm) were deformation as heat-treated temperature above 180℃. As the heat-treated temperature was 250℃, both carbon fibers had higher specific surface area with 2007.4 m2 g–1 and 1618.1 m2 g–1, respectively. However, the specific surface area decreased (240 m2 g–1) as the heat-treated temperature increased to 300℃. The reaction at 300℃ might be more violent than 250℃, the fiber structure collapsed and mircopores became mesopores or macropores. As the result of adsorption test, the adsorption capacity of 5% PAN-250℃ carbon fiber was about 91.37 µg/g, which was greater than 8% PAN-250℃carbon fiber (87.72 µg/g) , as the concentration of acetone was 1400 ppm. When the concentration of acetone was 500 ppm, the adsorption capacity of 5% PAN-250℃ carbon fiber and 8% PAN-250℃carbon fiber was 47.93 µg/g and 43.97 µg/g, respectively.
Experimental results indicated that the adsorptive capacity of carbon fibers increased with the increase of influent acetone concentration and specific surface area of the carbon fibers.

並列關鍵字

Electrospinning ； Carbon fibers ； Acetone

參考文獻

郭霈宸，電紡絲技術製備奈米纖維濾材之特性研究，碩士論文，臺北科技大學環境工程與管理研究所，台北，2009。

Aussawasathien, D., Teerawattananon, C., and Vongachariya, A., “Separation of micron to sub-micron particles from water: Electrospun nylon-6 nanofibrous membranes as pre-filters,” Journal of Membrane Science, vol.315, pp.11-19.20, 2008.

Bahl, P. and Manocha, L., “Characterization of oxidised pan fibres”, Carbon, Vol. 12, Issue 4, 1974, pp. 417-423.

Daley, M. A., Mangun, C. L., DeBarr, J. A., Riha, S., Lizzio, A. A., and Economy, James E., “Adsorption of SO2 onto oxidized and heat-treated activated carbon fibers （ACFS）”, Carbon , vol. 35, no. 3, 1997, pp. 41l-417.

Deitzel, J.M., Kleinmeyer, J., Harris, D., and Beck Tan, N.C., “The effect of proecessing variables on the morphology of electrospun nanofibers and textiles,” Polymer, vol. 42, 2001(A), pp.261-272.