奈米碳管/二氧化鈦/聚丙烯腈電紡絲複合材料之製備與性質分析

Preparation and properties of electrospun MWCNT/TiO2/PAN nanofiber composites

翁偉芃(Wei-Peng Weng)

指導教授 ： 徐文光

國立清華大學/工學院/材料科學工程學系/碩士(2010年)

摘要

TiO2奈米顆粒之液相懸浮光催化反應時常伴隨著顆粒團聚、沈澱、難以回收等缺點，透過將TiO2負載於高分子聚合物纖維上，可有效改善上述問題。本實驗利用電紡絲製程，並以成絲性佳的聚丙烯腈(PAN)為基底，混入多壁奈米碳管及P25二氧化鈦粉體，製備奈米纖維複合材料，以改善奈米顆粒於液相懸浮光催化之缺點。
文獻報導指出多壁奈米碳管對自由基具有清除作用，添加多壁奈米碳管可望能減緩PAN基底受TiO2光催化降解之程度，增進複合材料之長久穩定性。
實驗結果顯示，在適當的參數下，可成功製得直徑約數百奈米的複合纖維，二氧化鈦顆粒均勻地分佈在奈米纖維中，且仍然具備良好的降解能力。亞甲基藍降解實驗中，在反應初期，含有MWCNTs及不含MWCNTs之樣品對亞甲基藍的降解能力相當，反應最終，含有MWCNTs之樣品亞甲基藍降解率略低於不含MWCNTs之樣品，但降解率差距微小。此外，樣品於五輪降解中皆保有90%上下的亞甲基藍降解能力，顯示本實驗所製備之光催化奈米纖維複合材料，具有良好的重複使用性。於UV下照射20小時後，含有MWCNTs的樣品較不含MWCNTs的樣品，擁有較為完整的纖維形貌，由亞甲基藍降解實驗，90%以上的MB在照射UV四小時後皆已被降解，故就實際應用來說，加入MWCNTs對於複合材料於紫外光照射下，提供了足夠的穩定性。

關鍵字

奈米碳管 ； 電紡絲 ； 奈米纖維 ； 二氧化鈦 ； 光催化 ； 複合材料

並列摘要

Liquid-phase suspension photocatalysis of TiO2 nanoparticles usually accompanies drawbacks such as particle agglomeration, UV hindrance and difficult recovery process. Immobilizing the nanoparticles on polymeric fibers provides an effective solution to these problems.
In this study, electrospun PAN-based nanofiber composites containing MWCNTs and P25-TiO2 are prepared, in order to eliminate the drawbacks regarding liquid-phase suspension photocatalysis, and to enhance the long-term stability of the composites.
Under appropriate experimental parameters, composite fibers with diameter of few hundred nanometers are successfully produced. TiO2 particles are uniformly embbed in the nanofibers, and the composites still exhibit superior photocatalytic performances.
The Methylene Blue (MB) photodegradation efficiencies are comparable between samples containing MWCNTs and those without MWCNTs. Besides, the nanocomposites possess reusability; MB degradation efficiency is maintained at approximately 90% during 5 runs of use for both samples. Furthermore, upon 20 hours UV irradiation, the composite containing MWCNTs shows less damaged fiber morphology than that without MWCNTs. According to MB degradation experiment, over 90% MB are degraded upon 4 hours UV irradiation; hence, the addition of MWCNTs provides sufficient stability to the composites.

並列關鍵字

Carbon nanotubes ； Electrospinning ； Nanofiber ； TiO2 ； Photocatalysis ； Composite

參考文獻

9. 林坤賢, et al., 以電紡絲製備奈米纖維. 化工, 2005. 52(5): p. 22-39.

1. J.H. Carey, J. Lawrence, and H.M. Tosine, Photodechlorination of PCB's in the presence of titanium dioxide in aqueous suspensions. Bull Environ Contam Toxicol, 1976. 16(6): p. 697-701.

2. D.M. Blake, Bibliography of work on the Photocatalytic Removal of Hazardous Compounds from Water and Air. 1999.

4. A. Fujishima, K. Hashimoto, and T. Watanabe, eds. TiO2 Photocatalysis. 1999: Tokyo.

5. I. Sopyan, et al., An efficient TiO2 thin-film photocatalyst: Photocatalytic properties in gas-phase acetaldehyde degradation. Journal of Photochemistry and Photobiology a-Chemistry, 1996. 98(1-2): p. 79-86.