Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/9916
標題: Preparation and Characterization of Polyaniline / Carbon Nanotubes composites
聚苯胺/奈米碳管導電複合材料之製備與電性研究
作者: Lin, Yen-Wen
林彥文
關鍵字: 聚苯胺;polyaniline;奈米碳管;複合材料;carbon nanotube;composite
出版社: 材料工程學研究所
摘要: 
摘要
本質型導電高分子聚苯胺具有高分子質輕、易塑等特性並兼具導電性質,同時其原料取得及合成製備容易,環境穩定性高,並可藉由質子化摻雜效應或適當加工製程增加聚苯胺整體性質,因此聚苯胺是一適當且理想的導電性應用材料。然而聚苯胺導電度相較於其他導電高分子並不突出,限制了其應用範圍,因此本研究以原位聚合法將聚苯胺與高導電性的奈米碳管和奈米級碳黑相混形成奈米複合材料,期望能發揮各成分的優點,進而提升聚苯胺之導電性質。
奈米碳管擁有高長寬比、高比表面積、高韌性及高導電導熱性等優異性質,使其成為新型複合材料補強材的絕佳候選人,然而奈米碳管易聚集且不溶於水或有機溶劑中,因此研究中利用羧化與醯化程序將羧酸基與醯氯基接枝於奈米碳管表面,可使奈米碳管具備溶解特性。此外將奈米碳管與苯胺單體經加熱迴流程序後,兩者間可形成電荷轉移作用力,也可形成具溶解性之奈米碳管。
將上述改質奈米碳管與苯胺單體進行原位聚合程序,製備而成之聚苯胺/奈米碳管複合材料進行型態分析,結果發現當補強物添加至一定量時(≧ 3wt%),複合物表面形態開始觀察到針狀或松果般層狀的連續管狀或球體複合物,此為聚苯胺包覆於奈米碳管或碳黑表面所形成的“core-shell”結構。此外,當奈米碳管或碳黑未經官能基化程序,複合物易發生奈米碳管或碳黑裸露於聚苯胺結構外的現象,若碳管表面有接枝官能基團,則碳管裸露情形明顯減低。
而複合材料電性量測方面,複合材料導電度曲線大部分呈現“先上升,後下降,再上升”的變化趨勢,此與混合率方程式所預測之結果相似,因此推斷複合材料整體導電性變化趨勢應是複合材料形態轉變所影響。就整體導電度而言,添加碳管對於聚苯胺電性提升的效果為:PCNT
Abstract
Polyaniline (PANI), one of the intrinsically conducting polymers (ICPs), contains good processability, excellent environmental stability, and reversible control of conductivity both by protonation and by charge-transfer dopping.However, comparing to other ICPs, the conductivity of PANI is not obvious so that its application is limited. In order to promote the conductivity of PANI, the PANI/carbon nanotubes (CNTs) and PANI/carbon black (CB) nanocomposites was prepared by in-situ polymerization.
CNTs has high aspect radio, specific surface area, excellent thermal and electrical conductivity, so it is one of the best choice for reinforcements. However, CNTs is easily congregate and not soluble in water or organic solution.In this study, due to the presence of Van deer Waal force, surface treated CNTs by grafting carboxylic acid and thionyl chloride is prepared to improve the solubility of CNT. The treated CNT were mixed with aniline to form a charge-transfer complex at 80℃. After the mixture of aniline and CNTs was heated at reflex, the aniline and CNTs may form a charge-transfer complex.
The addition of 3wt% CNTs or CB into polyaniline, the morphology of nanocomposites look like a “core-shell ” structure. It is because PANI covers the surface of CNTs or CB. On the other hand, when CNTs or CB are not functionalization, the phenomena was not clear.
Regarding to the measure for the conductivity of nanocomposites, the curve of conductivity is very complicated as the ratio of CNTs increases. The calculated result based on the rule of mixture shows similar tendency and is related to the change of morphology.
The conductivity of nanocomposites are in the order of PCNT
URI: http://hdl.handle.net/11455/9916
Appears in Collections:材料科學與工程學系

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