以膠體晶體模板及核殼粒子製備具奈米結構之聚苯胺和其環境應答

Fabrication and Environmental Responses of Nanostructured Polyaniline Prepared from Colloidal Crystal Templates and Core-Shell Particles

楊令樂(Ling-Yueh Yang)

指導教授 ： 廖文彬

國立臺灣大學/工學院/材料科學與工程學研究所/博士(2007年)

https://doi.org/10.6342/NTU.2007.03354

摘要

本文探討了兩種以膠體粒子製備具奈米結構聚苯胺的方式、產物聚苯胺環境應答的情形及結構的影響。一種方式是利用均一粒徑的聚苯乙烯膠體粒子以最密堆積自組而成的膠體晶體為模板，吸附十二烷基苯磺酸及苯胺後，於晶體的間隙藉化學合成法聚合聚苯胺。去除模板即得到高品質的聚苯胺反蛋白石。添加十二烷基苯磺酸使得反蛋白石結構收縮率較低，因此可以調整光禁帶的位置。導電度也隨之增加，聚苯胺部分導電度估計為7 S/cm，與文獻值相當。此外，反蛋白石的厚度能由模板的厚度控制。另一種方式是先藉助十二烷基磺酸鈉於聚苯乙烯膠體粒子表面合成聚苯胺薄殼製得核殼粒子，將核殼粒子塗佈於基板乾燥後，直接或先加熱核殼粒子製膜再除去聚苯乙烯，便能得到兩種由厚數十奈米聚苯胺薄殼隨機堆積而成的薄膜，而此兩種薄膜的吸收光譜顯示加熱過程並未對聚苯胺造成顯著影響。環境應答部分包含乾燥氣流(減少含水量)、乙醇蒸氣(澎潤)、氯化氫氣(摻雜)及氨氣(去摻雜)四種測試。因奈米結構具有廣大表面積與物質作用，結構中的空孔又利於物質擴散，所製備的聚苯胺對環境變化十分敏感、電阻應答快速。不同的結構對應答的情形有著顯著的影響。以核殼粒子製成的兩種薄膜中，經加熱製膜程序者聚苯胺薄殼堆積較緊密，故應答表現均較差。而反蛋白石為高度有序的多孔結構，我們亦分析了其與核殼粒子製得(不具規律結構)薄膜應答情形的差異。反蛋白石的光禁帶更提供新穎的感測方向，實驗結果顯示聚苯胺反蛋白石具有以光禁帶變化感測乙醇蒸氣、氯化氫氣及氨氣的潛力。

關鍵字

聚苯胺 ； 膠體晶體 ； 模板 ； 核殼粒子 ； 奈米結構 ； 感測

並列摘要

In this dissertation, we studied two approaches to fabricating nanostructured polyaniline (PANI) using colloidal particles, its environmental responses, and the influence of the structure. One approach was templating polystyrene (PS) colloidal crystals, or close-packed self-assembly of monodisperse microspheres. After the adsorption of dodecylbenzene sulfonic acid (DBSA) and aniline, the polymerization around the PS spheres was initiated by ammonium peroxydisulfate. Removing PS yielded PANI inverse opals of high quality. The use of DBSA resulted in structures having less shrinkage, and thus the position of the optical stop band could be tuned. The conductivity of the inverse opals increased as well, and that of PANI was estimated to be 7 S/cm, comparable to the value in the literature. Moreover, the overall thickness of the inverse opals could be controlled by that of the templates. The other approach first prepared PS-PANI core-shell particles using PS particles as cores, onto whose surface aniline monomers adsorbed with the aid of sodium dodecyl sulfate and were polymerized to form thin PANI shells. The resulting suspensions of the core-shell particles were then drop-cast onto substrates and dried. Two kinds of films composed of randomly packed thin PANI shells of tens of nanometers were obtained by removing PS directly or after the formation of composite films through heating the core-shell particles. The UV-Vis spectra of the films indicate that the heating had no obvious effect on PANI. As for the environmental responses, four tests were included: dry gas flow (decreasing water content), ethanol vapor (swelling), hydrogen chloride (doping), and ammonia (dedoping). The nanostructured PANI was highly sensitive, and the resistance responded fast to different conditions because of the porosity facilitating diffusion and large surface area interacting with substances. The structure was found to greatly affect the response behavior. Concerning the two kinds of films prepared from the core-shell particles, the packing of PANI shells was more compact in the films whose fabrication involved heating; hence the performance was inferior. We also examined the difference between the responses of the inverse opals (highly ordered porous structures) and films prepared from the core-shell particles (disordered structures). Moreover, the optical stop band of the inverse opals could provide a novel sensing mechanism. The results suggest that the inverse opals have the potential of sensing ethanol vapor, hydrogen chloride, and ammonia by the change in the stop band.

並列關鍵字

polyaniline ； colloidal crystals ； templates ； core-shell particles ； nanostructures ； sensing

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