奈米碳管薄膜之表面改質與導電特性

Surface decoration and characterization of transparent carbon nanotube films

李一凡(Yi-Fan Li)

指導教授 ： 徐文光

國立清華大學/工學院/材料科學工程學系/博士(2010年)

https://doi.org/10.6843/NTHU.2010.00030

摘要

Abstract

The works presented in this thesis discuss the direct exposure of carbon nanotubes to xenon excimer ultraviolet irradiation and effects include change in surface tension, contact angle and state of coating carbonaceous impurities. Irradiated carbon nanotubes are then mixed with polymer and tested as cation collector. Meanwhile, we also discuss the effects of NH3 decoration on nanotubes and an effective technique with electromagnetic application is therefore developed to modulate proton concentration on tube surfaces and verified by microscope analyses. In the end, an enhanced shielding effectiveness is detected at unpurified carbon nanotubes coated film and odd-alternate -radicals sealed within carbonaceous materials are found capable of enhancing adsorption mechanism and underlying mechanism is discussed.

Chapter 1 introduces the background of carbon nanotubes in this thesis, including the structure, electronic properties, chemical properties such as covalent and non-covalent modification, and nanotube synthetic method.

Chapter 2 describes the experimental methods and characterization techniques employed in this study.

Chapter 3 discusses the effects arising from direct exposure of carbon nanotubes to the xenon excimer ultraviolet irradiation at ambient environment and tube surfaces are found decorating with abundant carboxylic groups bound to lattices, hence improving tube surface tension and wetting.

Chapter 4 demonstrates formation of an electric double layer on carbon nanotubes via NH3.H2O treatment upon electric field application and tube wetting is therefore improved. Proton concentration on tube surfaces can be further modulated by a Lorentz force and is verified by multi-transition of hydrophobic into hydrophilic phase.

Chapter 5 discusses the contribution of odd alternate -radicals encapsulated carbonaceous impurities to enhanced shielding effectiveness at radiofrequency and polyethylene terephthalate films coated with pristine and purified single-walled carbon nanotubes are tested and compared.

Chapter 6 concludes the results of our experiments.

摘要

本論文主要探討在大氣底下氙紫外光燈射照對奈米碳管的表面性質之影響，例如碳管表面張力的明顯變化以及表面雜質的去除。而照射後的奈米碳管也將可應用於奈米碳管複合材的合成以及汙水中重金屬離子的吸附。而另一研究則是探討利用氨水修飾奈米碳管薄膜並藉由電磁場的交替運用來改變薄膜表面的質子濃度進而調控液珠在薄膜表面的潤濕情況以及遷移速度。最後則是討論在無線電頻率下，未純化的碳管所合成的奈米碳管薄膜的電磁波遮蔽效果較純化的碳管佳的原因，而相關機制也將於此探討。

第一章
首先簡介奈米碳管的基本性質，如結構，電性，化學性質以及前人對於碳管氧化機制以及電潤濕機制的論述。

第二章
在進入主題前，本章節先介紹實驗設置以及所使用的儀器和實驗步驟。

第三章
此章節主要探討利用氙紫外燈的直接照射來去除碳管表面雜質以及使得碳管表面官能基化，並藉由液珠在碳管表面接觸角變化來計算不同照射時間下碳管表面張力的變化，且透過拉曼光譜、遠紅外線光譜、熱差分析結果、SEM影像等實驗結果來證實。

第四章
本章節介紹透過氨水處理的碳管導電薄膜可藉由電場以及磁場的交替運用來調控液珠在薄膜表面的形狀以及遷移速度，並利用理論計算得知在不同的電磁場運用下,碳管薄膜的表面張力變化。

第五章
此章節說明非晶質碳有助於碳管薄膜在無線電頻率下的電磁波遮蔽效果，並利用未純化以及純化後的碳管製成的薄膜來做比較。

第六章
總結以上各章節的結果。

關鍵字

奈米碳管

參考文獻

Chapter 1

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