奈米/微米螺旋碳管對於電磁波吸收與性質之研究

Electromagnetic wave absorption and properties of carbon nanocoils and carbon microcoils

李昭德(Zhao-De Li)

指導教授 ： 張所鋐

國立臺灣大學/工學院/機械工程學研究所/碩士(2011年)

https://doi.org/10.6342/NTU.2011.01801

摘要

由於螺旋碳管具有優異的電磁特性與良好的抗拉強度，因此在電磁波性質之領域受到廣泛地研究，一般而言，電磁波損失可分為反射損失與吸收損失，反射損失最常見的例子便是金屬，本研究希望透過實驗的方式證實螺旋碳管為吸收損失，並且找出螺旋碳管尺寸對於電磁波吸收之影響。
如何發展一套簡單且有效率的成長製程是相當重要的，雖然成長不同尺寸的螺旋碳管已經有許多的方法提出，但是這些成長製程大多都相當複雜，本研究使用氧化鐵與氧化錫組成的溶液式催化劑，利用化學氣相沉積法成長螺旋碳管，成長過程中省略退火的步驟，不僅使得成長更有效率，且透過操控溫度的高低，成功地以相同製程成長出奈米螺旋碳管與微米螺旋碳管。
此外，在電磁波實驗(18~75 GHz)中，發現螺旋碳管之尺寸對於不同頻率的電磁波吸收扮演著一個重要的角色，當電磁波頻率為18~30 GHz，奈米螺旋碳管之吸收能力較佳；反之，當電磁波頻率為30~75 GHz，微米螺旋碳管之吸收能力較佳

關鍵字

奈米螺旋 ； 碳管微米螺旋碳管 ； 電磁波吸收 ； 催化劑顆粒 ； 溫度

並列摘要

Carbon coils have attracted considerable attention and widely studied in electromagnetic field, because of their excellent electromagnetic property and high tensile strength, In general, the electromagnetic wave loss can be divided into reflection loss and absorption loss. The most common example of reflection loss is metal. In this study, we hope through experiments to confirm that carbon coils are absorption loss. And find out the size of carbon coils effect for electromagnetic wave absorption.
A facile and robust method to grow carbon coils will be important. Methods to grow different size of carbon coils have been explored previously, but these entailed complicated processes. Therefore, we use the Fe3O4 and SnO2 to synthesize carbon coils by thermal chemical vapor deposition, and omit the annealing process. It is not only reduce the growth time but also successfully synthesize carbon nanocoils (CNCs) and carbon microcoils (CMCs) by controlling the temperature.
In addition, in the electromagnetic experiments (18~75 GHz), we find that the size of carbon coils play a key role for electromagnetic wave absorption. CNCs have the better absorption of electromagnetic wave in 18~30 GHz, otherwise, CMCs have the better absorption of electromagnetic wave in 30~75 GHz.

並列關鍵字

carbon nanocoils ； carbon microcoils ； electromagnetic wave absorption ； catalyst size ； temperature

參考文獻

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