新型電漿電弧氣凝系統製作奈米粉末之研究

Abstract

本研究嘗試著組裝一台可製作奈米粉末的設備，係藉由文獻和專利的收集，再經改良和設計，以電漿電弧為加熱源。使用電漿電弧為加熱源優點主要是功率大、可氣化各種金屬與陶瓷材料、同時能用於實驗室規模量產。最後分析由腔體內不同位置置放之鋁箔和Cold-trap所搜集之粉末，來評估本自行研製設備的穩定性及其優劣情況。 實驗結果顯示，所得到的TiO 微粒的平均粒徑大約20nm左右。觀察鋁箔所收集之粉末，得知粉末成長10~20倍（相對於Cold-trap收集之粉末而言）。鋁箔放置位置與粉末粒徑大小有關，放置離蒸發源越遠，粉末粒徑越大。每組上半部由於受輻射熱影響較大，所以粉末粒徑較大。本實驗系統製作之TiO2粉末以Rutile相所佔之比率較大，表示製作過程中，由於受輻射熱影響，已經發生相變化。與國外所製作之TiO2粉末比較，本實驗系統能製作比國外TiO2粉末粒徑還小10nm，表示本實驗設備具有相當的潛能。

A laboratory-made equipment was developed and fabricated in this study to produce nanopowder. According to the published papers and patents a new equipment is designed and tested in our department. This equipment uses plasma arc as a heating source. In this heating source, all of the metal and ceramics materials can be vaporized. This equipment is also effective, inexpensive and suitable to a laboratory scale. The collected powders from different positions in the aluminum foil and cold-trap of the chamber were analyzed using SEM and XRD. The characteristic and stability of this equipment was also evaluated. The experiment result shows that the average particle diameter of TiO2 powder is about 20nm. The powder obtained from aluminum foil is 10~20 times the average particle diameter of that obtained from cold-trap. The size of the average particle diameter of powder is related to the position where powder obtained. The far from the vapor source, the larger the average particle diameter of powder. Due to more irradiation, powder with larger particle diameter can be obtained in the upper part of the chamber. In this experimental system, the Rutile phase have more ratios in the powder of TiO2. This shows the powder have changed its phase during fabricating process because of the influence of irradiation heat. Compared with powder of TiO2 obtained from abroad, this experimental system can produce powder with a particle diameter of less than 10 nm. Therefore, this equipment have a good potential to a future study.