利用流體化床形式的電漿輔助化學氣相沉積進行粉體表面之薄膜沉積

Material Coating on Powder Surfaces by Dielectric Barrier Discharge at Atmospheric Pressure

曾暐升(Wei-Shang Zseng)

指導教授 ： 徐振哲

國立臺灣大學/工學院/化學工程學研究所/碩士(2015年)

https://doi.org/10.6342/NTU.2015.02846

摘要

本研究利用介質放電系統進行粉體之表面披覆，不同型態的電漿能藉由不同的實驗架設及操作參數來形成。介電質放電系統是將至少一層介電質放置於上下電極之間來完成電漿的產生。當前驅物進入電漿系統後，會產生裂解並披覆於粉體表面，本實驗利用不同的實驗設置、前驅物及主粉體來完成粉體的披覆。
首先本研究以乙炔為前驅物進行鋰錳鎳氧粉體以及二氧化矽粉體的表面碳膜披覆，利用電漿進行批覆後以高溫爐進行熱處理，可發現其導電度有明顯的上升，並且利用拉曼光譜儀可看見粉體表面有明顯的G-peak及D-peak，表示我們於粉體表面完成非完美石墨之碳披覆。
其後我們以TEOS作為前驅物進行二氧化矽之表面披覆，本研究先後於氧化鋅及二氧化鈦表面進行二氧化矽薄膜披覆，由傅立葉轉換紅外線光譜儀可得知我們所批覆之二氧化系為有機的類二氧化矽薄膜。並且氧化鋅粉體於二氧化矽批覆後其UV段之發光性質有明顯增益，並且我們可以利用不同的前處理來改變其發光增益之波段。
最後我們以八氟環丁烷 (C4F8) 做為前驅物進行粉體表面的類鐵氟龍薄膜披覆，我們以二氧化鈦及二氧化矽等親水粉體做為主粉體進行批覆。於進行類鐵氟龍薄膜批覆後其親疏水性皆有明顯的改變。
　　並且我們發現，在流體化床當中，粉體的流體化能夠讓粉體被能夠被均勻的批覆並且使得奈米粉體聚集體被破壞，使粉體的行為更接近真實的奈米顆粒。

關鍵字

奈米粉體 ； 披覆 ； 流體化床 ； 電漿 ； 介電質放電

並列摘要

In this work, we synthesize core-shell nanoparticles with different precursor and particles by an ultra-fast, one-step, dry, and atmospheric-pressure plasma fluidized bed process.
Plasma-enhanced chemical vapor deposition (PECVD) has been widely used for thin film surface treatment and surface modification. However, PECVD is difficult to treat particles due to some problem like non-uniform coating and particle agglomeration. The fluidized bed technology has some advantage to treating; for example, well solid mixing and breakage of agglomeration.
First, we coating carbon film with different particle acetylene (C2H2) by as carbon source. The conductivity of coated particle is in significantly enhancement after dihydrogen process.
Then the SiOx film have been coated with Tetraethyl orthosilicate (TEOS) as precursor. An improved ultraviolet (UV) to visible luminescence (better than pure ZnO nanoparticles) was observed from ZnO/SiO2 core-shell nanoparticles by Fluorescence Spectrophotometer. The particles are well-dispersed in ethanol after silica coating due to the increase of zeta potential and breakage of agglomeration.
At last, we use Octafluorocyclobutane (C¬4F8) as precursor to coat Teflon-like film on SiO2 and TiO2 particles. The hydrophilicity of host particle changed significantly after coating.
We believe this fabrication technique brings impact to the field of photocatalysis, battery and emitting device.

並列關鍵字

nano-particels ； coating ； plasma ； DBD ； fluidized bed

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