利用掃描探針顯微鏡探測二氧化鈦奈米粒子

Observation od TiO2 Nano-particles by Scanning Probe Microscopy

邱千鳳(Qian-Feng Qiu)

指導教授 ： 傅祖怡

國立臺灣師範大學/理學院/物理學系/碩士(2006年)

摘要

本實驗目的在利用原子力顯微鏡(Atomic Force Microscopy, AFM)探測二氧化鈦奈米粒子的形貌；二氧化鈦粒子由台北科技大學所研發的改良式真空潛弧法(Arc-Submerged Nanoparticle Synthesis System, ASNSS)製備，製備出的奈米流體由不同的介電液收集著。筆者採取不同的取樣法與乾燥法，觀察奈米粒子在矽基底與銅/矽基底上是否有不同的聚集或分散行為；接著利用原子力顯微鏡本身內建軟體，分析粒子的尺寸。
利用原子力顯微鏡大氣系統在觀測上的優勢是：易於操作（不需抽真空）、解析度高，可看到樣品表面形貌與粗糙度，搭配分析軟體可作尺寸測量、grain分析與統計、三維顯示……等。但是缺點在於真空度不佳，對於樣品表面的乾淨度不易維持，所以欲達原子層級解析有困難，另外，取一張圖所需的時間長。
實驗結果顯示，排除原子解析度不可達的限制，原子力顯微鏡協助我們觀察TiO2奈米粒子在不同取樣方式的呈現結果，的確對我們的取樣方法的優缺判斷有其貢獻。合適的取樣方法標準是，以AFM影像掃瞄結果判斷：一為在微米尺度下（大尺度）粒子分佈均勻，而即使在小於微米尺度（奈米尺度）下有團簇行為依然是可以被接受的取樣方法；二為判斷粒子的尺寸大小是否為奈米粒子，即粒子徑度與高度均在100nm以下；或是形成的團簇粒子尺寸在微米以下，而且幾乎是均勻大小的尺寸。

關鍵字

原子力顯微鏡 ； 二氧化鈦 ； 真空潛弧法

並列摘要

This experimental purpose is to utilize an atomic force microscopy（AFM）to survey the morphology of titanium dioxide (TiO2) nanoparticles. The TiO2 sample is manufactured by an arc-submerged nanoparticle synthesis system (ASNSS) which was researched and developed by Prof. Ho Chang’s group of National Taipei University of Technology. The TiO2 nanoparticles were collected in different dielectric liquids using the arc-submerged nanoparticle synthesis method. I adopt different ways in sampling and drying to observe TiO2 nanoparticles in silicon and copper / silicon substrates whether or not have different gathering or dispersing behaviors. Then AFM software was used to analyze the size of the TiO2 nanoparticles.
The advantages of AFM in air system are to operate easier than in high vacuum system, observe the morphology and roughness of sample surface, use analytic software to measure size, grain analysis and statistic, 3-dimension display, etc… But the shortcoming lies in the atomic resolution is unachieved because of low vacuity, hardly to maintain the clean of surface. Besides, it is cost much time to get an image.
The experimental results show that AFM images are helpful to distinguish the best ways of sampling and drying in that TiO2-distribution on Si and Cu/Si substrates. For example, in micrometer scale, one way that made the particles distributing uniformly on substrates even that formed clusters. The other way is to judge the size of the particles which are in nanometer, here defines the diameter of nanoparticles under 100nm, or the formed clusters under micrometer size that are uniform.

並列關鍵字

atomic force microscope ； titanium dioxide ； arc-submerged nanoparticle synthesis system

參考文獻

1. Amy L. Linsebigler, Guangqan Lu, and John T. Yates, Jr., ‘Photocatalysis on TiO2 Surfaces: Principles, Mechanisms, and Selected Results’, Chem. Rev. 1995,95,735-758

2. Ulrike Diebold, ‘The surface science of titanium dioxide’, surface science reports 48, 2003, 53-229

10. Fujihira, M., Annu. Rev. Mater. Sci., 1999, 29, 353-380

11. Martin, Y., Wickramashinghe, H. K., Appl. Phys. Lett., 1987, 50, 1455-1457.

13. Leng, Y., Williams, C. C., Colloid Surface A, 1994, 93, 335-341