Electron Beam Manipulation of Gold Nanoparticles and In-situ Observation of Chemical Reaction with TEM

• Main Authors: Chen, Yu-Ting, 陳郁婷
• Other Authors: 游萃蓉
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/58m2v9

碩士 === 國立清華大學 === 材料科學工程學系 === 103 === There are two parts in this thesis. For the first part, the electron beam (E-beam) of a transmission electron microscopy (TEM) was utilized for in-situ synthesizing and manipulating Au nanoparticles with various sizes in HAuCl4 aqueous solution. From experimental observations, the driving force for E-beam manipulation was found to be a function of particle-to-beam distance, mostly contributed by the force of dielectrophoresis. It was observed that the E-beam can attract the Au nanoparticles in the HAuCl4 solution. This contributes to the dipole generated in the Au nanoparticle, induced by the non-uniform positive potential built inside the observation window. On the other hand, this positive potential would induce the repulsion force between the positively charged observation window and the positively charged Au nanoparticles. Therefore, a repulsion behaviour of the Au particle and E-beam was also observed. In this study, the mechanism of the manipulation of particles by electron beam was investigated. By understanding the working mechanism, it is expected this emerging nanotechnology could be applied to the applications of particle manipulation with high spatial accuracy and its in-situ real-time observation. For the second part of this thesis is to demonstrate the feasibility of observing the chemical reaction between solid and liquid at the nanometer scale by utilizing the K-kit. The galvanic replacement reaction between Ag nanoparticles and HAuCl4 aqueous solution was selected as the target reaction for observation. A morphology change of nanoparticles similar to previous reports was observed. In addition to in-situ monitoring the morphology changes of particles, it is demonstrated that energy-dispersive X-ray spectroscopy (EDX) could be used to analyze the liquid sample in K-kit. From the experimental results, if the film-supporting structure (Si) thickness of one side of K-kit was reduced to 100 μm, then the characteristic X-ray of the liquid sample sealed in K-kit could be detected. Therefore, if the EDX results could be compared with the in-situ observation of morphology change of nanoparticle, then the component distribution of different reaction states could be acquired.