Degree Type

Thesis

Date of Award

2017

Degree Name

Master of Science

Department

Chemical and Biological Engineering

Major

Chemical Engineering

First Advisor

Yue Wu

Abstract

Two-dimensional mxenes, the newly discovered materials have attracted numerous attractions in batteries, super capacitors and electromagnetic screening, etc. Due to the 2D shape and predicted metallic properties of the material, thermal properties of mxenes are expected to be anisotropic and extremely high. To integrate this material into practical devices, gaining insight of its thermal properties will be helpful for the architecture design. However, none of the actual measurements of the materials are yet reported. In regard of the interest, thermal conductivities of bulk Ti3C2Tx mxene prepared by sparking plasma sintering (SPS) technique was measured. The results showed a high anisotropy in thermal conductivities of the material. This study will expedite the material discovery and device optimization of Mxene material in various fields.

This thesis gives an insight on the preparation of Ti3C2Tx mxene flakes and nanostructured Ti3C2Tx mxene disk sample. Thermal conductivity measurement was applied on the obtained disk sample. In this research Ti3C2Tx mxene flakes are obtained from the MAX Phase Ti3AlC2, which is synthesized from Ti, Al, C powders in the stoichiometric ratio of 3: 1.2: 2 at the temperature of 1400°C. SPS was utilized for the MAX Phase preparation and several different MAX Phases were prepared for studying at the beginning of this project. These MAX Phases included Ti3AlC2, Ti2AlC and Zr3Al3C5.

To study the properties of the mxene phase, obtained MAX Phases are grinded into thin powder, thieved through a 325mech screen, and then etched with 48% hydrofluoric acid. To obtain a Mxene Phase disk, mxene flakes are collected after the etching process. Since the surface functional groups have a great impact on the thermal properties of the Mxene phase the collected flakes are soaked in anhydrous hydrazine after washing with DI water. Hydrazine soaked samples show a quite different thermal property in comparison with the non-soaked samples.

Thermal conductivity of the samples was measured from both the Differential Laser-Heating and Infrared-Imaging(DLI) method and Laser Flash method. The two methods gave similar values on the measurement. The DLI method gives a great illustration on how thermal conductivity of the disk samples can be measured for future relative projects and the behavior of the disk samples shows the anisotropic property of the disks which potentially has many applications.

DOI

https://doi.org/10.31274/etd-180810-6130

Copyright Owner

Huazhang Zhu

Language

en

File Format

application/pdf

File Size

60 pages

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