Publication Date

2012

Document Type

Thesis

Committee Members

Amir Farajian (Advisor), Bor Jang (Committee Member), Raghavan Srinivasan (Committee Member)

Degree Name

Master of Science in Engineering (MSEgr)

Abstract

Graphene is a unique and revolutionary new nanomaterial. A method for it's production had a U.S. patent application in 2002 (patent issued in 2006), it was produced via mechanical exfolia-tion in 2004, and subsequently the Nobel Prize in Physics was awarded in 2010 for it. These events have sparked a surge of graphene-related research. In order for graphene to be widely studied and incorporated into emerging technologies, a versatile method for large scale produc-tion of high-quality graphene is required. Current methods are either slow or expensive which limits the scale-up of graphene production. Very recently, the liquid phase exfoliation of graphene from graphite has been shown as a promising large scale method for graphene produc-tion with little to no defects or surface oxides.

In this thesis, the liquid phase exfoliation of graphene from bulk graphite is studied through computational simulations and subsequent entropy and rate calculations. Employing molecular modeling programs, the energetics of exfoliation are modeled and calculated (a key aspect to de-termining the overall reaction rate for graphene production). Subsequent entropy calculations allow tabulation of reaction rates over a range of temperatures suitable for graphene production in the laboratory. Solvent effects are included and used to validate the feasibility of exfoliation in solvent. The methods used here allow for calculation of the exfoliation rate under various setup conditions including temperature and solvent. As such, comparing different temperatures and solvents is possible to choose better setup conditions for exfoliation in order to optimize the pro-cess.

In addition to the exfoliation rate predictions, metal-doped graphene is presented as a novel sub-strate for the storage of hydrogen with specific application in, e.g., hydrogen fuel cells. Based on accurate calculations and simulations, the binding energy and weight ratio of hydrogen mole-cules stored on the graphene substrate under various conditions (i.e. hydrogen densities, substrate defects, and various metal-adsorbates) are predicted. Maximum theoretical prediction is on the order of 9 wt% of H2, which meets or exceeds Department of Energy requirements, indicating a very promising result.

Page Count

80

Department or Program

Department of Mechanical and Materials Engineering

Year Degree Awarded

2012

Download


Share

COinS