Electronic Theses and Dissertations

Award/Availability

Open Access Dissertation

Keywords

Nanotubes--Formability; Tubes--Formability;

Abstract

The problem of this study was to investigate the effects of static mixer, carrier gas, carrier gas inlet pressures, and reactor operating temperatures on the mixing ratio of carbon nanotube synthesizing reactor. The methodology included design of static mixers, mathematical modeling, and computer modeling and simulation experiments.

The simulation experiment was performed based on single phase carrier gas modeling due to difficulty and time for three phase fluid modeling. First only nitrogen carrier gas in addition to the other three factors under constant inlet flow velocity and inlet temperature was simulated. Secondly, the same procedure was applied to argon carrier gas.

Three temperature values were extracted at exit of model reactors with internal configuration varied with types of static mixers. The bulk temperature and temperature deviations were calculated. The deviations were then divided by the bulk temperature to obtain the mixing ratios from which the mixing indices were determined. In addition, the stream lines for each treatment were obtained to validate the quantitative mixing indices.

A 4-way analysis of variance (ANOVA) was completed, and the diagnostics check on the transformed data showed that the statistical assumptions were met. Thus, the inferential statistics and conclusions confirming or disconfirming the original research questions and research hypotheses were then determined at significant level of .05.

In conclusion, the baffle static mixer showed significant improvement over the existing reactor in the mixing ratio using single phase buffer gas flow. Also the reactor temperature showed significant effect on the mixing ratio. On the other hand, the type of carrier gas and pressure did not show significant effect on the mixing ratio.

This indicated that the appropriate reactor temperatures in addition to improving the inner configuration of the carbon nanotube growth reactors with static mixers can improve achieving uniform atomic distances between carrier gases, carbon and metal catalyst vapors. In the case of laser and solar methods this can then lead to uniform plume formation, cooling, nucleation, growth, diameter and length of carbon nanotubes. The purity of carbon nanotubes can improve and consequently lead to higher yield and improved productivity of the laser vapor method and other methods of growing carbon nanotubes such as the solar, arc, flame and chemical vapor deposition. This will further contribute to cheaper purification cost and hence the overall price of carbon nanotubes.

Date of Award

2005

Degree Name

Doctor of Technology

Department

Department of Technology

First Advisor

John T. Fecik, Chair

Second Advisor

Ronald E. O'Meara, Co-Chair

Date Original

2005

Object Description

1 PDF file (xviii, 232 pages)

Language

EN

File Format

application/pdf

Share

COinS