Mindy Gordon

Abstract

The oxidations of aromatic and aliphatic amines have been investigated to evaluate the catalytic effect of functionalized multiwalled carbon nanotubes. Aniline oxidation by hydrogen peroxide produces very low yields of azoxybenzene; similarly, p-toluidine oxidation produces azoxytoluene after long time periods. When functionalized multiwalled carbon nanotubes are present in these reactions, the above oxidations produced unique products such as azobenzene or azotoluene within a short period. The course of the reaction has been followed by GC/MS that showed a mass number of 198 corresponding to azoxybenzene (without carbon nanotubes) or 182 corresponding to azobenzene (with the nanotubes). The first stage of the oxidation is identified as nitrosobenzene formation which subsequently couples with the parent molecule to produce the azo compound. UV-VIS absorption spectroscopy showed no peak in the absence of the carbon nanotubes; in contrast to a distinct peak at 347 nm when the reaction is catalyzed by carbon nanotubes. The GC/MS data for the p-toluidine oxidation showed a mass spectral peak at a mass number of 226, corresponding to azoxytoluene, which is replaced by 210, corresponding to azotoluene, when the reaction is catalyzed by the nanotubes. In agreement with the above results, the UV-VIS absorption data showed an azotoluene peak at 464 nm. To reduce the unwanted product contribution coming from the outer solution, a carbon nanotube column was configured. In this situation 100% azobenzene formation was obtained when aniline was oxidized. The efficiencies of the different columns range from 50-97% for the p-toluidine oxidation reaction. The oxidations of diphenylamine and methylamine have also been carried out in the column configuration to understand the mechanisms. The results suggest the feasibility of constructing a nanosynthetic machine for generating high yields of products in the above reactions.

Library of Congress Subject Headings

Carbon--Structure-activity relationships; Nanotubes; Amines--Oxidation; Nanotechnology

Publication Date

2003

Document Type

Thesis

Student Type

Graduate

Degree Name

Chemistry (MS)

Department, Program, or Center

School of Chemistry and Materials Science (COS)

Advisor

K.S.V. Santhanam

Comments

Physical copy available from RIT's Wallace Library at TP245.C4 G67 2003

Campus

RIT – Main Campus

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