Abstract

Polyaniline nanotubes, first synthesized by Parasarathy and Martin in 1994, have been studied extensively in recent years.[1] The study of these nanodimensional particles has been oriented mostly toward an attempt to understand the electrical and magnetic properties surrounding these semi-one dimensional objects and also toward applications for their utilization.[2] The ability to produce these nano-particles chemically but, without a template was first discovered by Wan in 1999.[3] The use of chemical oxidants often produces undesirable byproducts during the reaction. Therefore, we have used this as a launching point in order to first mirror this template-less synthesis in our lab and subsequently produce these same tubules electrochemically. Our in-situ doped polymer nanotubes showed identical spectroscopic and thermal characteristics as is shown in the original paper in which they were produced. Both optical and scanning electron microscopy were performed on the polymer nanotubes samples and both revealed the presence of tubules in large quantities.

The ability of these polymer nanotubes to produce a catalytic effect in the oxidation of aniline to form azobenzene was also investigated. This reaction was monitored by GC/MS and UV-Vis spectroscopy. The polyaniline nanotubes were found to exhibit a slight catalysis in this oxidation by suppression of byproduct azoxybenzene formation.

A different avenue was then taken in defining the changes which these polymers undergo upon heat treatment in different atmospheres. It was subsequently determined that the polyaniline nanotubes can be converted into carbon under an argon atmosphere. Furthermore, the conformational restriction provided by the parent polyaniline nanotubes seem to offer a means by which carbon nanotubes can be preferentially formed when heated to 275°C. This was determined analytically by FTIR spectroscopy and energy dispersive X-ray analysis. Scanning electron microscopy was then again used to provide proof that single-walled carbon nanotubes are formed at 275°C and that multi-walled carbon nanotubes are formed at somewhere between 600-1000°C. These two allotropic forms of carbon are separated by a transition to glassy carbon occurring at 400°C.

Library of Congress Subject Headings

Nanotubes; Polyanilines; Carbon--Synthesis; Polymerization; Carbon--Structure-activity relationships; Amines--Oxidation

Publication Date

1-2005

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 TA418.9.N35 P37 2005

Campus

RIT – Main Campus

Download

Share

COinS