Functionalization of a Variety of Carbon Surfaces with Transition Metal Complexes: Glassy Carbon, HOPG and SWNT

Posted May 14th, 2010 at 10:39 am.

Eden McQueen

Mentor: Dr. Jonas Goldsmith

The behavior of several carbon surface types functionalized with the compound below (1) will be explored.

mcqueen_fig

A sample of complex 1 was synthesized and re-crystallized to obtain a workable powder. Polished glassy carbon, highly oriented pyrolytic graphite, and single-walled carbon nanotubes (SWNT), were functionalized using 1 by dissolving the complex in acetonitrile and exposing the carbon surface to a dilute solution of 1. The HOPG and glassy carbon functionalized surfaces were characterized by the observed redox behavior on an electrode surface using cyclic voltammetry. Experiments used a range of concentrations from 0.1μM to 2.0μM, and were conducted over the period of 1.5 hours. For each data point the reduction peak height was recorded. The equation mcqueen_fig2 was used to obtain the electrode coverage for each data point. The kinetics and thermodynamics of the adsorption process can be determined by an analysis of coverage (Γ) versus time and coverage versus concentration. In order to study the adsorption behavior of 1 on SWNT, an additional step was required to disperse and separate the SWNT material. Suspensions of SWNT were created using several solvents, including Milli-Q water, chloroform, ethanol, and isopropanol. A range of surfactants, SDS, PVP, PVA, and Triton X-100, were also used and compared as to their relative utilities for suspension formation. Suspensions that appeared to be well-distributed were diluted and filtered. Atomic force microscopy was used to characterize the appearance of the SWNT suspensions. The dispersions will also be cast onto metal electrodes to study their adsorption behavior.

Filed under: 2008,Goldsmith, Dr. Jonas,McQueen, Eden by Ann Dixon

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