Preliminary studies on the utilization of polyaniline- coated carbon fiber as a potentiometric pH microelectrode

Date

11-2000

Degree

Bachelor of Science in Chemistry

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Jose H. Santos

Co-adviser

Evamarie P Capareda

Committee Member

Roy Roberto Gerona

Abstract

Polyaniline-coated carbon fiber pH microelectrodes were fabricated by electropolymerization of aniline on the carbon fiber surface. Scanning Electron Microscopy (SEM) data revealed a significant change in the surface morphology of the carbon fiber before and after polymerization, consistent with previous reports on graphite-based electrodes modified with polyaniline. The potential relationships of the electrodes with pH were studied using buffers in the pH range 1 2 to 12.8. The potential is derived from the surface charge density caused by protonation or deprotonation of the polyaniline. To have similar conditions prior to potential measurements, the electrodes were treated with strong base or strong acid before potential measurements in the acidic and basic regions, respectively. Effects of electrode size, charge density and temperature on the response of the electrode were also studied Parallel analysis of buffer solutions using a polyaniline-coated carbon fiber microelectrode and a commercial pH glass electrode were performed and statistical analysis of results showed satisfactory agreement between the two electrodes particularly in the acidic range. Due to their small size, the fabricated pH electrodes may be used in measuring the pH of microliter volumes of aqueous samples and may be utilized for in-vivo pH measurements.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

LG 993.5 2000 C4 G66

Document Type

Thesis

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