Polyaniline-modified pencil pH electrodes

Date

6-1999

Degree

Bachelor of Science in Chemistry

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Jose H. Santos

Abstract

REBODOS, ROBERT LOUIE FERMO . University of the Philippines Los Banos, June 1999. Polyaniline-Modified Pencil pH Electrodes.

Adviser: Dr. Jose H. Santos

Polyaniline-modified pencil pH electrodes were fabricated using ordinary pencil lead (Mongol HB). Polyaniline was allowed to electropolymerize on the pencil surface. The electrodes' potential relationship with pH were studied using buffers ranging from pH 1.0 to 13. The potential was due to the surface charge density caused by protonation in the acidic region and deprotonation in the basic region. The electrodes were treated with either a strong base to completely deprotonate the polyaniline before measuring the potential in the acidic range, or a strong acid to completely protonate the film before readings were made in the basic region. Treatments were done to assure similar electrode condition prior to measurements. Three regions of potential curves (acid, neutral, and base) were obtained. Different potential readings were recorded at different temperatures suggesting temperature dependence. Comparison with commercially available pH electrode yielded close pH values for standard buffers especially in the acidic region. The polyaniline-modified pencil pH electrode offers the advantage of sturdiness and lower cost.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

LG 993.5 1999 C4 R43

Document Type

Thesis

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