Effects of ethanol vapor exposure on the resistivity and I-V characteristics of electrochemically-synthesized polypyrrole films

• Main Authors: Capirol, Ria Adel, Mejia, Kathlyn M.
• Format: text
• Language: English
• Published: Animo Repository 2014
• Subjects: Pyrroles; Ethanol
• Online Access: https://animorepository.dlsu.edu.ph/etd_bachelors/11909
• Institution: De La Salle University

Conducting Polypyrrole films were electrochemically - synthesized at constant current and temperature in aqueous solution containing 0.1 M pyrrole monomer and varying concentrations of NaPTS (0.08, 0.10M and 0.12M). The films were characterized using EDXA to determine the elemental composition and SEM to determine the surface morphology and film thick ness. Measured film thickness ranged from 0.5883 um to 35.50 um. Film resistivities in air were determined using Van der Pauw technique and were found to range from 0.2012 ]CM TO 10.53 ]CM. Upon exposure to ethanol vapor, the resistivity of the Polypyrrole films decreased significantly. The calculated fractional change in resistivity ranged from 76.36% to as high as 99.40% which shows that the Polyoyrrole films synthesized in this study are highly sensitive to ethanol vapor and could be a very good material as an ethanol sensor. Based on the I-V curves, the resistance of the films showed a significant drop upon ethanol vapor exposure. The calculated fractional change in resistance ranged from 60% to 91%. The sample with the highest resistivity in air showed the highest fractional change in resistance and the sample with the lowest resistivity in air showed the lowest fractional change in resistance.