Simple PVC-PPy electrode for pH measurement and titrations
C Masalles1, S Borrós, C Viñas
1Institut de Ciencia de Materials de Barcelona (ICMAB-CSIC), Bellaterra, Spain.
Analytical and Bioanalytical Chemistry
|April 10, 2002
Summary
This study introduces a new cobaltabis(dicarbollide)-doped polypyrrole film electrode for pH sensing. Modified with PVC, the electrode offers rapid, low-cost, and effective pH measurements comparable to commercial glass electrodes.
Area of Science:
- Electrochemistry
- Materials Science
- Analytical Chemistry
Background:
- Development of novel electrochemical sensors for accurate pH determination is crucial in various scientific fields.
- Polypyrrole (PPy) is a conducting polymer with potential applications in sensor technology.
- Cobaltabis(dicarbollide) doping offers unique electrochemical properties.
Purpose of the Study:
- To synthesize and characterize cobaltabis(dicarbollide)-doped polypyrrole (PPy) films on glassy carbon electrodes.
- To evaluate the potentiometric response and suitability of the new material for pH measurements and acid-base titrations.
- To improve the response time of the sensor using a template-assisted method.
Main Methods:
- Galvanostatic deposition of cobaltabis(dicarbollide)-doped PPy films on glassy carbon electrodes.
- Potentiometric investigation in various pH buffers and acid-base titrations.
- Fabrication of a modified electrode using a polyvinyl chloride (PVC) template to enhance response time.
Main Results:
- The cobaltabis(dicarbollide)-doped PPy films exhibit a quasi-Nernstian response (approx. 50 mV/pH unit) over a wide pH range (3-12) with high linearity (r2 ≈ 0.98).
- The initial electrode design showed slow response times, limiting its use in multiprotic titrations.
- Employing a PVC template significantly improved the response time by forming PPy wires, resulting in a rapid and cost-effective sensor.
Conclusions:
- Cobaltabis(dicarbollide)-doped PPy films are promising materials for potentiometric pH sensing.
- The PVC-templated PPy electrode offers a rapid, low-cost, and high-performance alternative to commercial glass electrodes.
- This enhanced sensor is suitable for general pH measurements and monoprotic titrations.
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