Potentiostat-Independent Tools for Electrochemical Assessment of Performance of Coatings, Admixtures, and Corrosion Inhibitors

This paper presents a potentiostat-independent approach for the electrochemical evaluation of corrosion inhibitors, concrete admixtures, and protective coatings.
Three prototype tools were developed and demonstrated:

• Inhibitor Performance Meter (IPM): Measures open-circuit potential and corrosion current of rebars in saline media with and without inhibitors.
• Accelerated Corrosion Testing Device: Applies constant potential across coated concrete samples to quantify corrosion-rate suppression.
• Dielectric Testing Setup: Evaluates the dielectric constant of free films (OHP, acrylic, epoxy, polyurethane) as a quality metric.

By eliminating the need for conventional potentiostats, these tools provide accessible, repeatable, and cost-effective testing suited for both laboratory and field conditions.

Key Findings

• Inhibitor concentration correlated with higher OCP (≈ –400 mV → –200 mV) and lower corrosion current (0.16 mA → 0.06 mA), confirming passivation.
• Accelerated corrosion testing differentiated coating performance: epoxy (0 mA), coal-tar (0.4 mA), acrylic (0.6 mA), control (7.3 mA).
• Dielectric constants aligned with polymer chemistry (OHP ≈ 2, acrylic 4–8, epoxy 2.7, polyurethane 2.4), validating measurement consistency.
• The approach bridges lab-scale electrochemical precision and practical field-level validation for infrastructure durability.

A version of this work is presented at CORCON 2025, Jaipur, India.

© 2025 Durgesh Tamhane

Recommended citation: Tamhane D. Potentiostat-Independent Tools for Electrochemical Assessment of Performance of Coatings, Admixtures, and Corrosion Inhibitors. Proc. CORCON 2025, Jaipur, India.
Download Paper