Application of cathodic protection method on steel structures using sacrificial anode and sodium polyacrylate-sodium carboxymethyl cellulose (PANa–CMC) hydrogel electrolyte

Abstract

An ionically conductive sodium polyacrylate-sodium carboxymethyl cellulose (PANa–CMC) hydrogel electrolyte was developed for the sacrificial anode cathodic protection (SACP) of carbon steel in high-humidity environments. The incorporation of varying ratios of CMC into hydrogel formulation enhanced the water retention capacity, adhesion strength, and electrochemical performance, making it suitable for SACP applications. Particularly, PANa-5% CMC hydrogels demonstrated a current density of approximately 3 μA/cm², inhibited passive corrosion product formation, and sequestered metal ions from anodes, thus minimizing contamination. These findings highlight the substantial potential of PANa–CMC hydrogels as electrolytes, expanding the application of the SACP method to atmospheric environments.