Aloe polysaccharide as an eco-friendly corrosion inhibitor for mild steel in simulated acidic oilfield water: Experimental and theoretical approaches

An effective and biodegradable aloe polysaccharide (APS) was studied as an eco-friendly corrosion inhibitor for mild steel protection in simulated acidic oilfield water (15% HCl), whose inhibition performance was studied by weight loss tests, electrochemical techniques, and surface analysis techniques (SEM, EDX, AFM). The experimental results showed that APS has an outstanding inhibition performance for mild steel in 15% HCl, and exhibited a good inhibitory activity over a wide temperature range. Polarization studies indicated that APS is a mixed-type corrosion inhibitor, and its adsorption mode conforms to Langmuir isotherm. An adsorption-related protective inhibitor film formed on the surface of mild steel was verified and investigated based on its surface analysis and characterization. Quantum chemical calculations and molecular dynamics (MD) simulations were performed for the major monosaccharide components of APS to detect structural adsorption behavior. (C) 2020 Elsevier B.V. All rights reserved.