Application of amine-functionalized MCM-41 as pH-sensitive nano container for controlled release of 2-mercaptobenzoxazole corrosion inhibitor

In the present study, a pH-responsive corrosion inhibitor system is designed based on aminopropylated MCM-41 as nanocontainer and 2-mercaptobenzoxazole (MBOH) as anti-corrosion agent. This hybrid material shows long-term inhibition capability in 3.5 wt% NaCl solution for Cu and stainless steel. The pH-sensitive composite was prepared via grafting the aminopropyl groups to the surface of mesoporous MCM-41 followed by loading of anti-corrosion agent. The XRD, FT-IR, BET, TGA, TEM, and SEM techniques were used to study the morphological and structural properties of the nanocontainer. The loading and releasing properties of nanocontainer were studied using UV-Visible spectroscopy. The results demonstrate that the minimum release rate of MBOH occurs in neutral condition and that with increase of acidity or basicity of the media, the release rate of the corrosion inhibitor from mesoporous silica increases. The self-healing property of nanocontainer was evaluated by electrochemical impedance spectroscopy (EIS). The results of the approach in this paper can be used in many applications where active corrosion protection of materials is required. (C) 2016 Elsevier B.V. All rights reserved.