Synthesis of TiO2 nanogel composite for highly efficient self-healing epoxy coating

Erfan Rezvani Ghomi; Saied Nouri Khorasani; Mohammad Sadegh Koochaki; Mohammad Dinari; Shahla Ataei; Mohammad Hossein Enayati; Oisik Das; Rasoul Esmaeely Neisiany

doi:10.1016/j.jare.2022.02.008

Synthesis of TiO₂ nanogel composite for highly efficient self-healing epoxy coating

J Adv Res. 2023 Jan:43:137-146. doi: 10.1016/j.jare.2022.02.008. Epub 2022 Feb 19.

Authors

Erfan Rezvani Ghomi¹, Saied Nouri Khorasani², Mohammad Sadegh Koochaki³, Mohammad Dinari⁴, Shahla Ataei⁵, Mohammad Hossein Enayati⁶, Oisik Das⁷, Rasoul Esmaeely Neisiany⁸

Affiliations

¹ Department of Chemical Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran; Center for Nanotechnology and Sustainability, Department of Mechanical Engineering, National University of Singapore, Singapore 117581, Singapore.
² Department of Chemical Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran. Electronic address: saied@iut.ac.ir.
³ Department of Chemical Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran; Research and Development Department, Alvan Paint & Resin Production Co., Tehran, 13991-53611, Iran.
⁴ Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111, Iran.
⁵ Department of Chemical Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran.
⁶ Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran.
⁷ Structural and Fire Engineering Division, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, 97187 Luleå, Sweden. Electronic address: oisik.das@ltu.se.
⁸ Department of Materials and Polymer Engineering, Faculty of Engineering, Hakim Sabzevari University, Sabzevar 9617976487, Iran. Electronic address: r.esmaeely@hsu.ac.ir.

Abstract

Introduction: Organic coatings are the most effective and facile methods of protecting steel against corrosion, which shields it from direct contact with oxygen and moisture. However, they are inherently defective and susceptible to damage, which allows the penetration of the corrosive media into the underlying substrates. Self-healing coatings were developed to address this shortcoming.

Objective: The current research aims to develop a coating with superior self-healing ability via embedment of titanium dioxide (TiO₂) nanogel composite (NC) in a commercial epoxy.

Methods: The TiO₂ NC was prepared by efficient dispersion of TiO₂ nanoparticles in copolymer gel of acrylamide (AAm) and 2-acrylamido-2-methyl propane sulfonic acid (AMPS) with the help of 3-(trimethoxysilyl) propyl methacrylate (MPS). The chemical structure, morphology, and thermal properties of the modified and functionalized nanoparticles were assessed by infrared spectroscopy, electron microscopy, X-ray diffraction, and thermogravimetric analysis, respectively. In addition, TiO₂ nanoparticles, nano-TiO₂ functionalized monomer (NTFM), and NTFM/AAm/AMPS in different weight percentages were incorporated into epoxy resin to prepare a self-healing coating.

Results: The results confirmed the successful fabrication of the NC. In addition, the incorporation of 1 wt% NTFM/AAm/AMPS led to homogenous dispersion, enhanced anti-corrosive and self-healing performance with the healing efficiencies of 100% and 98%, which were determined by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization methods, respectively.

Conclusion: The prepared NC was sensitive towards salt concentration, pH, which aids the quick reaction of the TiO₂ NC to corrosive ions, once the cracks occur. In addition, this is a unique feature compared to the other self-healing mechanisms, especially, the encapsulation of healing agents, which can be effective as long as the healing agent is present.

Keywords: Coatings; Hydrogels; Nanogel composite; Self-healing; Titanium dioxide.

MeSH terms

Epoxy Resins*
Nanogels
Polyethylene Glycols*
Polymers

Substances

polyethylene glycol polyethyleneimine nanogel
Nanogels
Epoxy Resins
Polyethylene Glycols
Polymers