Improved properties of epoxy composite coatings enabled by multi-dimension filler materials

Abstract

Nanofillers of various nano dimensions, ranging from 0D (such as SiO₂) to 1D (such as carbon nanotubes) and 2D (such as graphene), are commonly added to epoxy resin matrices to enhance their tribological properties, making them more suitable for various applications such as protective coatings, composites, and adhesives. Beyond solely utilizing single-nano-dimension fillers, 0D/2D multi-dimensional designed materials are more effective fillers for high-performance epoxy coatings due to their rich morphologies and chemistry. In this work, a highly anti-corrosive epoxy-based coating with multi-dimensional fillers of 2D hexagonal boron nitride (h-BN) and 0D mesoporous silica particles (mSi) is prepared and reported. The approach initially involved the sol-gel condensation reaction coating of h-BN sheets with mesoporous silica to obtain hBN@mSi multi-dimensional fillers. This was followed by the introduction of benzotriazole (BTA) as the corrosion inhibitor to hBN@mSi, forming BTA-hBN@mSi, which was later added to the epoxy resin to obtain the composite coating with improved performance. The underlying mechanism for the improved corrosion behavior in the modified epoxy was then explored using various methods. The results show that the increased specific surface area and pore volume of 0D/2D multi-dimensional fillers of hBN@mSi significantly increased in comparison to their single dimensions. This played a critical role in the BTA loading capacity in the filler and hence the anticorrosion performance of the modified epoxy coating. Furthermore, the modified epoxy coating exhibited good thermal conductivity and mechanical properties, making it suitable for various applications where corrosion resistance, thermal conductivity, and mechanical strength are key, such as in the construction of heat exchangers for various industries including chemical processing, oil refining, power generation, and HVAC systems.