Preparation of surface-modified borax powders for their application in low-temperature vitreous coatings

The objective of this study is to identify the preparation conditions of semi-processed anhydrous borax powders to be used as water-insoluble boron compounds for low-temperature vitreous coatings. For this purpose, the surface modifications of the anhydrous borax (ANB) powders with various silane coating agents, such as 3-aminopropyltriethoxysilane (gamma-APS) and 3-(trimethoxysilyl) propylmethacrylate (gamma-MPS), are investigated. The surface modification-induced changes are characterised by solubility, wettability, dispersibility tests, and thermal and spectroscopic analyses. The results show that when the surfaces of ANB powders are modified with gamma-MPS silane, their interaction with water is significantly prevented, their degree of hydrophobicity is increased, and their water solubility is reduced. The spectroscopic analyses demonstrate that silane coating agents are absorbed on the surface of the ANB powders. The gamma-MPS silane-modified ANB powders offer valuable contributions into a defect-free coating on the surface of ceramic substrate accompanied by complete melting of the coating at a temperature as low as 1050 degrees C. As a result, the silane coating agents could be implemented on the ANB powders to obtain functionalised properties for water-based applications.