Coloration of aluminum pigment using SiO₂ and γ-glycidoxypropyltrimethoxysilane with dichlorotriazine reactive dye

Abstract

Purpose The purpose of this paper is to colour aluminium pigment to the highest chroma using SiO2 and organic silane with dichlorotriazine reactive dye and investigate its reaction mechanism, chemical stability and thermal properties to improve its applicability in surface coatings. Design/methodology/approach Aluminium pigment was encapsulated by the catalysed sol-gel method using SiO2, followed by modification with γ-glycidoxypropyltrimethoxysilane (GPTMS). Purified reactive dye (1-Amino-4-[3-(4,6-dichlorotriazin-2-ylamino)-4-sulfophenylamino]anthraquinone-2-sulfonic acid (X-BR)) was covalently immobilized onto modified SiO2 to obtain coloured aluminium pigment. The reaction mechanism, chemical stability and thermophysical properties were investigated by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy, X-ray diffraction, scanning electron microscope, transmission electron microscope and thermogravimetric analyses (TGA). Findings The results showed that X-BR was covalently attached to modified Al/SiO2 with maximum colour grafting of 95 per cent when the dosage of GPTMS and X-BR per weight of modified Al/SiO2 was 25 and 15 per cent, respectively, at pH 8.5 and a temperature of 40°C. The coloured aluminium pigment had good chemical stability with excellent anti-migration properties in many solvents. Research limitations/implications The organic silane used required a careful control of pH to ensure maximum colour grafting efficiency meanwhile other silanes with amine groups could also be used effectively with different kinds of colorants besides reactive dyes. Practical implications The method used is less cumbersome and provides a simple route to preparing coloured aluminium pigment. Originality/value The use of organic-inorganic SiO2/γ- GPTMS with purified reactive dye to covalently colour aluminium pigment to the highest chroma is novel and will help advance the frontiers of knowledge on coloration of aluminium pigments.

Preparation of the Yellow-Colored Aluminum Pigments with Double-Layer Structure Using a Crosslinked Copolymeric Dye

“…The O1s and C1s elements at 285.1 and 536.3 eV can also be observed, which could be attributed to the residual higher fatty acid or solvent oil used in the manufacturing process of aluminum pigments. After being modified with TEOS, the spectra showed new peaks at binding energy of 103.1 and 151.5 eV (Figure 5b) [30], which were ascribed to Si2p and Si2s. The content of Al element decreased from 49.78% to 3.93% and the C element decreased from 25.4% to 12.25%.…”

Overview of Silica-Polymer Nanostructures for Waterborne High-Performance Coatings

“…For example, 3-aminopropyl triethoxysilane (APTES) is widely used to bind to epoxy resins [ 74 , 75 , 76 ] and polyurethane [ 77 ], increasing their performance, or even as grafting sites for RAFT agents [ 78 ] and ATRP initiators [ 79 ]. On the other hand, functionalizing SNPs with γ-(2,3-epoxypropoxy)propyl-trimethoxysilane (GPTMS) can increase the compatibility of the inorganic component within epoxy resins [ 80 , 81 , 82 , 83 , 84 ]. GPTMS can be further modified into carbonate functionalized silanes (4-((3-(trimethoxysilyl)propoxy)methyl)-1,3-dioxolan-2-one, CPS) increasing polyurethane-based coatings performance [ 85 ].…”

Graphene oxide used as the modifier to prepare silica‐encapsulated waterborne flaky aluminium for enhanced anticorrosive property

“…Numerous techniques exist that include inorganic coating [3, 4], organic coating [5] and organic–inorganic hybrid coating [6, 7]. Encapsulation with silica to form a stable core–shell structure has shown to be one of the most practical and stable surface modifications [8, 9].…”