New glass-based coatings coloured with red pigments for Foamglas® panels

Abstract

Abstract This work describes the design and development of new coloured glass-based coatings for Foamglas ® substrates. Four kinds of pigments were added in different proportions (1 and 5 wt% respectively) to a borate glassy matrix (labelled as G7) by two different mixing techniques; the chosen pigments were goethite (α-FeOOH), acicular hematite (Fe 2 O 3 ) spherical hematite and TiO 2 coated hematite. No interaction occurred between the selected pigments and the G7 matrix and consequently no new phases were formed in the reported experimental conditions. Coatings on the Foamglas ® substrates were sintered at 560 °C for 1 h and showed different porosity, pigment dispersion in the matrix and colour development, depending on the mixing technique. The porosity was exploited to add TiO 2 coated hematite into the coating, for photo-catalytic purposes. Each coating was deposited without affecting the Foamglas ® substrate porous structure.