Top-Down Formulation of Goethite Nanosuspensions for the Production of Transparent, Inorganic Glass Coatings

This study presents a simple but effective process route for the production of transparent coatings on glass substrates from inorganic pigment goethite. For this purpose, coating suspensions were prepared by wet milling with stirred media mill. A water/ethanol mixture was used as liquid medium to take advantage resulting low surface tension process. In manner, stable particles down 50 nm in size obtained, which already showed significant increase transparency. With regard grinding characteristics, particularly stress energies proved be energetically reasonable. The step performed film deposition, achieving thicknesses range 0.5–2.5 µm via dip coating. Highly obtained applying small nm, exhibited significantly lower scattering loss light (≈3%) comparison around 300 (70–80%). Additionally, color could adjusted through variation drying temperature due conversion goethite hematite dehydration. Since transparency not affected, provides an easy-to-implement adaptation controlling colors.