Development of Low-Thermal Emissivity Coating Using Aluminum Particles

In this study, low-thermal emissivity coatings were developed using aluminum leafing particles dispersed in an acrylic binder. The aluminum particles were modified through a ball milling process to enhance their leafing properties, with milling times ranging from 5 to 15 h. The effects of milling time on particle size, morphology, and leafing degree were examined using scanning electron microscopy (SEM) and laser diffraction analysis. Coatings with different particle volume concentrations (PVC) and thickener contents were prepared, and their thermal emissivity was evaluated. Results showed that milling time significantly affected the leafing behavior of the aluminum particles, with longer milling times leading to improved dispersion and lower emissivity values. The addition of a thickener enhanced particle distribution, but excessive concentrations resulted in void formation due to hindered solvent evaporation. The lowest thermal emissivity was achieved at a milling time of 15 hours and 10% PVC, providing valuable insights for the design of effective low-emissivity coatings for thermal management applications.