Design and manufacture of photoluminescent coatings on stainless steel substrates

Photoluminescent coatings were designed by dispersing SrAl2O4:Eu2+, Dy3+ photoluminescent pigments in a silicone epoxy hybrid binder hardened with a bifunctional silane which possesses a reactive primary amino and hydrolysable ethoxysilyl groups. The resulting emulsions were deposited by an automatic drawdown applicator on AISI 304 stainless steel flat substrates and allowed to dry at ambient conditions. The visual appearance of the coatings was analyzed by combined contact gauge profilometry and field emission gun scanning electron microscopy. Mechanical and tribological properties of the coatings were analyzed by scratch and linear reciprocating ball-on-flat sliding wear tests. Photoluminescence was characterized by capturing high resolution images of the surface with a digital camera and monitoring the decay of the intensity of the emitted photoluminescent radiations. High adherent, durable and partially transparent photoluminescent coatings were achieved with a very simple, reproducible and eco-sustainable process, suitable for a wide range of substrates and large scale applications.