No abstract

Zinc oxide is transparent inorganic UV absorber and widely used as a sunscreen. But sunscreen on the skin is easily erased by sebum, so zinc oxide with a sebum curing function was studied. In this study, a zinc oxide powder was prepared using zinc chloride and sodium hydroxide via a hydrothermal synthesis method. The process conditions including reaction temperature and sodium hydroxide ratio were determined. Particle size was determined using XRD and SEM, and process tendencies were checked using the gelling test method. When the sodium hydroxide ratio was lower than 58.7 wt%, the gelling time was reduced, and when the temperature was lower than 60 ^o, the gelling time decreased. ZnO and Simonkolleite confirmed that the gelling time was reduced when the mixture comes out.

Currently, the need for high performance heaters for industrial application is increasing, and repeated wear, rapid temperature change, and uneven temperature can cause deteriorating quality and reduced productivity. The ceramic heater in this study consists of a substrate, an electrode layer, and a protective layer, and low-melting temperature glass frit was used for all layers to allow low-temperature processing. As a substrate for the ceramic heater, Si3N4, which is twice as strong as AlN and has excellent wear resistance, was used. As the electrode material, Ag-Pd, which provides good adhesion to the Si3N4 substrate and high electrical conductivity was used, and MoO3 powder was mixed 8 : 2 to make a paste. The MoO3 adjusts the resistance of the Ag-Pd electrode, thereby supplementing the heater performance. Si3N4 powder and glass frit were used for the protective film layer that protects the electrode, and MoO3 was added to unify the materials between the layers.