Influence of Rare Earth Composite Phosphate on Surface Free Energy of Ceramic Glaze

Rare earth composite phosphate (RECP) was doped into the ceramic glazes. The contact angle and surface free energy were characterized by the OCA-30 automatism contact angle test system. Through studied the influence of RECP on the surface free energy of ceramic glaze and movement modality of oil on the ceramic glaze in the water, the results show that the ceramic surface free energy increase obviously after dope RECP. Analysis and calculation show that the surface free energy increase mainly profited from the surface hydroxyl groups increase.

Nano-silver induced ceramic coloring via control of glaze interface and phase separation

As a kind of rare materials,nano-silver has broad application prospects in the fields of catalysis,medical treatment,new energy and so on.However,there are few reports on the systematic research of nano-silver in ceramic glazes.In this work,different color ceramic glazes were produced by tuning the nano-silver content and optimizing the firing process.The crystalline phase composition,micro-morphology and elemental distribution of fired glazes were analyzed and discussed in depth.The elemental composition and distribution of the samples were studied.The surface of the glazes with varying Ag contents fired under the reducing atmosphere exhibited blue-white.And the blue color is attributable to Rayleigh scattering that may arise because the phase-separation structures existed in glazes.Interestingly,the color of the ceramic glazes with varying Ag contents changed to golden-yellow when the ceramic glazes were fired under the air atmosphere.Golden-yellow color of the samples fired under the air atmosphere is mainly attributable to the silver nanoparticles,though Ag^(+) may be existed in the glazes.

Substitution of a fraction of zircon by cristobalite in nano hematite encapsulated pigment and examination of glaze application

Hematite pigment has a long history,but it cannot be used for ceramic application,because it must be thermally and chemically stable at high firing temperature when using a pigment in a glaze or ceramic body.Recently,through encapsulated systems,a new pigment with suitable thermal and chemical stability can be obtained by encapsulating hematite crystals into selected silica or zircon matrices.It means that nano-sized red hematite has been encapsulated into the protected phases.Transmission electron micrographs of hematite encapsulated into silica and zircon matrices by sol-gel method show spherical single crystals with diameter of about 5-10 nm.In order to optimize ceramic glaze formulations for application of the synthesized red inorganic nanocomposite inclusion pigment by sol-gel method,four different types of glazes(i.e.,alkalis,borate,earth alkalis,and leaded glazes)have been tested.The results show that the substitution of a fraction of zircon by cristobalite in hematite-zircon pigment produces acceptable stability with red hue.