Gold Nanoparticle in Ceramic Glaze

Abstract

A range of processes is described herein for the preparation of a range of ceramic glazes with traditional firing methods that represents significant efficiency and ecological advancements over existing methods and allows for the replacement of commercial ceramic colorant methods, while retaining the costly equipment and firing methods already used. The process allows for ceramic surface color while breaking standards for minimal amounts of transition metal colorant used. The nanoparticle-based glazes described here add new colors to the known ceramic surface palette and offers greater consumer safety as an alternative to existing coloring processes that use higher concentrations of toxic metal and an increased risk of metal leaching from the final ceramic vessel into its contents (e.g., soil, beverage, food).

1 . A pre-firing ceramic glaze material consisting of:
 a base dry glaze powder; and   a colorant material, the colorant material consisting of an amount of metal nanoparticles, wherein each of the metal nanoparticles is formed of a single element type, and further wherein the amount of metal nanoparticles is formed by loading less than 0.1 percent by weight of an Au NP concentration to produce a the pre-firing ceramic glaze material, wherein the Au NP concentration consists of citrate-stabilized nanoparticles synthesized from HAuCl 4  each nanoparticle having a diameter of less than 100 nm; and   further wherein the pre-firing ceramic glaze material produces an observable color on a ceramic item post-firing in a kiln.   
     
     
         2 . The pre-firing ceramic glaze material according to  claim 1 , the observable color is red. 
     
     
         3 . The pre-firing ceramic glaze material according to  claim 1 , wherein the concentration of Au NPs is equal to or less than 0.015 percent by weight. 
     
     
         4 . The pre-firing ceramic glaze material according to  claim 1 , wherein the base dry glaze powder further comprises multiple non-colorant materials include the following: G200 feldspar, Ferro Frit 3134, Kaolin EPK, flint/silica, wollastonite, and talc. 
     
     
         5 . The pre-firing ceramic glaze material according to  claim 4 , wherein the non-colorant materials are combined by weight as follows: 20% G200 feldspar, 20% Ferro Frit 3134, 20% Kaolin EPK, 19% flint/silica, 15% wollastonite, and 6% talc. 
     
     
         6 . A pre-firing ceramic glaze material consisting of:
 a pre-firing dry glaze powder;   at least one colorant material consisting of metal nanoparticles at a concentration of less than 0.1 percent of a total weight of the pre-firing ceramic glaze material containing both the pre-firing dry glaze powder and the at least one colorant material, wherein the average diameter of the metal nanoparticles is less than 100 nm and further wherein each metal nanoparticle is comprised of a single element type; and   further wherein the pre-firing ceramic glaze material produces an observable color on a ceramic item post-firing in a kiln.   
     
     
         7 . The pre-firing ceramic glaze material according to  claim 6 , wherein the at least one colorant material is selected from the group consisting of gold nanoparticles (Au NPs) and silver nanoparticles (Ag NPs). 
     
     
         8 . The pre-firing ceramic glaze material according to  claim 7 , wherein the observable color is selected from the group consisting of red and green. 
     
     
         9 . The pre-firing ceramic glaze material according to  claim 7 , wherein the at least one colorant material is gold nanoparticles (Au NPs) synthesized from HAuCl 4 .