PREPARATION OF BLUE VITREOUS PAINT FROM CO3O4 NANOPARTICLES FOR APPLICATION ON STAINED GLASS AT LOW TEMPERATURES AN EXPERIMENTAL

: One of the most important problems facing the restorer in stained glass restoration is the completion of missing glass pieces to which vitreous paints containing metal oxides were applied that require a high temperature for installation, starting from 550 °C and increasing according to the colored oxide nature and the smelter used. The present paper discusses the preparation of blue vitreous paint for nanoparticles Co 3 O 4 to improve its thermal and color properties. It compares the color prepared from the cobalt nano oxide Co 3 O 4 and cobalt oxide CoO mainly used to color the glass blue since the pharaonic periods. Examination and analysis methods , i.e., XRD, FTIR, SEM, EDX, and TEM, were used in characterizing the cobalt nano oxide. STEM, SEM, and stereo microscope were used to study the prepared color samples. Results showed that the particles size of the prepared Co 3 O 4 of 0.78 nm gave an excellent blue color when applied to the glass at a temperature of 620 °C compared to the color resulting from CoO, which was installed at a temperature of 700 °C according to mixing rates. That paved the way for reducing the proportion of the smelter in the color mixture to increase color resistance to weathering deterioration factors, especially moisture. of 620 °C; 80 °C lower than the color obtained from CoO , which allowed reducing the percentage of smelt in the color mixture. These properties help in facilitating the color completion of stained glass panels, which is an important problem facing the restorer during the restoration of archaeological glass panels. They also enhance the resistance of glass panels to weather deterioration factors, esp ecially humidity. Therefore, this study can con-tribute and pave the way in reserving stained glass panels considered a great part of the history of art.