Papers by Keyword: Lead Glass

Abstract: Microwave heating was discovered more than 60 years ago. And nowadays, it became popular for the use as domestic ovens. Microwave has also been utilized for the industrial processes, such as drying and roasting. On the other hand, there have been many applications of microwave, being investigated for materials' processing and environmental technologies. They are attempted to take advantage of some specific characteristics in microwave heating, which differs from that of the conventional one. Rapid heating, internal heating, selective heating are the features to be taken into consideration. Moreover, so-called "non-thermal effect" is the additional feature in which researchers are particularly interested. In this article, it is intended to describe fundamental aspects in microwave heating and introduce some selected topics of research projects performed in our research group. They include researches on fabrication of some functional materials and on handling industrial wastes etc. In this article, it is also intended to interpret the phenomena observed in these applications from the fundamental view points of electromagnetic wave interaction with materials.

Abstract: Lead-based glass samples were fabricated in a laboratory scale using quartz sands that was a by-product of feldspar floatation in Tak Province, northern Thailand, and 20-wt% commercial-grade PbO as the main compositions. A CdS/Se compound of ratios ranging from 1:1 to 1:10 was doped into the glass mixture. The dried powders were well mixed in a ceramic crucible before being melted in an electric furnace at a maximum temperature of 1100°C for 4 hours. Transparent and bubble-free glass samples were resulted after cooling down to room temperature. It was found that the glass colors were changed from colorless to reddish brown by the addition of CdS/Se compound. Physical properties of the samples, such as, color, specific gravity, and refractive index were studied. Specific gravity and refractive index increased with increasing ratio of CdS/Se. UV-VIS-NIR spectra were measured and discussed.

Abstract: Red colored gold ruby glass used for decorations in ancient times was actually gold nanotechnology at work by the addition of gold particles into molten lead glass. Most of high refractive index glasses are based on lead-bearing silicate glass. High refractive index lead glasses (HRLG) made from local sands and lead oxide were successfully fabricated both in laboratory and larger scales. In this study, gold metal was doped into the lead glass mixtures. Morphology of the prepared lead glass was observed using SEM and compared with that of the red colored Ancient Thai Glass (ATG). It was found that the fabricated red colored HRLG yielded similar color and clarity to the red colored ATG. From electron micrographs, the presence of gold in lead glass was in the form of nanoparticles. The optical properties of the glasses were also examined.