Glass encapsulation

Disk thermistors can be produced to close limits of iaterchangeabihty, eg, 0.1 and 0.05° C. Disks cannot be made as small as the smallest beads 2 mm diameter seems an approximate practicable limit. Disks historically have been considered to be less stable than good beads. They are commonly protected with a coatkig of epoxy reski, which provides less compressive support than the glass coatkig of bead thermistors. More recent developments have resulted ki kiterchangeable glass-encapsulated disk thermistors which have the stabihty characteristics of the best beads. 

Magnetic reed contacts are glass-encapsulated magnetically operated reed switches used on doors and windows. The contacts can be overcome by cutting the door, leaving the magnet undisturbed. 

Another commercial thermistor, Thermox (by LakeShore), is useful between 77 K (—80kfl) and room temperature (—0.3 fi). It consists of a glass-encapsulated metal oxide bead. The short-term stability is about 25 mK in the useful range. 

Most tight sources for artificial lighting have a UV component in their emission spectrum. Usually, the glass encapsulation absorbs all radiation below about... 

See also Flavor encapsulation, Glass encapsulation applications of, 11 553—557 encapsulation technologies, 11 530-543, 543-553... 

Donald, I. W., Metcalfe, B. L. Greedharee, R. S. 2002. A glass-encapsulated ceramic wasteform for the immobilization of chloride-containing ILW Formation of halite crystals by reaction between the glass encapsulant and ceramic host. Materials Research Society Symposium Proceedings, 713, 287-293. 

In recent years, specific requirements with regard to shelf-life stability and tailor-made release behaviour led to the development of a range of specific encapsulation technologies such as glass-encapsulated flavours or seamless capsules with liquid cores. 

Composite materials are mechanical dispersions of radioactive solids, for instance ciystalline or vitreous radioactive phases in metal matrix [24], glass-encapsulated Ca-phosphate based ceramics [30] glass-bonded sodalite [31,32] glass-ceramics for plutonium waste immobilization [33] and so on. 

In a series of papers [30-35], Blum and co-workers reported the hydrogenation of alkenes, alkynes, and arenes in the presence of a hydrated ion-pair [0ct3NMe] [RhCl4(H20)n] . The quaternary ammonium tetrachlororhodate also catalyzes HTR of alkynes, alkenes and a,j6-unsaturated carbonyl compounds with polymethylhydrosiloxane [36, 37]. Recently, heterogenized and therefore recyclable quaternary ammonium halometallates, namely glass-encapsulated catalysts [38] and polymer-bound tetrachlororhodate [39], have been described. Both types of the insoluble catalysts effectively promote various processes including the hydrogenation of alkenes and the HTR of a,/9-unsaturated carbonyl compounds [40]. 

J. A. Wise, Stability of Glass-Encapsulated Disc-Type Thermistors, in Temperature Its Measurement and Control in Science and Industry, vol. 6, pt. 1, pp. 481-484, American Institute of Physics, New York, 1992. 

Another promising example of a metal-based sensor can be seen in the work of Lee and Okura (239) who used entrapped platinum octaethylporphyrin complexes to form photostable devices. In their study, they found by adding the surfactant Triton X-100 to the sol-gel mixture, they could improve homogeneity and phosphorescence of the dye-containing glass. Encapsulated porphyrin molecules have also been used successfully in the sensing of nitrogen dioxide (240) and, as will be discussed below, can be used to sense metal ions. 

Mouzon J, Maitre A, Frisk L, Lehto N, Oden M (2009) Fabrication of transparent yttria by HIP and the glass-encapsulation method. J Eur Ceram Soc 29 311-316... 

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