Porous glasses, graded

Graded porous glasses as limiting case of graded glass composites... 

Materials. Horseradish peroxidase (type II, 200 purpurogallin units per mg protein) and non-porous glass beads (75-150 1 diameter) were obtained from Sigma Chemical Co. (St. Louis, MO). p-Cresol, hydrogen peroxide (as a 30% solution in water) and dioxane (HPLC grade) were obtained from Aldrich Chemical Co. (Milwaukee, WI). The actual H2O2 content was determined spectrophotometrically at 240 nm. 

Porous media are also manufactured from porcelain, glass, silicon carbide, and a number of metals Monel, Inconel, nickel, bronze, Hastelloy C, Stellite L-605, gold, platinum, and many types of stainless steel. Two manufacturers of porous septa are Mott (mottcorp.com) and Pall (pall.com). The air permeabilities of Table 14-23 indicate the relative flow resistances of the various grades to homogeneous fluid but may not be used in designing a disperser for submerged... 

Numerous industrial and domestic applications requiring Instant bonding for metals, plastics, rubbers, wood, glass and ceramics. Widely used for the precision assembly of small mechanical and electrical components, i.e. small bond areas. Special grades are available for bonding difficult materials (porous, polyethylene, some elastomers, etc.). Gel products with improved gap filling properties are also available. 

Glasses may be joined to metals and other glasses by fusion. Often, glass seals must be graded through several glass compositions from one material to another due to differences in their thermal coefficients of expansion. Ceramics may be metallized and then brazed to other ceramics or metals to form hermetic joints. A ceramic-based adhesive that it is possible to use to 150°C is Ceramabond 552 . The adhesive cirres at 120°C however, the cirred material tends to be porous. 

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