Frit composition

Table 16.1 Typical enamel frit compositions (%) and a mill addition...

Mesko, M. G., Meaker, T. F., Ramsey, W. G., Marra, J. C. Peeler, D. K. 1997. Optimization of lanthanide borosilicate frit compositions for the immobilization of actinides using a Plackett-Burman/simplex algorithm design. Materials Research Society Symposium Proceedings, 465, 105-110. 

From the almost entire absence of day in this fritted composition, the mixture must altogether be excluded from clay wares, being in fact neither more nor less than glass mixture, which, if submitted to complete fusion, would yield an alkaline glaBS. The heat, however, to which this mixture is axpoeed only admits of a. partial... 

The first attempts in this direction were based on the ceramic practice introduced by Seger. The relative amounts of the components were expressed in molar ratios (related per 1 mole of mono- and divalent oxides) while the components were divided into three groups. The composition of traditional enamels listed in Table 35 can be given as an example. The composition is theoretical, i.e. calculated from the raw material mix composition disregarding the volatilisation losses, and also without mill additions (i.e. the frit composition only). 

Other small molecule species decompose and volatilise. The glass frit fuses, wetting the surface of the functional phase, providing adhesion and sealing of the composite to the substrate. Because of the screen printing process, resolution is modest. Fired film thicknesses, which range from 10 to 50 p.m (0.4 to 2.0 mils), are large compared to thin-fHm microelectronics. Some photosensitive pastes are also ia use. 

Typical frit and mill formulae are given in Table 16.1. Frits are tailor-made for each application so that the most desired properties are at their maximum in each case and thus the formulae presented must be regarded as examples of general composition. 

The catalysts were tested for their CO oxidation activity in an automated microreactor apparatus. The catalysts were tested at space velocities of 7,000 -60,000 hr . A small quantity of catalyst (typically 0.1 - 0.5 g.) was supported on a frit in a quartz microreactor. The composition of the gases to the inlet of the reactor was controlled by mass flow controllers and was CO = 50 ppm, CO2 = 0, or 7,000 ppm, HjO = 40% relative humidity (at 25°C), balance air. These conditions are typical of conditions found in spacecraft cabin atmospheres. The temperature of the catalyst bed was measured with a thermocouple placed half way into the catalyst bed, and controlled using a temperature controller. The inlet and outlet CO/CO2 concentrations were measured by non-dispersive infrared (NDIR) monitors. 

In reality, most real cells are never fully at equilibrium because the two half cells are located on either side of a semipermeable membrane, sinter or frit, such as a thin separator of rubber or terracotta (see Figure 3.14). Because ions transfer, and because the two half cells comprise different electrolytes (e.g. in terms of different concentration, etc.), the compositions of the two half cells change with time. 

The percentages of Sn and Pb were obtained from electrochemical data using additions of Sn02 and PbCOs, ZnO as a reference material and 267 sibca brick (British Chemical Standards). Elec-trochemically calculated values from measurements at three pairs of potentials, using the Sn plus Pb stripping peak in acetate buffer (H), are compared with nominal compositions (nom) of the frits and the composition of the ceramic sample obtained from SEM/EDX analysis [242]... 

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