Schwab powder

Schwab Powder. An older Austrian rifle proplnt consisting of solid grains (0.75mm OD) of NC coated with graphite. The charge was 2,75g muzzle velocity 600m/sec with a bullet weighing 15.8g press 1300 atms Ref Daniel (1902), 709... 

A method apparently fundamentally related to the above is illustrated by the fractional catalytic dehydration of di-2-butanol observed by Schwab and Rudolph.91 The alcohol recovered after partial thermal dehydration upon a film of copper supported on powdered d- or 1-quartz was faintly active in the same sense as the quartz. Similar results were noted after partial catalytic oxidation on the same surfaces. These results have not been explained fully it is possible that each of the two active forms of the alcohol is adsorbed momentarily on the quartz-copper interface the two diastereoisomeric combinations thus formed then react at different rates. The method is not practical in its present form. 

The catalytic activity of a powder catalyst should be proportional to its surface area in case its entire surface is equally effectii-e for the catalytic reaction. On the other hand, this correlation does not apply to catalysts whose active sites are located at crystallographically exceptional positions such as edges and corners of its microcrystallies. Schwab and Rudoloph (99) studied as early as 1934 the Topochemistry in Heterogeneous Catalysis, and concluded that the active sites of several catalysts were located at crystal boundaries in their surfaces. The chief evidence represented by these workers is that in various catalytic reactions, e.g., in the hydrogenation of ethyl cinnamate over different specimens of powdered nickel catalysts, the rates are proportional to a power of the catalyst surface areas lying between 1.8 and 4.0. 

Schwab and Rudolph " prepared chiral catalysts by supporting the metals on the surfaces of ferreted fine powdered optically active quartz crystals, which proved to be active during as3nnmetric dehydrogenation and dehydration of racemic butan-2-ol. The dehydration-dehydrogenation reactions of butan-2-ol (Scheme 2.1.) were carried out in the vapor phase at... 

W. Komatsu, The Kinetic Equation of the Solid State Reaction The Effect of Particle Size and Mixing Ratio on the Reaction Rate in a Mixed Powder System, in Reactivity of Solids (G. M. Schwab, ed.). Am. Elsevier, New York, 1965, pp. 182-191. 

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