Determination of the Structure-Rheological Characteristics

For many catalysts, the measurements described yielded rather modest values for the mean impact viscosity, q 100 g cm/cm. This indicates that the static strength of porous granules may be 10-100 smaller than that of common construction materials, and the impact viscosity is 10,000 times worse. This means that reasonably strong porous ceramics can be quite brittle, which needs to be borne in mind in both manufacturing and quality control. 

Along with the already discussed standard mechanical testing methods, there are highly precise techniques that are used specifically for the measurements of mechanical properties in colloidal 

FIGU RE 5.17 Schematic illustration of the Weiler-Rehbinder plate. 

The classical problem of relating the result of the action to the properties of the medium in the cuvette is solved as follows. Let h and b represent, respectively, the vertical and horizontal dimensions of the plate, and let d be the distance between the plate and side walls. The shear strain is y = x/d. This picture is symmetrical on both sides of the plate. The shear strain, t, can be found from the expression for the force, F = 2bhx, and t = F/2bh. The plot of T = T(y) is then generated, from which one can obtain several parameters. 

the shear modulus, which, within the limits of reversible strain, can be obtained as follows  

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