Viscometry parallel-plate

Cone/Plate Viscometry Co-Axial Cylinder Viscometry Parallel Plate Viscometry Tensile or Extensional Viscometry Dynamic or Oscillatory Rheometry Morphological Analysis... 

Viscometry is the science of the measurement of viscosity. Such viscometric measurements generally have to do with appl3ong either a force F or a velocity V at a surface in contact with a contained test liquid. The response of this liquid to either the velocity or the force is measured at that surface or at some other nearby surface which is also in contact with the liquid. Examples of the geometries used for this purpose include tubes, parallel plates, cone-and-plate arrangements, and concentric cylinders. Sometimes artefacts arise whereby the presence of these surfaces interferes with the local liquid microstructure, giving apparent slip effects—these win be discussed in detail later. 

Figure 7.24 Viscosity curves for the As Se QQ., glass family from x = 10 (leftmost) tox=40 (rightmost) obtained through beam bending and parallel plate viscometry (image courtesy of [193]).

High viscosities, more than 10 Pa s,canbesatisfactorilymeasuredinthecommercialTMA and it is in this region that the glass-forming liquid is typically shaped. Table 10.2 summarises the way in which TMA has been used for beam bending, indentation and parallel-plate viscometers to cover the viscosity range 10 - 10 Pa s. The TMA indentation and parallel-plate viscometry are described in detail below (Section 10.5.5 and 10.5.6, respectively). 

Figure 10.21 The thermomechanical analysis (TMA) output for parallel-plate viscometry of the National Bureau of Standards (NBS), USA, 710 glass after baseline subtraction.

Figure 10.23 Thermomechanical analysis (TMA) parallel-plate viscometry is used to investigate the behaviour of the oxyfluoride glass 32Si02-9AIOi.5-31.5CdF2-18.5PbF2-5.5ZnF2-3.5ErF3 (mol %) in which nanocrystals are homogeneously nucleated above Tg [39]. Description of the viscosity-temperature curves may be found in Section 10.5.6.

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