Thixotropy definition

For satisfactory casting a slip must have certain definite flow properties. No universal rules can be stated, but it has been found, for example, that sanitary earthenware casting-slips operate best with a fairly high fluidity and a moderate thixotropy. Since... 

Recently, the definition of thixotropy has been made more general, it now being applied to any isothermal reversible decrease of viscosity with increase of rate of shear. Hence, some phenomena of anomalous viscosity have been included which, as a matter of fact, are related ones, as was especially commented by Gk)OBEVE, from whose paper we shall borrow a part of the following. 

Amorphous silica lacks a definite shape and an orderly atomic latticework. Types of amorphous silica include glass, vitreous glass fiber, large flocculated silica gel, diatomaceous earth, and opaline phase-fused silica in granular and powder form. These products provide high purity, reinforcement, great surface area, flatting properties, and thixotropy. Fused silica has an extremely low coefficient of linear thermal expansion and has become quite popular, especially in electronics applications. The amorphous silicas are compatible with thermosets, thermoplastics, silicone rubber, and other elastomers. 

Strongly flocculated suspensions usually show much less thixotropy than weaMy flocculated systems. Again, one must be careful in drawing definite conclusions without other independent techniques (e.g. microscopy). 

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