Thixotropy

thixotropy [thik′sä·trə·pē]

(physical chemistry)

Property of certain gels which liquefy when subjected to vibratory forces, such as ultrasonic waves or even simple shaking, and then solidify again when left standing.

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Thixotropy 

the ability of certain structured disperse systems to revert spontaneously to an initial structure that had been disrupted by mechanical action.

Thixotropy is manifested in gels, pastes, suspensions, and other systems with coagulation disperse structures. Such systems liquefy when shaken or stirred with sufficient intensity and then thicken or harden after the mechanical action stops. Thixotropic restoration of structure is a mechanically reversible, isothermal process that can be repeated many times. In the broader sense, thixotropy is a temporary reduction in the effective viscosity of a viscous fluid or plastic system that results from deformation of the system and is independent of the physical nature of the changes occurring in the system.

Thixotropy is of great practical importance. Thixotropic materials are used in the technology of silicate and plastic technology and in food engineering. Some soils (quicksands), biological structures, and technological materials (drilling muds, paints, greases) also have thixotropic properties.

REFERENCES

Voiutskii, S. S. Kurs kolloidnoi khimii, 2nd ed. Moscow, 1975. Page 317.
Nauka o kolloidakh, vol. 1. Edited by H. R. Kruyt. Moscow, 1955. (Translated from English.)

L. A. SHITS