(from the Greek thixis - touch and trope - turn, change * A. thixotropy of rocks; N. Thixotropie der Gesteine; F. thixotropie des roches; and. capacidad tixotropica de rocas, tixtropia de rocas) - a physicochemical phenomenon that occurs in some colloidal dispersed systems, for example, in cohesive rocks, and consisting in their spontaneous liquefaction under the influence of mechanical action (shaking, stirring, vibration, exposure to ultrasound, etc.) and the subsequent restoration of the structure while eliminating these influences. Thixotropy is explained by the reversible weakening of the structural bonds between the mineral particles of the cohesive rock. Under a certain mechanical action, bound and immobilized water passes into free water, which leads to a decrease in the strength of structural bonds and liquefaction of the rock. Termination of exposure leads to the reverse transition of water from a free to a bound state and hardening of the rock (thixotropic hardening).
Fragility is an indicator characterizing the tendency of rocks to thixotropic softening. It is customary to measure it with the average radius of the base of a cylindrical sample (mm) after vibration at a vibration frequency of 67 Hz and an amplitude of 1 mm. The initial radius of the sample is 8 mm and the height of the cylinder is 20 mm. The value of the fluctuation index varies from 8-9 for non-thixotropic rocks to 15 or more for highly thixotropic rocks. A more general indicator is the structural strength limit under dynamic action, defined as the limiting alternating acceleration at which the rock strength does not decrease. It is measured in m / s 2. Thixotropic hardening is characterized by the recovery time (s), during which the maximum strength of the rock is achieved during recovery.
Thixotropy is determined by the qualitative and quantitative composition of their dispersed phase, the shape of particles and their hydrophilicity, the composition and concentration of pore moisture, etc. The main influence is exerted by the granulometric composition of the rock. Thixotropic phenomena are typical for rocks with a clay particle content of at least 1.5-2%.
Thixotropy is widespread in nature and has both a negative and a positive effect on technological processes in the development of wet cohesive rocks. For example, when transporting such rocks, thixotropic liquefaction causes their intensive adhesion to the working surfaces of the transport equipment, reducing its productivity by 1.5 times. On the other hand, thixotropy is used in drilling and pile driving. Thixotropy is the cause of landslides.
Thixotropy (thixotropy) (from the Greek. θίξις - touch and τροπή - change) - the ability of a substance to reduce the viscosity (liquefy) from mechanical action and increase the viscosity (thicken) at rest.
Thixotropic liquids
Thixotropy should not be confused with pseudoplasticity. For pseudoplastic fluids, the viscosity decreases with increasing shear stress, while thixotropic fluids have a viscosity decreases over time at constant shear stress.
Thixotropic fluids are fluids in which, at a constant strain rate, the shear stress decreases over time.
The viscosity of some fluids at constant ambient conditions and shear rates change over time. If the viscosity of a liquid decreases over time, then the liquid is called thixotropic, if it increases, it is called rheopex.
Both behaviors can occur both together with the types of fluid flow described above, and only at certain shear rates. The time interval can vary greatly for different substances: some materials reach a constant value in a matter of seconds, others in a few days. Rheopex materials are quite rare, in contrast to thixotropic materials, which include lubricants, viscous printing inks, and paints.
Thixotropic liquid
Thixotropic liquids(from the Greek. θίξισ - touch and τροπέ - change) - liquids in which, at a constant strain rate, the shear stress decreases with time.
The viscosity of some fluids at constant ambient conditions and shear rates change over time. If the viscosity of a liquid decreases with time, then the liquid is called thixotropic, and if, on the contrary, it increases, then - rheopex.
Both behaviors can occur both together with the types of fluid flow described above, and only at certain shear rates. The time interval can vary greatly for different substances: some materials reach a constant value in a matter of seconds, others in a few days. Rheopex materials are quite rare, in contrast to thixotropic materials, which include lubricants, viscous printing inks, and paints.
When studying the influence of two parameters (time and shear rate) on the viscosity of materials for thixotropic fluids, the following curves will be obtained. [ clarify]
The descending and ascending curves do not coincide and form a "hysteresis loop", which is caused by a decrease in the viscosity of the fluid during prolonged deformations. This phenomenon can be reversible or not: some systems can regain their initial viscosity after a period of rest, other systems never.
see also
Thixotropy
Rocks (from the Greek thixis - touch and trope - turn, change * a. thixotropy of rocks; n. Thixotropie der Gesteine; f. thixotropie des roches; and. capacidad tixotropica de rocas, tixtropia de rocas) - physical and chemical. a phenomenon that occurs in certain colloidal dispersed systems, for example. in coherent g. p., and consisting in their spontaneous dilution under the influence of mechanical. exposure (shaking, stirring, vibration, exposure to ultrasound, etc.) and subsequent restoration of the structure while eliminating these influences. T. is explained by the reversible weakening of the structural bonds between the mineral particles of the cohesive rock. With a certain mechanical. the impact occurs the transition of bound and immobilized water into free, which leads to a decrease in the strength of structural bonds and liquefaction of the rock. Termination of exposure leads to the reverse transition of water from a free to a bound state and hardening of the rock (thixotropic hardening).
An indicator characterizing the tendency of the g. Item to thixotropic softening is fragility. It is customary to measure it by the average radius of the cylindrical base. sample (mm) after vibration at a vibration frequency of 67 Hz and an amplitude of 1 mm. The initial radius of the sample is 8 mm and the height of the cylinder is 20 mm. The value of the fluctuation index varies from 8-9 for non-thixotropic rocks to 15 or more for highly thixotropic rocks. A more general indicator is the structural strength limit at dynamic. impact, defined as the limiting alternating acceleration, when the rock is not reduced. It is measured in m / s2. Thixotropic hardening is characterized by the recovery time (s), during which the max. rock strength.
T. is determined by qualities. and quantities. the composition of their dispersed phase, the shape of particles and their hydrophilicity, the composition and concentration of pore moisture, etc. Main. influenced by granulometric. composition of the breed. Thixotropic phenomena are typical for rocks with a clay particle content of at least 1.5-2%.
T. is widespread in nature and has both negative and positive. influence on technol. processes in the development of wet cohesive rocks. For example, during the transportation of such rocks, thixotropic liquefaction causes their intensive adhesion to the working surfaces of the transport. equipment, reducing its productivity by 1.5 times. On the other hand, T. is used for drilling and piling. T. is the cause of landslides. A. V. Dugartsyrenov.
Mining encyclopedia. - M .: Soviet encyclopedia. Edited by E. A. Kozlovsky. 1984-1991 .
Synonyms:See what "Thixotropy" is in other dictionaries:
Thixotropia Dictionary of Russian synonyms. thixotropy noun, number of synonyms: 1 thixotropy (1) ASIS Synonym Dictionary. V.N. Trishin ... Synonym dictionary
Thixotropy- - the ability of paint to reduce the viscosity (liquefy) from mechanical impact and increase the viscosity (thicken) at rest ... Builder's vocabulary
thixotropy- The property of some materials of glue, latex, etc. to restore their structure, destroyed by mechanical action [Terminological dictionary for construction in 12 languages (VNIIIS Gosstroy USSR)] EN thixotropy DE Thixotropie FR thixotropie ...
thixotropy- 3.5 thixotropy: The ability of a solution to thicken at rest, forming a gelatinous mass of gel and liquefy under mechanical action, turning into a viscous liquid sol. The process can be repeated many times. A source …
The property of some materials of glue, latex, etc. to restore their structure, destroyed by mechanical action (Bulgarian; Български) thixotropy (Czech; Čeština) thixotropie; tixotropie (German; Deutsch) ... ... Construction vocabulary
thixotropy of a petroleum product- Physicochemical property that determines the change in rheological characteristics at constant temperature as a result of the destruction of the structural framework of a plastic oil product during deformation, as well as further change in these characteristics ... ... Technical translator's guide
soil thixotropy- The ability of some soils and soils in a waterlogged state to acquire fluidity under the influence of mechanical influences (with shaking, stirring) and again go into a solid state at rest ... Geography Dictionary
Soil thixotropy- the ability of some p. and soils in a waterlogged state to liquefy (acquire fluidity) under the influence of mechanical influences (shaking, mixing) and again turn into a solid state when at rest ... Explanatory Dictionary of Soil Science
STO-GK Transstroy 014-2007: Trench wall in the ground. Construction and construction technology for transport construction objects- Terminology STO GK Transstroy 014 2007: Trench wall in the ground. Construction and technology of construction for transport construction objects: 3.15 VCT: Method of placing concrete using a vertically movable concrete-cast pipe. ... ... Dictionary-reference book of terms of normative and technical documentation
- (water dispersion paints, latex paints, emulsion paints), suspensions of pigments and fillers in aqueous dispersions (latexes) of film formers. Aqueous emulsions of the latter receive hl. arr. emulsion polymerization of the corresponding ... ... Chemical encyclopedia
Thixotropy
Thixotropy
The ability of certain dispersed systems to liquefy reversibly at sufficiently intense mechanical. exposure (stirring, shaking) and harden (lose) when at rest. T. is a characteristic property of coagulants. structures that can be destroyed an unlimited number of times, and each time their properties are fully restored. Examples of typical thixotropic structures are systems formed during coagulation of aqueous colloidal dispersions of iron hydroxide, aluminum hydroxide, vanadium pentoxide, bentonite suspensions, and kaolin.
Mechanic the properties of thixotropic structures are characterized by the values of three parameters (P. A. Rebinder): the greatest eff. viscosity h 0 practically intact structure, the smallest eff. viscosity h m maximum fractured structure and ultimate shear stress P 0 .
Dependence eff. viscosity h on the applied shear stress P can be described by ur-niy
For small values P that do not violate rest or cause a very slow flow, the structure has the properties of a solid, since its recovery under these conditions exceeds the rate of destruction. At R>>R 0, the system turns out to be extremely destroyed and has a low viscosity h m... The magnitude P 0 characterizes an unbroken structure. The process of restoring a destroyed structure at rest can be characterized by an increase in strength over time.
In some cases, the application of small P and deformation at a low rate accelerates the growth of strength and structuring of dispersed systems; this phenomenon is called. reopex and e y. Sometimes concentrated dispersed systems (pastes) exhibit dylatans and I - an increase in h with an increase in the deformation rate, accompanied by a certain increase in the volume occupied by the system: upon deformation, solid particles form a looser framework and the existing liquid medium turns out to be not enough to provide the system.
T. dispersed systems has a great practical. meaning. Thixotropic properties must be possessed by greases, paints and varnishes, ceramic. masses, flushing, used when drilling wells, pl. food products. I. H. Vlodavets.
Physical encyclopedia. In 5 volumes. - M .: Soviet encyclopedia. Chief Editor A.M. Prokhorov. 1988 .
Synonyms:
See what "THYXOTROPY" is in other dictionaries:
Thixotropy ... Spelling dictionary-reference
Thixotropy- - the ability of dispersed systems to restore the original structure destroyed by mechanical action. [Terminological dictionary for concrete and reinforced concrete. FSUE "Research Center" Construction "NIIZhB and M. A. A. Gvozdev, Moscow, 2007, 110 pages] ... Encyclopedia of terms, definitions and explanations of building materials
- (from the Greek. thixis touch and trope turn change), the ability of dispersed systems to restore the original structure destroyed by mechanical stress. Thixotropy is an important technological property of flushing fluids used in ... Big Encyclopedic Dictionary
Noun., Number of synonyms: 1 thixotropy (1) ASIS Synonym Dictionary. V.N. Trishin. 2013 ... Synonym dictionary
The ability (property) of some jellies and gels (gelatin, agar, agar, iron hydroxide) under mechanical action (shaking, stirring) to liquefy and turn into sols, which in a calm state again gell. These… … Geological encyclopedia
thixotropy- The phenomenon of a reversible process of transition of jellies and gels into a liquid state under mechanical action Topics oil and gas industry EN thixotropy ... Technical translator's guide
thixotropy- - the ability to spontaneously restore the structuring of gel-like systems after their mechanical destruction. General chemistry: textbook / A. V. Zholnin ... Chemical terms
- (from the Greek thíxis touch and tropē turn, change), the ability of dispersed systems to restore the original structure destroyed by mechanical stress. Thixotropy is an important technological property of flushing fluids used ... encyclopedic Dictionary
thixotropy- Thixotropy Thixotropy Reversible change in the physical and mechanical properties of polymer and dispersed systems under mechanical action under isothermal conditions. For liquid media, it manifests itself in a decrease in viscosity during flow and its gradual ... ... Explanatory English-Russian Dictionary of Nanotechnology. - M.
It is necessary to transfer the contents of the article Thixotropic liquid to this article and put a redirect from there. You can help the project by merging articles (see merging instructions). If necessary, discuss the feasibility ... ... Wikipedia