CN115386340B - Discontinuous shear thickening fluid and preparation method and application thereof - Google Patents

Abstract

The invention discloses a discontinuous shear thickening fluid, a preparation method and application thereof. The discontinuous shear thickening fluid comprises dispersed phase particles calcined kaolin, dispersion medium water or glycol, and the preparation method comprises weighing and mixing; calcined kaolin is used in discontinuous shear thickening fluid dispersed phases. The discontinuous shear thickening fluid disclosed by the invention has the advantages of low initial viscosity, easy flow when inclined, obvious shear thickening effect when stimulated and capability of realizing the shear rate of 100S ^‑1 Rapid thickening within, individually even as low as 10S ^‑1 The liquid-solid conversion behavior of millisecond response can be realized under a certain shear rate, and the flow can be quickly recovered to self-level after the stimulation is finished. The formula of the invention has the advantages of simple formula, convenient manufacture, long-term stability, low cost and the like, and can greatly solve the problem of poor coordination of various indexes of the traditional shear thickening fluid.

Description

Discontinuous shear thickening fluid and preparation method and application thereof

Technical Field

The invention belongs to discontinuous shear thickening fluid, and particularly relates to discontinuous shear thickening fluid, and a preparation method and application thereof.

Background

Shear thickening fluids (Shear Thickening Fluid, STF) are non-newtonian fluids, also known as dilatant fluids, which undergo a sharp rise in viscosity under high shear, and return to a free-flowing state rapidly after shear has disappeared. Discontinuous shear thickening fluids (Discontinuous Shear Thickening Fluid, DSTF) can be categorized as shear thickening fluids, but their performance is significantly better, and when the shear rate reaches a certain value, the viscosity can transition significantly, even with a liquid-solid conversion behavior of millisecond response. The shear thickening fluid has reversible property and special thickening property, so that the shear thickening fluid has wide application prospect in the fields of sports buffer equipment, puncture-proof fabrics, liquid bulletproof clothes, damping vibration dampers, shear thickening gel and the like, and the core technology of the application depends on the excellent performance of STF, so that the development and research of high-performance STF such as DSTF become important content in the field.

The conventional STF disperse phase particles mainly comprise nano-SiO ₂ 、SiO ₂ 、SiC、Al ₂ O ₃ 、B ₄ C、TiO ₂ 、ZnO、CaCO ₃ And PMMA, PS, HPA, wherein the dispersion medium mainly comprises water, ethylene Glycol (EG), polyethylene glycol (PEG), mineral oil and the like, and the materials have a shear thickening effect according to a certain rule combination, but most of liquid-solid conversion characteristics are not outstanding. Shear thickening was first discovered in 1938 and scientists in U.S. N.J. Wagner et al, 80, studied nano-SiO first ₂ A shear thickening system prepared by dispersing particles in PEG. Wang Lun etc. by synthesizing rod-like mesoporous SiO ₂ The STF is mixed with PEG to generate STF, a shear-oscillation thickening mechanism is constructed based on rod-shaped particles, a steady-state rheological curve of a sample shows that the STF has an initial shear viscosity value which is too large, the viscosity curve increases with the shear rate, decreases and then increases and tends to be stable, the stable viscosity value is lower than an initial value, the STF has poor self-flowing performance, the viscosity at a high speed is lower than static, and rod-shaped mesoporous SiO is synthesized ₂ The complexity and viscosity characteristics of (c) are detrimental to its development and application. Fu Yaqin and the like are mixed into a system by preparing four needle-shaped ZnO whiskers and PEG, and SiO is added ₂ The micro-nano sphere obtains a novel STF, the viscosity curve increases along with the shear rate, slowly decreases and then increases to the peak value and then decreases, and the viscosity curve is only formed by ZnO and SiO ₂ The descending section is not measured when the concentration is high, the descending process after the peak value appears indicates that the viscosity of the product is limited in ascending amplitude, and meanwhile, the preparation process generally needs a plurality of processes such as dissolution, stirring, suction filtration, drying, degassing and the like, which takes more than 20 hours and is unfavorable for development and application. Wu Sizhu et al produced STF using inorganic nanoparticles, boric acid, hydroxy silicone oil and plasticizer, and provided a molecular colloid-based STF preparation method. In general, the present stage is directed to nano-SiO ₂ PE of (2)G or EG systems are more studied, and the problems of low utilization rate of nano materials, unobtrusive liquid-solid conversion characteristics, higher difficulty in the preparation process, high price and the like exist. The choice of superior DSTF materials is very limited, where the most representative system is generally only the water starch (CS) system, and the organic nature of the starch polysaccharide results in poor stability under conditions of high temperature, long-term placement, etc., and product development is limited. Based on the reasons that the main performance index of the disclosed material is not outstanding, the compatibility of related performance is poor, the variety of the high-performance long-term stable material is deficient, the preparation process is complex and the like, the product development in the field is greatly limited.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a discontinuous shear thickening fluid, a preparation method and application thereof.

The aim of the invention is achieved by the following technical scheme:

use of calcined kaolin in a discontinuous shear thickening fluid dispersed phase.

A discontinuous shear thickening fluid comprising dispersed phase particles of calcined kaolin.

Further, it contains a dispersion medium.

Further, the dispersion medium is water or ethylene glycol.

Further, the weight ratio of the dispersion medium to the calcined kaolin is 100:80-120.

A method of preparing a discontinuous shear thickening fluid comprising the steps of:

s1, weighing: weighing calcined kaolin and a dispersion medium according to the formula proportion;

s2, mixing: adding calcined kaolin into the dispersion medium step by step, stirring and mixing uniformly by adopting manual or mechanical stirring, wherein the stirring speed is lower than 60r/min, and the stirring time is lower than 10min.

The calcined kaolin is obtained by calcining kaolin at high temperature to lose structural water, the silicon oxide layer basically maintains the original tetrahedral layered structure characteristic, the coordination number (four coordination) of silicon is not changed, and the order degree is reduced; the aluminum oxide layer is converted from a hexacoordinated octahedral layer of aluminum into a form in which four, five and six coordination of aluminum coexist, and the ordering degree is poor. The kaolin fragments formed after calcination consist of a silicon oxygen tetrahedral layer with higher order degree and an aluminum oxide layer with poorer order degree. Particle scanning electron micrographs of calcined kaolin and uncalcined kaolin show particle morphology that is similar but essentially two different species with significant differences in chemical properties.

The calcined kaolin is uncharged because of no lattice substitution of the raw ore, and oxygen atoms on the upper surface and the lower surface of the lamellar structure can form solvated films with water or glycol through hydrogen bonds (O: H: O). Experimental research shows that the calcined kaolin has the characteristics of submicron size, lamellar structure, higher strength, small diameter-thickness ratio, good grading, no charge, weak hydration film and the like, and the fluid is a 'surface-surface superposition structure' which reduces potential energy and is easy to form compact and flat. The structural feature can diffuse positive stress, shear stress and other direction acting forces in a high-speed state in a large stress diffusion angle mode, so that the contact resistance perpendicular to the sheet-shaped structural surface and the friction resistance parallel to the sheet-shaped structural surface cooperatively provide a strong resistance effect, and the liquid-solid conversion behavior of millisecond response is reflected. The solution of preparing DSTF by calcined kaolin and water or EG can realize flow to reach self-leveling at high consistency, and is helpful for shear thickening and even obvious liquid-solid conversion behavior.

The invention has the following advantages: the invention discloses the use of calcined kaolin as discontinuous shear thickening fluid disperse phase particles, and discloses a discontinuous shear thickening fluid which has low initial viscosity, is easy to flow when inclined and has obvious shear thickening effect when stimulated, and can realize the shear rate of 100S ^-1 Rapid thickening within, individually even as low as 10S ^-1 The liquid-solid conversion behavior of millisecond response can be realized under a certain shear rate, and the flow can be quickly recovered to self-level after the stimulation is finished. The invention has the advantages of simple formula, convenient manufacture, long-term stability, low cost and the like, and can greatly solve the problem of poor coordination of various indexes of the traditional shear thickening fluid.

Drawings

Fig. 1 is a SEM photograph of kaolin before calcination (left column) versus after calcination (right column).

FIG. 2 is a graph of the water swelling curves of kaolin before and after calcination.

FIG. 3 is a plot of viscosity change of a slurry of water and calcined kaolin.

FIG. 4 is a photograph of the morphology of a slurry prepared from water and calcined kaolin at a ratio of 1:1.2.

FIG. 5 is a graph showing the viscosity change of a slurry prepared from ethylene glycol and calcined kaolin.

FIG. 6 is a photograph of morphology of a slurry prepared from ethylene glycol and calcined kaolin at a ratio of 1:1.2.

Fig. 7 is a schematic representation of the structure of kaolin before (left) and after (right) calcination.

FIG. 8 is a schematic diagram showing the effect of positive (left) and shear (right) stresses in a fluid.

Detailed Description

The invention will be further described with reference to the accompanying drawings and examples, to which the scope of the invention is not limited:

the invention aims to develop a DSTF with obvious shear thickening effect, particularly obvious liquid-solid conversion characteristic under the condition of keeping the initial viscosity of slurry low, namely inclined and easy to flow and quick self-leveling after being stimulated, can realize liquid-solid conversion behavior under the condition of lower shear rate, and has the advantages of simple formula, long-term stability, low cost and the like.

The invention is not limited to the prior theoretical frame, breaks through the traditional requirements of dispersed phase particles on sphere, rod-shaped, needle-shaped particle morphology, nano-scale particle size and the like, aims to find a novel DSTF scheme in a platy structural substance, experimentally screens silicate minerals with platy structures such as kaolin, chlorite, illite, montmorillonite, rectorite, attapulgite, sepiolite, calcined serpentine, calcined kaolin and the like, only the calcined kaolin shows the advantage characteristics of DSTF, tests the change rule of viscosity along with the shear rate through a rotational viscometer, photographs the macroscopic morphology characteristics of slurry in a container, such as standing, flowing and being matched with a glass rod in the stress states such as impact, stirring, drawing and the like, and finds that the shear thickening is obvious and the liquid-solid conversion characteristics are outstanding. Meanwhile, through SEM scanning electron microscope imaging, microscopic mechanism analysis and water absorption expansion experiment on calcined kaolin, and compared with uncalcined kaolin without DSTF characteristics, shear thickening mechanism analysis and stress response stress analysis are carried out.

1. Experimental equipment

(1) Experimental facilities: an intelligent digital display twelve-speed rotary viscometer ZNN-D12S, a Zeiss GeminiSEM 360, a four-in-one intelligent dilatometer CTP and a press MK-PM10.

(2) Experimental reagent: calcined kaolin and non-calcined kaolin of the same brand (i.e., water-washed kaolin prior to calcination)

2. Experimental method

The following tests were performed, and microstructure analysis, shear thickening mechanism analysis, stress response stress analysis were performed on the basis of the experimental results. Both water and ethylene glycol react with calcined kaolin due to the hydroxyl (-OH) groups, so only water and calcined kaolin interact with each other for various analyses.

(1) Electron microscope test: characterizing structural characteristics of particles before and after kaolin calcination by a scanning electron microscope;

(2) Expansion test: the round cake samples with the same mass before and after the kaolin calcination are pressed, and the hydration capacity difference of the round cake samples is tested by adopting an dilatometer.

(3) Viscosity test: preparing slurry with different concentrations by using water or glycol and calcined kaolin respectively, testing the viscosity change rule of the slurry in the transition process from low speed to high speed, and shooting macroscopic morphology features of the slurry in a container, such as standing, flowing and matching with a glass rod in stress states of impact, stirring, drawing and the like;

3. experimental results

Electron microscope test

The dry powder samples before and after the same brand of kaolin is calcined are selected, and the amplification factors of 5000, 10000, 20000 and 50000 are imaged by using a Zeiss GeminiSEM 360 under the acceleration voltage of 5.0KV, and the imaging is specifically shown in figure 1.

Experimental results summary: 1. the particle morphology of the kaolin is not greatly changed before and after calcination, and the kaolin has submicron-level flaky structure characteristics (the thickness is about 50nm, and the diameter is about 100nm to 1000 nm) with good grading; 2. the kaolin is calcined to increase the dispersion degree, and the color is visually observed to change from gray to white; 3. the calcined kaolin has a aspect ratio in the range of less than about 20.

Expansion test

10g of each of uncalcined kaolin and calcined kaolin is weighed, a cake sample is prepared by using an MK-PM10 press under the same pressure of 4MPa for 5min, the prepared sample heights are 17.1mm and 22.3mm respectively, the cake sample is put into a four-in intelligent dilatometer CTP clear water for soaking, the change condition within 6h is tested, the final linear expansion amount is 1.73mm and 1.18mm respectively, and expansion curves before and after kaolin calcination are drawn as shown in figure 2. Wherein: linear expansion ratio=Δh/h ₀ *100%, Δh is the cake increase height, h ₀ Is the initial height of the wafer.

Experimental results summary: 1. the linear expansion curves of the uncalcined kaolin and the calcined kaolin are fast raised and are fast stable, and the maximum values of 10.06% and 5.29% are respectively reached at 1h40min and 47min10s, which indicates that the water absorption stability time is shorter and the water absorption expansion is lower after the kaolin is calcined; 2. the calcined kaolin with the same quality has higher sample preparation height than the uncalcined kaolin, which indicates that the particle dispersion degree is increased after calcination, the inner surface area of the prepared round cake sample is larger, more hydration films are supposed to be formed, but the actual linear expansion amount (rate) is low, which indicates that the hydration capacity is reduced after the calcination, so that the hydration films are weakened and thinned.

Viscosity test-Water and calcined Kaolin

The slurry with different concentrations is prepared by water and calcined kaolin, the viscosity of the slurry is tested in a mode of gradually increasing the rotating speed by 1r/min, 2r/min and 3r/min … … r/min, the instrument is set to record once per second, the display data tend to be stable as much as possible, but the data stability time is different or can not be stable under each step under the influence of the concentration of the slurry, the data quantity is different, and the experiment is ended when the test range of the instrument is exceeded. The relative concentration ratios and the recorded data amounts are shown in Table 1. The uncalcined kaolin has no obvious shear thickening effect through initial test, and no comparative experiment is carried out.

TABLE 1 viscosity test related concentration ratios and recorded data volumes

Remarks: data with x indicates that the instrument test range was exceeded and the recorded values were the maximum value of instrument capacity 1216.7.

Unifying the number of plotted data facilitates plotting the rheological profile as shown in fig. 3. Data screening was performed under the following principles, with data representative conditions ensured: 1. all values beyond the instrument test range are shown as values 1216.7, namely, the shearing force value is 1216.7 ×0.511= 621.73Pa, and the actual shearing force is not actually measured, so the data with the number is deleted and not shown in the curve, but the representative meaning is shown in table 2; 2. under the same speed ladder, deleting other concentration data by taking the small number of data as a standard; 3. when the instrument is just started, the slurry is incompletely attached to the instrument, and initial data with large fluctuation at 1r/min are deleted; 4. the same data of the part (not all) which is stable under a certain speed ladder is deleted preferentially, and redundant data is deleted at equal intervals, so that a curve can be drawn from final stable data, and the fluctuation of the data can be reflected to the greatest extent.

Table 2 represents viscosity characteristics over instrument test range data

The morphology photographs of the slurry prepared by providing water and calcining kaolin in a ratio of 1:1.2 and the glass rod under different stress states of standing, flowing, shearing, pulling and the like are shown in fig. 4.

Experimental results summary: 1. the viscosity of the fluid is slowly reduced to rapidly increased along with the increase of the speed ladder, and the fluid is basically consistent with the rheological behavior of classical shear thickening fluid; 2. at the same speed, the larger the concentration of the slurry is, the larger the viscosity is; 3. except for the fact that an instrument is just started at 1r/min, the higher the speed gradient, the larger the fluctuation range of the viscosity of the slurry is, even the fluctuation is back and forth, and the stability cannot be kept in a normal state; 4. the higher the concentration of the slurry is, the more obvious the viscosity trend is along with the increase of the speed gradient, and the slurry has obvious discontinuous thickening characteristics and obvious liquid-solid conversion; 5. the larger the data point variation amplitude of the same speed ladder in the curve is, the larger the viscosity fluctuation range is, the smaller the viscosity fluctuation range is, and the stability is easy.

Viscosity test-ethylene glycol and calcined kaolin

The method and the principle of data screening are the same as those described above, the rheological curve is shown in figure 5, the viscosity characteristics of data exceeding the test range of the instrument are shown in table 3, and the morphology photographs of different stress states of the slurry prepared by the glycol and the calcined kaolin in a ratio of 1:1.2 are shown in figure 6.

Table 3 represents viscosity characteristics over instrument test range data

4. Microstructure analysis

4.1 microstructure of kaolin before and after calcination

The ideal chemical composition of the kaolin is Al ₂ O ₃ .2SiO ₂ .2H ₂ The crystal of O is a 1:1 layer clay mineral composed of a layer of Si-O tetrahedron and a layer of Al (O, OH) octahedron, and the OH of one unit cell and the O of the adjacent unit cell are tightly connected together through hydrogen bonds (O: H: O), so that the non-calcined kaolin layer structure is not easy to separate.

The kaolin loses structural water after calcination, and the structure becomes loose from compact as the calcination temperature increases and the calcination time increases more thoroughly. The silicon oxide layer basically maintains the original tetrahedral layered structure characteristics, the coordination number (four coordination) of silicon is not changed, and the order degree is reduced; the aluminum oxide layer is converted from a hexacoordinated octahedral layer of aluminum into a form in which four, five and six coordination of aluminum coexist, and the ordering degree is poor. The kaolin fragments formed after calcination consist of a higher ordered silicon oxygen tetrahedral layer and a lower ordered aluminum oxide layer, the structure before and after calcination is shown in fig. 7.

4.2 structural Performance differential analysis

(1) Calcination reduces the number of aluminum coordination hydroxyl (-OH) groups of kaolin, obviously weakens the action of hydrogen bonds (O: H: O) between adjacent unit cells, and is easier to separate between layers;

(2) The calcined kaolin silica layer and the aluminum oxide layer are still connected with each other through the original bridge oxygen bond, the silica layer is basically unchanged, so that the clay mineral crystal part characteristics are still reserved, and the sheet structure still has certain strength;

(3) The kaolin has no lattice substitution and no exchangeable interlayer cationic particles, the unit chemical formula charge number is zero, and the colloid formed by mixing the kaolin with water is basically uncharged except that the surface hydroxyl (-OH) ionization and side bond breaking cause a small amount of electric quantity unsaturation. Calcination causes it to lose structural water, but does not change its charging characteristics, and can still be considered to be uncharged;

(4) The upper and lower surfaces of the sheet structure of the uncalcined kaolin always consist of an O atomic layer and an OH atomic layer, wherein the O atomic layer and H ₂ H of O is linked by hydrogen bond to H of hydration membrane ₂ O tends to be O outwards, whereas the OH atomic layer is reversed, hydrating the H of the film ₂ O tends to have H facing outward. Thus, there is a case where there is mutual attraction between the uncalcined kaolin layers;

(5) The upper and lower surfaces of the calcined kaolin sheet structure are basically O atomic layers to form H of upper and lower hydration films ₂ O tends to be outward, making it difficult to attract or even repel between layers. When the high-consistency calcined kaolin slurry is inclined, the flaky structure is easy to flow under the assistance of the mutually exclusive hydration films, and the flaky structure slides microscopically to form a self-leveling effect, and other clay minerals can form a soft plastic paste without the characteristics through tests;

(6) The water is a polar molecule, and the slurry colloid before and after the kaolin is calcined is uncharged, and can form a hydration film through hydrogen bonds, but compared with montmorillonite (especially sodium montmorillonite), the thickness of the hydration film is obviously thinner, the strength of the hydration film is smaller due to smaller hydrogen bond energy, and the hydration film is easy to fall off under the external action, so that the kaolin layer surface is exposed.

(7) The montmorillonite consists of two layers of silicon oxygen tetrahedron and one layer of aluminum oxygen octahedron, and has O atom on the surface of the flaky structure, similar to calcined kaolin in nature, but no shear thickening phenomenon is obvious in initial measurement, and the difference is that the crystal lattice substitution (Al ³⁺ Substituted portion Si ⁴⁺ ，Mg ²⁺ 、Fe ²⁺ Substituted part of Al ³⁺ ) The surface of the lamellar structure can form an electric double layer, the thickness of the hydration film is large, and the particle diameter-thickness ratio is obviously larger;

(8) The calcined kaolin colloid is uncharged, has small mutual repulsive force, microscopic flaky particles are used for reducing potential energy, a 'face-face superposition structure' is easy to form, the montmorillonite colloid has the same negative charge, the faces are easy to repel, a 'clamping house structure' is formed in a line-face mode, and other clay minerals such as chlorite, illite, rectorite and the like have similarity.

5. Analysis of shear thickening mechanism

(1) The theory of the occurrence mechanism of shear thickening reflects the research depth in the field, and four explanations mainly exist at present: 1 ordered-disordered transition theory (ODT); 2. hydrated particle cluster theory (hydro master); 3. occlusion theory (Jamming); 4. contact rheology theory. The prior researches show that the first 3 theories are all studied by taking spherical nano particles with basically same particle size as a model, and generally require that the spheroidization rate is high, the nano-scale (1-100 nm) and the particle size distribution is uniform and concentrated, wang Lun and the like are based on rod-shaped SiO ₂ The shear-oscillation thickening mechanism is constructed, the orientation and agglomeration characteristics are considered, and the thickening explanation of the particle cluster to the rod type is perfected. From the SEM and microstructure analysis of calcined kaolin, the calcined kaolin does not have the above characteristic requirements and cannot be explained and described by the theory;

(2) Through scanning electron microscope, expansion test and microstructure analysis, the calcined kaolin has the characteristics of submicron size, lamellar structure, higher strength, small diameter-thickness ratio, good grading, no charge, weak hydration film and the like, and the submicron size ensures that particles are easy to form colloid with stable suspension; the flaky structure is uncharged and has high strength, so that the flaky structure is easily tiled in a dispersion medium to form a 'face-face superposition structure'; the small diameter-thickness ratio ensures that the surface-to-surface superposition structure is not easy to form large cavities, meanwhile, the gradation is good, the filling of the formed cavities is facilitated, and the compactness is high, so that the quick response can be realized with low displacement change; the thin hydration film can meet the lubrication flow at low shear rate and can self-level; the weak hydration film can be easily damaged under the action of high stress, and the friction contact effect is obviously increased;

(3) The contact rheology theory mentions that the fluid lubrication force is dominant when the normal contact force between particles is smaller under the low shear rate; when the normal contact force between particles is large, the fluid film between the particles is broken, the contact of the particles is increased, the contact force and friction force between the particles play a dominant role, and researches show that the friction contact of the particles is the most main cause for thickening liquid.

(4) The shear thickening needs to have a sufficiently large slurry concentration to increase the particle contact probability, the function is not realized under the condition of low concentration through initial measurement, friction force needs to be required to contact an object to have relative motion or relative motion trend, the friction force is passive force, no independent autonomous direction and size exist, when the shear thickening fluid is subjected to impact, shearing and other active forces, passive force can be instantaneously generated, the passive force can instantaneously disappear after withdrawal, and the liquid-solid resistance behavior and the solid-solid state recovery have a synchronous effect with the loss and regeneration of the hydration film on the surface of the particle lamellar structure.

6. Stress response stress analysis

Calcining kaolin can form a tiled compact "face-to-face overlay structure", now subjected to stress analysis from normal stress (perpendicular to the tile) and shear stress (parallel to the tile), as can be seen in particular in fig. 8.

(1) When positive stress acts, the stress is influenced by the sheet structure to be diffused in a large stress diffusion angle mode, the positive stress is converted into oblique acting forces with different angles in different directions, the component force of the oblique acting force perpendicular to the sheet structure surface enables contact resistance to be generated, and the component force parallel to the sheet structure surface enables friction resistance to be generated, and the two acting together provide strong resistance behavior, as shown in a stress conduction schematic diagram in fig. 8 (left).

(2) The shear stress acts, the front lamellar structure balance is broken to generate congestion, the shear stress is converted into oblique acting forces with different directions and different angles, the oblique acting forces are parallel to component forces of the lamellar structure surface to generate friction resistance, and meanwhile, component forces perpendicular to the lamellar structure surface to generate contact resistance, and the shear stress and the component forces act together to provide strong resistance behavior, as shown in a stress conduction schematic diagram in fig. 8 (right).

(3) The fluid can be decomposed by other forms of acting force in the mode, the contact resistance perpendicular to the sheet structure surface is higher when the acting speed is high, and meanwhile, the friction resistance is higher due to the larger stress perpendicular to the sheet structure surface, and the series of complex strong resisting effects show solid-like properties after the DSTF is stimulated.

7. Conclusion(s)

(1) The experiment shows that the calcined kaolin has chemical and structural characteristics different from those of the traditional shear thickening fluid disperse phase particles, so that the calcined kaolin can be mixed with water (or glycol) to form a special solvation film, a tiled compact surface-surface superposition structure is realized, the flow can reach self-leveling at high consistency, the shear thickening and even the liquid-solid conversion can be facilitated, and the calcined kaolin can be well explained by using a contact rheology theory;

(2) The calcined kaolin slurry fluid can be effectively decomposed by various acting forces, and particularly provides larger contact resistance and friction resistance at a high acting rate, and shows stimulated solid-like properties, wherein the phenomena of ethylene glycol and calcined kaolin are more prominent.

(3) The calcined kaolin has obvious shear thickening effect, the experiment provides new experimental data and a solution idea, the calcined kaolin is stable and is not easy to deteriorate, the calcined kaolin can be used as a DSTF material with better performance for further research and application, and the situation that high-performance novel functional materials such as motion buffering equipment, stab-resistant materials, damping vibration dampers and the like in the current stage are lack can be relieved.

The foregoing is only a preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art who is skilled in the art to which the present invention pertains will appreciate that the technical scheme and the inventive concept according to the present invention are equally substituted or changed within the scope of the present invention.

Claims (2)

1. A discontinuous shear thickening fluid comprising dispersed phase particulate calcined kaolin clay, further comprising a dispersing medium, said dispersing medium being water or ethylene glycol; the weight ratio of the dispersion medium to the calcined kaolin is 100:80-120.

2. A method of preparing a discontinuous shear thickening fluid according to claim 1, comprising the steps of:

s1, weighing: weighing calcined kaolin and a dispersion medium according to the formula proportion;

s2, mixing: adding calcined kaolin into the dispersion medium step by step, stirring and mixing uniformly by adopting manual or mechanical stirring, wherein the stirring speed is lower than 60r/min, and the stirring time is lower than 10min.