RU2362141C2 - Method of determining amount of fluid moved by surfactant - Google Patents

Abstract

FIELD: nanotechnologies.

SUBSTANCE: invention relates to procedures that allow estimating surface properties of materials and can be used in development of power nanotechnologies. The proposed method consists in that a drop of surfactant solution is applied on known-thickness layer for the maximum radius of fluid displacement to be recorded with the help of video- or picture camera. The maximum radius of displace fluid layer and initially known fluid layer thickness are used to determine fluid layer volume displaced by surfactant. Fluid volume and density are used to determine amount of fluid displaced by surfactant.

EFFECT: chances of determining amount of fluid displaced by surfactant.

19 dwg

Description

The invention relates to the field of assessing the surface properties of materials and can be used to develop energy nanotechnology.

There are several methods for determining the surface activity of substances, the most common among which are two methods of determination: by the contact angle of wetting and surface tension. The main characteristics of the surface activity of substances are subsequently used to calculate adsorption, adsorption work, surface activity, etc. These parameters judge the ability of substances to emulsify, suspend or form foams, and the ability of substances to lower surface tension is used to judge their surface activity. By the value of the wetting angle, they judge the hydrophilicity or hydrophobicity of the surface on which it is determined, and use it to determine the wetting ability of liquids and solutions of various substances (see Surface phenomena and surfactants: Reference / A.A. Abramzon, L. E. Bobrova, L.P. Zaichenko and others, under the editorship of A.A. Abramzon and E.D. Shchukin, - L., Chemistry, 1984, p. 392, ill. P. 165) (1 )

The most common way to determine the surface tension by the method of tearing the ring is to "... determine the force necessary to tear off the liquid that moistened the ring from the surface of the liquid. When the ring is opened, the neck of the liquid is pulled out, and after the ring is separated, droplets of the lower phase should remain on it around the entire perimeter. ”(See. Surface phenomena and surfactants: Reference book / A.A. Abramzon, L.E. Bobrova, L. P. Zaichenko et al., Edited by A.A. Abramzon and E.D. Shchukin, - L., Chemistry, 1984, p. 392, ill. P. 167).

The method for determining the wetting angle is carried out "... directly along the droplet profile using a microscope equipped with a goniometer, or a drop is photographed." (See. Surface phenomena and surfactants: Reference book / A.A. Abramzon, L.E. Bobrova, L.P. Zaichenko et al., Edited by A.A. Abramzon and E.D. Shchukin, -L., Chemistry, 1984, p. 392, ill. P. 174).

However, both the wetting angle and surface tension under certain conditions do not give a sufficiently complete characterization of solutions by surface activity due to the impossibility of determining them or the small variability of the indicator being determined from various conditions, for example, the concentration of substances, temperature, the use of substances that are inactive or change surface activity, etc. .d. And increasing the accuracy of determining, for example, surface tension requires increased purity of the material under study (see Surface phenomena and surface-active substances: Reference book / A.A. Abramzon, L.E. Bobrova, L.P. Zaichenko and others, ed. A.A. Abramzon and E. D. Shchukin, - L., Chemistry, 1984, p. 392, ill. P. 164).

In addition, to determine the work of adsorption, wetting, or spreading, it is necessary to know other parameters, the determination of which is associated with significant difficulties or cannot be determined due to the lack of reliable methods of determination.

The introduction of surface-active substances (surfactants) into a liquid changes the surface tension by no more than an order of magnitude, and the contact angle from 0 to 180 °, therefore, it is practically impossible to separate or identify a surfactant.

The technical task of the invention is the development of a method that allows using captured video or film frames to track the action of the studied solution, its ability to move liquid.

The technical result of the invention is to establish the amount of fluid transported by a solution of a surface-active substance (surfactant) with a known concentration and to determine several characteristics of a surfactant not previously used.

The amount of fluid transferred by a solution of a surfactant drop is expressed by the mass of the displaced fluid per unit mass of the investigated surfactant.

The technical result is achieved by the fact that in the method for determining the amount of fluid transported by a surfactant according to the invention, the amount of fluid transported is determined by the volume of a fluid layer of known thickness moved by a drop of a solution of surfactant on the surface of a physical body, the mass of fluid is found by volume and density, fixing the largest radius of the layer of displaced fluid by a video camera or movie camera. A distinctive feature of the proposed method is that it simultaneously determines several characteristics of surfactants that have not previously been used for this purpose. An important point is that the result of the determination is noticeable visually. On successively captured frames, the effect of the studied solution is clearly visible - its ability to move the liquid.

A distinctive feature of the proposed method is also that the amount of transported fluid is determined by the volume of a fluid layer of known thickness, the mass of fluid is found by volume and density, fixing the largest radius of the layer of fluid transferred by a video or movie camera. Since in this case the largest amount of liquid will be moved.

This allows you to directly (without calculation) to determine the work of moving various liquids and solutions on the test surface and express it as the work produced by the unit mass of the test substance. This value, possibly, will be constant under certain conditions for a specific surfactant and may serve as an individual characteristic of substances of various nature. From this value, one can judge the ability of various substances and their solutions to do work, i.e. about their surface activity.

At the same time, one can judge the adsorption capacity of a liquid or materials dissolved in it on the surface under study and evaluate the hydrophilicity or hydrophobicity of ions or parts of molecules of various nature, both solutions and the surface on which the movement is studied, and the liquid in which the surfactant is dissolved. In addition, it is possible to determine the spreading rate of liquids and solutions of various substances on the surface in the regime of replacing a liquid phase with a gaseous one.

Thus, a new set of techniques set forth in the claims of a method for determining the amount of fluid transported by a surfactant, provides a technical result, which consists in establishing the amount of fluid transported by a solution of a surface-active substance (surfactant) with a known concentration and obtain new characteristics of the surface -active substances: the specific amount of fluid transferred and the specific work performed by a surfactant when moving the fluid.

Comparison of the proposed method with other well-known technical solutions from the prior art for patent documentation and scientific and technical literature has allowed us to establish that the authors have not identified solutions that include a combination of features similar or equivalent to the claimed distinctive features set forth in the claims, which allows us to conclude that the proposed invention the criteria of "novelty" and "inventive step".

The proposed method for determining the amount of fluid transported by surface-active substances is illustrated by drawings, where:

figure 1 shows the beginning of the movement of the liquid with a drop of a surfactant solution;

figure 2 shows the completion of the movement of the liquid and the formation of the largest radius of the displaced layer;

figure 3 shows the completion of the reverse process of closing the freed up when moving the area;

figure 4 shows the changes on the surface of the liquid from exposure to a pure solvent (water);

figure 5 shows the definition of the largest radius of the displaced layer for example 1 description;

in Fig.6 shows the definition of the largest radius of the displaced layer for example 2 descriptions;

Fig. 7 shows the determination of the largest radius of the displaced layer for example 3 of the description;

on Fig depicts the definition of the largest radius of the displaced layer for example 4 descriptions;

Fig. 9 shows the determination of the largest radius of the displaced layer for example 5 of the description;

figure 10 shows the definition of the largest radius of the displaced layer for example 6 of the description;

on Fig depicts the definition of the largest radius of the displaced layer for example 7 descriptions;

on Fig depicts the definition of the largest radius of the displaced layer for example 8 descriptions;

on Fig depicts the definition of the largest radius of the displaced layer for example 9 descriptions;

on Fig depicts the definition of the largest radius of the displaced layer for example 10 descriptions;

on Fig depicts a change in the specific work performed by one liter of ethyl alcohol when moving water, depending on its content in the solution;

in Fig.16 depicts a change in the specific amount of transported liquid depending on the content of ethyl alcohol in the solution;

on Fig shows the dependence of the specific amount of fluid transferred from the concentration of sulfonol;

on Fig depicts the change in specific work when moving water with a surface-active substance (surfactant) "Equalizer" depending on the content of the surfactant and the diameter of the bounding circle (liquid layer thickness 0.5 mm);

in Fig.19 shows the change in the specific amount of transported water by the surfactant "Equalizer" depending on the content of the surfactant and the bounding circle (liquid layer thickness 0.5 mm).

The proposed method for determining the amount of fluid transported by a surfactant is as follows.

On a table with an adjustable level of horizontal surface lay a plate of material, the surface properties of which must be investigated. To hold a liquid layer, for example, 0.1-1 mm thick, on the surface under study, a circle of a hydrophobic substance is applied to the material, if the liquid is polar, or of a hydrophilic substance, if the liquid or solutions of various substances whose influence is to be studied are non-polar. Then, a video camera or movie camera is installed so that the boundary line and the center of the bounding figure are clearly visible in the viewfinder and, if possible, occupy the entire frame area (adjusting image sharpness). After adjusting the sharpness of the image, a ruler with a division price of 1 mm is installed and fixed with a camera for subsequent scaling of measurements. The line is set perpendicular to the optical axis of the lens fixing the process of the camera exactly in diameter. Then the line is removed.

The test liquid is introduced into the circle bounded by a hydrophilic or hydrophobic substance in an amount necessary to create a liquid layer of a thickness selected by the researcher.

A pipette tip calibrated by the mass of the droplet and the diameter of the capillary is set exactly above the center of the bounding figure, such as a circle, so that the drop from it drops as accurately as possible to the center of the figure. The edge of the pipette tip is set at a height of 4-30 mm. A scattered-light illuminator with dark lines deposited on its luminous surface in the form of a grid or with a grid of opaque material installed on it (luminous surface) or a grid deposited on a transparent material is set so that the image of the grid reflected from the surface of the investigated liquid in the fixing chamber was clearly visible.

The camera is turned on to capture the image, at the same time to determine the droplet volume at the moment of separation from the capillary, the pipettes include a camera that fixes the droplet on an enlarged scale, and a drop of a surfactant solution or the test liquid is introduced into the center of the circle. The frames of the film that recorded the process of moving the fluid are sequentially studied, determining the distance from the center of incidence of the droplet to the base of the "displacement wave", and, in accordance with the scale, are converted to length units. And determine the diameter of the drop at the time of separation from the capillary of the pipette.

If it is necessary to determine or compare the properties of surfactants, you can use the "standard" surface, which can be used as a hydrophobic heat-resistant film, or writing paper, or paper with a modified surface, such as gelatin.

When working with paper, a circle is applied to it with the necessary inner diameter from a hydrophobic paint, for example a tar solution. The line width of the bounding figure is 5-6 mm. The paper with the restrictive figure applied to it is soaked in a solvent, for example in water, for a certain time, for example 10 minutes, and placed on a table or a plane-parallel plate (thick glass) laid on it. In this case, the paper is straightened and air is removed from under it by extrusion using a glass tube with rounded ends, for example a pipette with a diameter of 10-15 mm, or another device, such as a roller for rolling photos for glossing. On the paper area limited by the drawn lines (circle, square), the test liquid is applied in the amount necessary to create a layer with a thickness determined by the conditions of the experiment. A pipette tip is installed in the center, locking chambers are turned on, and a drop of the test surfactant solution is introduced into the center of the restrictive figure.

The method is illustrated by the following images in the drawings. After touching a drop of a surfactant solution (see Fig. 1), a small "funnel" forms on the surface of the liquid layer. From it in different directions begins to propagate the "wave of movement" of the liquid, which reaches after a while the maximum movement (see figure 2). Then the freed part of the surface is closed with a liquid (see figure 3). The indicated images (see Figs. 1-3) show the process of moving a liquid with a surface-active substance called “Equalizer”, with a concentration of 5 g / dm ³ . Accordingly, for figures 1, 2, 3, frames 5, 16, 77 of the movie. The inner diameter of the bounding circle is 122 mm. The thickness of the water layer is 0.5 mm. For comparison, figure 4 shows the change on the surface of the water from the fall of a drop of pure water.

Examples confirming the specific implementation of the method for determining the amount of fluid transported by a surfactant.

Example 1. A paper with a circular boundary line drawn on it is soaked in distilled water and placed on a level table, removing air from under the paper by rolling a glass tube with melted ends. The fixing device - the video camera is sharpened by the image of the center of the figure. Then set the ruler in the center of the circle and fix the camcorder. Inside the restriction ring, water is added in an amount providing a layer thickness of 0.5 mm. The inner diameter of the circlip is 122 mm. Set a pipette with a known drop volume above the center of the restrictive ring and add a drop of surfactant solution from a height of 7 mm. A surfactant solution is a preparation (used in the leather and fur industries) “Leveling agent” with a concentration of 5 g / dm ³ . After viewing each frame of the video, the largest radius of the displaced layer of water is determined (see FIG. 5), which is 24.427 mm.

The area of the displaced layer is 3.14 * (24.427) ² = 18.74613 cm ² . The volume of displaced water is 18.74613 * 0.5 = 0.937306 cm ³ or 0.937306 g. The drop contained a surfactant of 3.15E-05 g. Then the specific amount of displaced water will be 29778.58 kg of water per kilogram of surfactant, and produced one kg surfactant work will amount to 7133.545 joules.

Example 2. Preparatory operations are carried out analogously to example 1. The thickness of the water layer is 0.5 mm. The inner diameter of the circlip is 144 mm. Surfactant solution - “Equalizer” 3 g / dm ³ . The surface is paper. After viewing each frame of the movie, the largest radius of the displaced layer of water is determined (see Fig. 6), which is 26.54 mm.

The area of the extruded layer is 3.14 * (26.54) ² = 22.12849 cm ² . The volume of displaced water is 2212.849 * 0.5 = 1.106424 cm ³ or 1.106424 g. The drop contained a surfactant of 1.99E-05 g. Then the specific amount of displaced water will be 55625.21 kg of water per kg of surfactant, work - 14477 , 49 joules.

Example 3. Preparatory operations are carried out analogously to example 1. The thickness of the water layer is 0.5 mm. The inner diameter of the circlip is 102 mm. The surfactant solution is “Equalizer” 0.25 g / DM ³ . The surface is paper. After the storyboard of the video film, the largest radius of the displaced layer of water is determined (see Fig. 7), which is equal to 14.69 mm. The area of the extruded layer is 3.14 * (14.69) ² = 6.779434 cm ² . The volume of displaced water is 0.338972 cm ³ or 0.3389717 g. The drop contained a surfactant of 2.91E-06 g. Then the specific amount of displaced water will be 116490.5 kg of water per kg of surfactant. Work performed - 16781.58 joules.

Example 4. Preparatory operations are performed analogously to example 1. The thickness of the water layer is 0.5 mm. The inner diameter of the restrictive ring is 164 mm. The surfactant solution is ethyl alcohol (96%) 8 cm ³ / dm ³ . The surface is paper. After the storyboard of the video film, the largest radius of the displaced layer is determined (see Fig. 8), which is 11.97284 mm. The area of the displaced layer is 3.14 * (1.197284) ² = 4.503438 cm ² . The volume of water transferred 4.503438 * 0.5 = 0.225172 cm ³ or 0.225172 g. The drop contained 96% ethyl alcohol 6.6E-06 cm ³ . Then the specific amount of displaced water will be 34138.14 kg of water with one dm ^{3 of} ethyl alcohol, and the work performed - 4008.277 joules.

Example 5. Preparatory operations are performed analogously to example 1. The thickness of the water layer of 0.6 mm The size of the bounding square frame is 160 * 160 mm. The surfactant solution - "Sulfonol" 100 g / DM ³ . The surface is paper. After the storyboard of the video film, the largest diameter of the displaced layer of water is determined (see Fig. 9), which is 56 mm. The area of the displaced layer is 3.14 * (5.6 / 2) ² = 24.63009 cm ² . The volume of displaced water is 24.63009 * 0.6 = 1.477805 cm ³ or 1.477805 g.

Example 6. Preparatory operations are performed analogously to example 1. The thickness of the water layer of 0.6 mm The size of the bounding square frame is 160 * 160 mm. The surfactant solution - "Sulfonol" 100 g / DM ³ . The surface is gelatin. After the storyboard of the video film, the largest diameter of the displaced layer of water is determined (see Fig. 10), which is 55.5 mm. The area of the displaced layer is 3.14 * (5.55 / 2) ² = 24.19223 cm ² . The volume of displaced water 24.19223 * 0.6 = 1.451534 cm ³ or 1.451534 g.

Example 7. Preparatory operations are performed analogously to example 1. The thickness of the water layer is 0.4 mm The size of the bounding square frame is 160 * 160 mm. The surfactant solution - "Sulfonol" 100 g / DM ³ . The surface is gelatin. After the storyboard of the video film, the largest diameter of the displaced layer is determined (see Fig. 11), which is 73.5 mm. The area of the displaced layer is 3.14 * (73.5 / 2) ² = 42.42917 cm ² . The volume of displaced water is 42.42917 * 0.4 = 1.697167 cm ³ or 1.697167 g.

Example 8. Preparatory operations are performed analogously to example 1. The thickness of the water layer is 0.1 mm. The size of the bounding square frame is 140 * 140 mm. The surfactant solution - "Sulfonol" 100 g / DM ³ . The surface is paper. Drop height 15 mm. After the video storyboard, the largest diameter of the displaced layer is determined (see FIG. 12), which is 89.5 mm. The area of the displaced layer is 3.14 * (89.5 / 2) ² = 62.91236 cm ² . Water volume 62.91236 * 0.01 = 0.629124 cm ³ or 0.629124 g.

Example 9. Preparatory operations are carried out analogously to example 1. The thickness of the water layer is 1.0 mm. The size of the bounding square frame is 140 * 140 mm. The surfactant solution - "Sulfonol" 100 g / DM ³ . The surface is paper. After the storyboard of the video film, the largest diameter of the displaced layer is determined (see Fig. 13), which is 55.5 mm. The area of the displaced layer is 3.14 * (55.5 / 2) ² = 24.19223 cm ² . The volume of water is 24.19223 * 0.1 = 2.419223 cm ³ or 2.419223 g.

Example 10. Preparatory operations are performed analogously to example 1. The thickness of the water layer is 0.5 mm. The inner diameter of the restrictive ring is 164 mm. Surfactant solution - Laundry soap 5 g / dm ³ . The surface is paper. Drop height 30 mm. After the video storyboard, the largest diameter of the displaced layer of water is determined (see Fig. 14), which is 55.9 mm. The area of the displaced layer is 3.14 * (55.9 / 2) ² = 24.5422 cm ² . The volume of water is 24.5422 * 0.05 = 1.22711 cm ³ or 1.22711 g.

It can be seen from the above examples that surfactants can move fluid under different experimental conditions, and the resulting characteristics of the amount of fluid transferred and the specific amount of fluid transferred can serve as a measure of surface activity. At the same time, it should be noted that the energy component of nanotechnology of the process of moving fluid can be up to 100,000 or more joules per 1 kg of surfactant.

Using the proposed method for determining the amount of fluid displaced by a surfactant, the authors determined a new indicator for surfactants - the specific amount of fluid transferred and the specific work performed by the surfactant when moving the fluid. In addition, the authors revealed a new regularity - the maximum amount of fluid transported and the work performed in this case, depending on the concentration of surfactants (see Fig.15-19).

As can be seen from the drawings, the specific amount of fluid transferred and the specific work performed by the surfactant in all cases have a maximum. The maximum occurs at different concentrations of surfactants in solution. The maximum value is different. So for ethyl alcohol, the maximum specific amount of liquid transported by one liter of alcohol is 5470.93 kg, and the maximum specific work is 885.8025 j / kg (see Fig. 15, 16). The onset of the maxima corresponds to the content of 7 ml of 96% alcohol in one liter of water. The maximum specific amount of water transported by one kg of Sulfonol surfactant is 1894.87 kg and accounts for a concentration of 1 g / dm ³ (Fig. 17).

On Fig, 19 shows the results of a study of the movement of water with the drug "Equalizer". From Fig. 18 it is seen that the maximum specific work is accounted for by the surfactant concentration of 0.5 g / dm ^3, and with an increase in the radius of the bounding circle, its value increases, respectively, for radii 4.1; 5.1; 6.1; 7.2; 8.2 cm maximum is 24310.54; 37675.31; 55,213.11; 80001.27; 108148 j. This is two orders of magnitude less than the calorific value of coal, which is 21-34 * 10 ⁶ j. Similarly, the maximum of the amount of fluid transferred changes accordingly, the maximum is 139196.3; 186410; 240,506.1; 307,961.1; 376510.4 kg of displaced water with one kg of surfactant. The values of the considered indicators have a wide range of changes for different surfactants. In the examples given, the values of the maxima of the specific work vary from 885.8025 j / kg for ethyl alcohol to 108148 j for the “Vyrivnatel” preparation. And the maximum of the specific amount of liquid transferred varies from 1894.87 for the Sulfonol surfactant to 376510.4 kg of transported water with one kg of the Equalizer surfactant. This may serve as a prerequisite for the classification of surfactants according to these criteria.

Therefore, the above experimental results allow us to conclude that the claimed invention meets the criterion of "industrial applicability".

Claims (1)

A method for determining the amount of fluid transported by a surfactant, characterized in that a drop of a surfactant solution is added to the surface of a fluid layer of known thickness, the largest radius of the transferred fluid is recorded by a video or movie camera, by the largest radius of the transferred fluid layer and the initially known layer thickness liquids determine the volume of a layer of liquid transported by a surface-active substance, and the mass and quantity of liquids are determined by the volume and density of a liquid and transported by a surfactant.

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