Surface tension and surface area viscosity measuring device

Abstract

The invention discloses a surface tension and surface area viscosity measuring device. Before gas is introduced into a gas bottle, an open container rises. After a capillary absorbs a proper amount of a liquid sample, the open container descends. Then gas is introduced into the capillary from the gas bottle to form a bubble in the capillary. A camera or video camera is provided to record the forming process of a bubble and the shape images of the bubble so as to measure the radius of the bubble. A differential pressure meter is arranged on the outside of a testing box and is communicated with the gas which is introduced into the capillary, so the differential pressure meter can read the pressure difference between the inner and outer of the bubble. Then the surface pressure can be calculated through the Laplace formula, and thus the calculation of surface tension is greatly simplified. The surface area viscosity can be calculated by the following steps: measuring the surface tension during the unbalance state and balance state, recording the time, calculating the surface area according to the images, and finally substituting the data into a formula to calculate the surface area viscosity. The device has the following advantages that the sample using amount is little, the moisture of the sample is not required, the measuring speed is fast, the precision is high, and the equipment utilization rate is high.

Description

technical field [0001] The invention relates to a device for physical and chemical properties of a liquid, in particular to a device for the physical properties of the liquid interface and the internal physical properties of an object, and is applied in the fields of metallurgical physical chemistry, colloid chemistry, materials, medicine, biology and the like. Background technique [0002] Surface tension provides people with first-hand information on the interaction between gas-liquid and liquid-liquid. It is one of the basic physical and chemical properties of liquid systems. Important parameters. In medicine, it is one of the basic measurement data in the experimental research of prevention and treatment of acute respiratory distress syndrome; surface tension is related to molecular size and force, and is an important parameter reflecting the characteristics of non-uniform fluids, and is also the basis of multiphase system research And the starting point; In metallurgy ...

AI Technical Summary

Problems solved by technology

[0008]Limitation of scope of application: the capillary material must be a transparent solid material, such as glass, etc.; the measured liquid does not react with the transparent capillary material; The material of the container in which the liquid is placed does not react;

[0013]Limitation of the scope of use: Harkins and Jordan considered the case where the contact angle is zero when making the correction coefficient table, and the non-zero contact angle will affect the accuracy of the obtained results It cannot be used for the measurement of surface tension in various atmospheres and the measurement of high-pressure surface tension; Zettle-moyer et al. pointed out that this method cannot obtain accurate and repeatable results for surfactant solutions, and the relative error can be as high as 10%.

[0018]Limitation of the scope of use: the liquid must wet the sheet well and keep the contact angle at zero; it is not suitable for the determination of high temperature, high pressure and dark color liquid; it cannot be used for Determination of high pressure surface tension;

[0022] The measurement accuracy of this measurement method mainly has the following factors: the measurement accuracy of the radius of the capillary; The balance of the liquid drop surface will be disturbed, changing the temperature of the liquid surface, and affecting the measurement accuracy; the maximum pressure difference in this method is the difference between the atmospheric pressure and the system pressure, so when the air flow in the room is flowing, it will cause changes in the atmospheric pressure, making the experimental measurement There is a certain error in the obtained data; the smoothness of the end surface of the inserted capillary and the wettability of the melt and other interface effects have a great impact on the formation of test bubbles, and the measurement data produces errors.

[0023]Limitations of scope of use: the measured liquid does not react with the capillary; it cannot be used to study the surface tension that is slow to reach equilibrium

[0028]Limitation of scope of application: it cannot be used to measure the surface tension that reaches equilibrium slowly, and at the same time, this method cannot achieve complete equilibrium; it cannot be measured quickly

Limitations of the range of use: dealing with systems with negative shape factor β

[0032] Static drop method: This measurement method has the following characteristics: the equipment is complicated, the operation is troublesome; the data processing is also complicated

The following factors affect the measurement accuracy of this measurement method: the choice of substrate material; when measuring the interfacial tension, an X-ray perspective device is required to take pictures of the shape of the metal droplet in the slag, due to the limited X-ray perspective ability, etc. , so that the shape of the metal droplet is blurred compared with the photo taken by ordinary optics, thus increasing the error of the shape of the metal droplet

Limitations in the scope of application: dealing with interfaces with positive shape factor β limits the scope of application

[0033]The earliest recorded method for measuring surface tension was in 1851. Simon proposed the maximum bubble pressure method, which has been developed for more than 160 years. However, even the above six methods that are relatively mature have various limitations, so it is necessary to develop new measurement methods

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