METHOD AND SYSTEM FOR MEASURING THE INTERFACIAL TENSION BETWEEN TWO FLUIDS Russian patent published in 2021 - IPC G01N13/02 G01N33/28 

FIELD: physical chemistry.

SUBSTANCE: invention relates to methods for measuring interfacial tension between two fluids. In accordance with the proposed method for measuring interfacial tension between two fluids, an X-ray transparent heat-resistant cell connected to a device for forming a drop of the second fluid by means of a hollow needle located in the cell is filled with the first fluid, X-ray imaging of the cell filled with the first fluid is carried out and the result of the survey is stored as a background image. Then, at least once, a drop of the second fluid is created inside the first fluid in the cell at the end of the needle by pumping the second fluid from the fluid drop forming device. During the time sufficient to achieve the equilibrium value of the interfacial tension, X-ray imaging of the cell with the first fluid and with the droplets of the second fluid created at the end of the needle is continuously carried out, droplets remaining stationary during the time of image capture are detected, and contrasting images are obtained for stationary droplets by joint processing of the background image and images of the cell with the first fluid and with the droplets of the second fluid created in it. For the contrasted images, the parameters of the capillary pressure equation are searched, including the values of the interfacial tension, which correspond to the shape of the drop, leading to a spatial distribution of intensities as in the contrasted image, and the time dependence of the interfacial tension value between the first and second fluid is obtained. The system for measuring the interfacial tension between two fluids in accordance with the present invention contains an X-ray transparent heat-resistant cell placed in an X-ray imaging device and made with the possibility of filling with the first fluid, and a device for forming a drop of the second fluid inside the first fluid, connected to the cell by means of a hollow needle located inside the cell to form a drop of the second fluid inside the cell, and the needle is located inside the cell so that the needle is at least partially visible on the resulting X-ray image. The system also contains a module for obtaining a contrasting image of a drop, the input which receives images taken by the X-ray imaging device, while the module is designed to determine the immobility of the droplet during the time of image capture, and the module to search for parameters of the capillary pressure equation, the input of which is connected to the output of the module for obtaining a contrasting image of the droplet, while the module is designed to obtain a time dependence of the value of the interfacial tension between the first and second fluid.

EFFECT: providing the possibility of measuring the time dependence of the value of the interfacial tension between two fluids, regardless of the optical transparency of the fluids under study.

14 cl, 7 dwg