SU1543298A1 - Device for measuring contact angle of wetting of porous and pulverulent materials - Google Patents

Abstract

The invention relates to instrumentation technology, namely, devices for determining the wetting angle of liquid porous materials, and can be used in the study of physicochemical properties at the interface. The aim of the invention is to increase the information content by providing an express determination of the boundary angles of leakage, outflow and equilibrium wetting angle. To this end, one of the parallel plates is mounted on a spring parallelogram with the possibility of horizontal movement, and the other on a horizontal spherical spring-loaded support. 1 il.

Description

The invention relates to instrumentation engineering, in particular, to devices for determining the wetting angle of solid materials, including porous and powder, and can be used in various parts of the national economy in determining the physicochemical properties at the interface.

The aim of the invention is to enhance the functionality of the device by providing an express determination of the boundary angles of flow, the casting and the equilibrium wetting angle.

Pa the drawing shows a diagram of the device for determining the wetting angle.

The device comprises a housing 1, insulated from the external environment by a cover 2 of optically transparent material, plates 3 and 4 of the test material installed in it, between which there is a liquid 5. The plates 3 and 4 are installed with a variable gap a vertically. The plate 4 is fixed rigidly in the spring parallelogram 6, which allows you to smoothly change the gap between the plates 3 and 4 in the measurement process, providing a precise parallel

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nosti plates between themselves. Plate 3 is mounted on a horizontal spherical spring-loaded support 7, placed in the saddle 8.

The test fluid 5 is also located in the lifting cuvette 9 below the plates 4 and 3, which ensures the natural filling of the gap between them by infiltration under the action of capillary forces. The cuvette 9 is provided with a screw 10 for moving it in a vertical direction, and the spring parallelogram 6 with a screw 1 1 for moving it horizontally.

The shape of the meniscus of the fluid in the gap between the plates 3 and 4 is recorded using an optical acquisition system.

The service works as follows.

The plates 3 and 4 of the material under study are mounted on a horizontal spherical spring-loaded support 7 and spring parallelogram 6. A horizontal spherical spring-loaded support 7 allows plate 3 to take any position relative to the saddle 8. Spring parallelogram allows plate 4 to move parallel to the initial position and thereby changing the clearance a. The screw 11 moves the spring parallelogram 6 with the plate 4 until it touches the plate 3, and then until the latter comes off together with the horizontal spherical spring-loaded support 7 from the saddle 8. At the same time, it is possible to choose the non-parallelness of the plates 3 and 4 due to the spring of the spherical support 7. the screw 11 in the opposite direction, the plate 4 together with the plate 3 is retracted until the latter touches together with the horizontal spherical spring-loaded support 7 of the saddle 8, and then until the gap is restored to 20-40% less than the average size of the pores or particles, which consists of the material under study. Plate 3 along with horizontal spherical

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The spring-loaded support 7 occupies a stable position in the saddle 8, while ensuring the parallelism of the plates 3 and 4 during the measurements. After the gap has been restored, the cuvette 9 is raised with a screw 10 until the liquid 5 contacts the plates. The liquid under the action of capillary forces begins to fill the gap.

In the process of lifting the fluid, the optical system is combined with the meniscus of the fluid in the gap between the plates 3 and 4, the profile of the fluid meniscus is measured, from which the radius of curvature of the meniscus is measured and the contact angle is calculated.

After the cessation of the visible rise of the liquid (almost to a decrease in the rate of ascent to 1 mm / min), which is achieved in 5-10 minutes, the gap increases from, to 7 7 by 30-50%. The meniscus fluid begins to descend. In the process of lowering the fluid, the radius of curvature of the meniscus is measured and the marginal flow angle is calculated.

The equilibrium wetting angle is determined by the radius of curvature of the meniscus after the liquid has descended.

Claims (1)

Invention Formula A device for determining the wetting angle of porous and powder materials, comprising a vessel for a liquid in which two parallel flat plates of the material under study are located, characterized in that, in order to expand the functionality of the device by providing an express determination of the edge angles of leakage, draining and equilibrium edge the wetting angle, one of the plates is mounted on the spring parallelogram with the possibility of horizontal movement, and the other on the horizontal with of spherical sprung support. I 6 ten Editor I.Rybchenko Compiled by A. Koscheev Tehred M. Khodanych Proofreader O. Tsiple Order 396 Circulation 484 VNIIPI State Committee for Inventions and Discoveries at the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35, Raushsk nab. 4/5 Production and Publishing Combine Patent, Uzhgorod, st. Gagarin, 101 Subscription