CS230207B1 - Microscopic goniometer for measuring angles of wetting solid substanges with liquids - Google Patents

Description

(54) Microscopic goniometer for measuring liquid wetting angles

The goniometer is designed to measure liquid wetting angles.

The essence of the apparatus consists of a special stand on which a microscope with a calibrated and crosshair is mounted, the measuring chamber having a reservoir of test liquid and placed on a workbench angle.

The device can be used in engineering, textile, paper, leather and cotton industries to assess the quality of adhesives to various materials.

The invention relates to a microscopic goniometer for measurement. wetting angles of a solid. The wetting angle of the solid is used to calculate the equilibrium work of adhesion according to:

Wa = / LVo (1 + CoS Θ), where Θ is the 'wetting angle' measured by the goniometer, / lvo is the surface tension of the test liquid in its saturated vapor environment.

The principle of measuring the wetting angle on a microscopic goniometer is to determine it from an enlarged image of a liquid droplet, wherein ¹ is the wetting angle defined by the surface of the solid and tangent to the liquid droplet. The disadvantage of the devices used for. measuring the wetting angle is. difficulty, respectively. impossibility to measure dynamic increasing. a. decreasing wetting angles.

The above-mentioned drawbacks are eliminated by an apparatus which is based on the fact that the binocular tube is fitted with a rotatably mounted 180 ° calibrated eyepiece with an inserted movable crosshair and the measuring chamber is spring-fastened to angles which are screwed to the rotating round table formed by a scale of up to 360 °, wherein the movable eyelet of the measuring eyepiece is formed on a planar parallel plate movably inserted into the optical assembly of the eyepiece so as to permit simultaneous focusing of the movable eyelet and the stable crosshair of the binocular tube. with a test liquid reservoir and a stainless steel suffix with a solid sample and a top with courtyard glazed circular visors fixed with brass rings.

The advantage of the microscopic goniometer for measuring solids wetting wetting solids is that it is simple, high accuracy, and reproducible to measure dynamic increasing and decreasing wetting angles by rotating the scale-formed circle to which the measurement is attached. chamber, about the horizontal axis.

The invention is schematically illustrated in the drawings, wherein FIG. 1 is a microscopic goniometer; FIG. 2. measuring eyepiece, fig. 3 shows a pickling chamber, FIG. 4 shows a diagram of a measuring chamber with a test fluid reservoir, and FIG. . 5 graphically illustrates the principle of measuring the wetting angle on a miciroscopic goniometer.

Static optical system 1. The microscopic goniometer is brought into the horizontal position by the stabilizing screws 5 a. The measuring eyepiece 4 calibrated to 180 ° is located on the superstructure 11 of the binocular tube 10 with a stable nickel cross and is supplemented by an inserted movable crosshair 12. The measuring chamber 3 is attached by means of aluminum angles 9 to the rotating ring 2 with the scale formed 360 °. By means of the sliding screws 14, the edge of the drop 20 in the measuring chamber 3 is moved to the center of the crosshair 12. The measuring chamber 3 with the test liquid reservoir 17 at the bottom allows measurement in an environment of saturated test liquid pairs. A solid sample 15 is placed on a stainless steel plate 16 to divide the field of view of the microscope goniometer lens 18 into two equal halves. The measuring chamber 3 is provided on both sides with glazed observation windows 18 fixed with brass rings 19.

The measurement procedure on a microscopic goniometer is as follows:

The measuring eyepiece 4 is brought to the home position by adjusting the zero angle of wetting 21 on the measuring scale. eyepiece. 4 'against the reading line 13 and overlapping the movable crosshair 12 of the measuring eyepiece 4. with a stable crosshair. binocular. . tubusa 10. The soaking angle '21 is determined by tangent to the 'arm' of the movable crosshairs 12 to the edges of the drop 20. testovacej. liquid.

The microscopic goniometer according to the invention can be used in various industries. industry (machinery, textile, paper, leather and fiber) to assess the quality of adhesives to various materials.

Claims (3)

SUBJECT A microscopic goniometer for measuring the liquid wetting angles of a solid consisting of a microscope with a horizontally mounted static optical system and a stable crosshair embedded in a binocular tube and with a rotating circular table, characterized in that it is rotatable on the body (11) of the binocular tube (10). a built-in measuring eyepiece (4) calibrated to 180 ° with an embedded movable crosshair (12) formed, and the measuring chamber (3) is fixed by a spring to the bracket (9) which is screwed to the rotary table (2) with scale up to 360 °. Microscopic goniometer for measuring the liquid wetting angles of a solid according to claim 1, characterized in that the movement of the inventive reticle (12) of the measuring eyepiece (4) is formed on a planar parallel plate movably inserted into the optical system of the measuring eyepiece (4). to allow simultaneous focusing of the movable reticle (12) and the stable reticle of the binocular tube (10). 3. Microscopic goniometer for measuring the liquid wetting angles of a solid according to claim 1, characterized in that the measuring chamber (3) consists of a lower part with a test liquid reservoir (17) and a stainless steel holder (16) with a sample (15). ) of solid material and at the top with two glazed circular visors (18) fixed with brass rings (19).