What is an optical contact angle testing instrument?

The contact angle refers to the tangent line at the intersection of gas, liquid, and solid at the interface between gas and liquid. This tangent line has an angle between the liquid and solid-liquid boundaries. The measurement of contact angle is currently the main method for surface performance testing. The standard contact angle measuring instrument uses optical imaging principles and image contour analysis to measure surface contact angle, wettability, surface tension, surface energy, and other properties. The equipment has high cost-effectiveness, comprehensive functions, and can meet the needs of conventional measurement. It has been widely used in many universities, research institutes, and manufacturing enterprises.

Nowadays, contact angle measuring instruments are widely used in various industries, such as mobile phone manufacturing, glass manufacturing, surface treatment, semiconductor manufacturing, coatings and inks, 3C electronic manufacturing, textile fibers, medical biology and other fields. Contact angle measurement has become an important instrument for evaluating surface performance.

The general operation process of the water droplet angle tester is as follows. Let's learn and explore its operation process and the factors that need to be considered in the measurement method process together:

1.The wetting behavior of liquids on solid surfaces, such as diffusion, permeation, and absorption, is measured by the droplet method to determine the static contact angle;

2. Measure the forward angle, backward angle, contact angle hysteresis, rolling angle, and dynamic contact angle of the material on the solid surface;

3. Continuous real-time research and process recording of absorbent materials, as well as curve analysis of contact angle changes over time:

4. Measure the contact angle of various special materials, such as powders, curved surfaces, superhydrophobic/superhydrophilic samples;

5. Test the contact angle of materials immersed in liquid using the adhesive droplet method;

6. Measure the interfacial tension, polarity, and dispersion composition of various liquid surfaces using the droplet method;

7. Calculate the surface free energy and analyze its polar dispersion composition;

8. Analyze the adhesion of liquids on solid surfaces to evaluate the uniformity and cleanliness of the solid surface.

After normal testing with a droplet angle measuring instrument, significant changes will occur. Analysis includes measuring the angle at which the droplet contacts the surface. The contact angle range starts from 180 degrees when the surface is completely wetted. In the case of water on the surface, a contact angle less than 90 degrees indicates that the surface is hydrophilic at 90 degrees, indicating that the surface is hydrophobic.

Water droplet angle measuring instruments are commonly used to quantify the surface properties of unknown materials by measuring the wettability of the surface using various test liquids, or by applying known liquids to the material,

There is an instrument that can detect the numerical value after cleaning, spraying, and coating. It can reflect the uniformity, roughness, and cleaning effect of surface treatment. It is the magical droplet angle measuring instrument. Currently, the measurement method will comprehensively consider the following factors:

1. Droplet volume: Droplet volume that is too large or too small can affect the accuracy of droplet angle measurement. Generally speaking, for common solid surfaces, a droplet volume between 2-10 μ L is more suitable. Multiple measurements can be taken by changing the droplet volume to observe the change in droplet angle. If the measurement value is stable within the appropriate volume range, it indicates that the measurement result is reliable.

2. Measurement time: After the water droplet comes into contact with the sample surface, its shape may change over time, especially for some wettable surfaces. Therefore, measurements should be taken as soon as the water droplet reaches equilibrium with the surface, usually within 10-30 seconds after the water droplet is placed. At the same time, the optimal measurement time can be determined by continuously observing the curve of the water droplet angle over time.

3. Measurement angle: When measuring the angle of a water droplet, it should be ensured that the measurement angle of the instrument is consistent with the actual contact angle plane of the water droplet. Multi angle measurement methods can be used, such as measuring from different angles such as front and side. If the measured values from different angles are not significantly different, it indicates that the measurement results are more accurate.

In summary, there are some common knowledge about water droplet angle measuring instruments. If you need to learn about fully automatic or semi-automatic water droplet angle measuring instruments, you can privately chat with the friends of Zhenyi Co., Ltd. Thank you for your attention!