Contact angle refers to the tangent line of the gas-liquid interface made at the intersection of gas, liquid and solid, and the tangent angle θ between the tangent line and the solid-liquid junction line on the liquid side, and the contact angle measurement is the main method of surface performance testing today.
The standard contact angle measuring instrument is based on the principle of optical imaging, which measures the surface contact angle, wetting performance, surface tension, surface energy and other properties of the sample surface through image profile analysis.
Contact angle measuring instrument is widely used in various industries, in mobile phone manufacturing, glass manufacturing, surface treatment, material research, chemical industry, semiconductor manufacturing, paint and ink, electronic circuits, textile fibers, medical biology and other fields, contact angle measurement has become an important instrument to evaluate surface properties. (Some test functions need to be completed by purchasing special accessories)
1. The wetting behavior of the liquid on the solid surface, such as spreading, penetration, and absorption, is measured by the droplet method
2. Measurement of the advance 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 absorbing materials, and analysis of contact angle curves with time
4. Contact angle measurement of various special materials, such as powders, curved surfaces, superhydrophobic/superhydrophilic samples
5. Attachment drop method test: Contact angle test of material immersed in liquid
6. The hanging drop method measures the surface interfacial tension and polarity and dispersion components of various liquids
7. Calculation of surface free energy of solids, and analysis of polar dispersion components
8. Analyze the adhesion of liquid on solid surface, evaluate the uniformity and cleanliness of solid surface

As shown in the figure above, the contact angle measuring instrument is mainly composed of five parts: light source, injection unit, sample stage, acquisition system and analysis software, and the equipment adopts the principle of optical imaging
The light source adopts dense LED cold light design, which emits uniform light, image cleaning and long life
The injection unit adopts a micro-manual knob type liquid feeding, which is stable and has high precision
The sample stage adopts a three-dimensional manual fine adjustment platform, which is flexible in operation and accurate in positioning, and the sample stage can be customized according to the actual sample size
The acquisition system adopts black and white imported CCD camera, shooting stability, clear image, real and reliable, the lens adopts German industrial-grade imported configuration, 0.7-4.5 times magnification adjustable, and the imaging is deformed without deformation
The analysis software is powerful, with one-click automatic fitting ability, and has international advanced fitting methods to meet the accurate fitting of various drop morphologies
GB/T 24368-2009 (Detection of hydrophobic contaminants on glass surface)
SY/T5153-2007 (Method for determining the wettability of reservoir rocks)
ASTM D 724-99(2003) (Test Method for Surface Wettability of Paper)
ASTM D5946-2004 (Measurement of Contact Angle of Plastic Film with Water)
ISO15989 (Measurement of water contact angle of plastic film and sheet corona treatment film)