Powder Wetting Angle Measuring InstrumentIt is a key instrument used to evaluate the surface wettability of powder materials, and its principle and measurement method are as follows:

1、 Core principle

　　Powder Wetting Angle Measuring InstrumentIt is the angle formed when the liquid comes into contact with the surface of the powder, reflecting the wetting ability of the liquid on the powder:

Small contact angle: The liquid is easy to spread and the powder has strong hydrophilicity.

Large contact angle: The liquid is difficult to spread and the powder has strong hydrophobicity.

The instrument captures the morphology of liquid droplets on the surface of the powder, combines image processing technology to calculate the contact angle, and then analyzes the surface properties of the powder (such as hydrophilicity and hydrophobicity).

2、 Measurement method

Compression method

Step: Press the powder into a flat sheet, and use a contact angle measuring instrument (such as the seat drop method) to directly measure the contact angle of the liquid droplet on the sheet.

Applicable scenarios: After powder compression, the surface is smooth and the hydrophilicity is moderate.

Limitations: If the surface of the powder after compression is rough or strongly hydrophobic, it may cause measurement errors.

Penetration method (Washburn method)

Steps:

Load the powder into a hollow tube with uniform inner diameter (such as a quartz tube) and compact it to form a powder column.

Immerse the lower end of the tube into a liquid with a known surface tension, and the liquid will rise due to capillary action.

Record the changes in liquid rise height or weight over time, and calculate the contact angle using the Washburn equation.

Applicable scenarios: Hydrophilic powders (such as metal oxides, ceramic powders).

Limitations: Not applicable to hydrophobic powders such as carbon powder and certain organic powders, as liquids are difficult to penetrate.

Dynamic infiltration method

Improvement: Capturing the process of liquid infiltration through a high-speed camera and analyzing real-time changes in contact angle, suitable for studying powder wetting kinetics.