contact angle

The contact angle is a measure of how a liquid interacts with a solid surface. It is the angle formed between the edge of the droplet and the surface it’s on. A small contact angle indicates the liquid spreads out or wets the surface well, while a large contact angle shows the liquid beads up and does not wet the surface easily. This measurement helps us understand properties like how well a liquid can clean, paint, or stick to surfaces, and is important in many fields including coatings, manufacturing, and biology.