Contact angle measurements

Purpose

Contact angle measurements is a fast and relatively simple method for studying the interaction between a liquid and solid, and it demands little sample preparation. The method is extremely surface sensitive and is well suited for evaluation of the cleanability of a surface. Other common application areas are studies of the hydrophilicity or hydrophobicity of a coating, or adhesion of a substance to a surface. The method can be used for determining the absorption velocity of a liquid in a porous material, which for instance can be of importance in printing.

Contact angle measurements are also commonly used for calculation of the surface energy of a solid, a property which otherwise is difficult to measure. This is done by determining the contact angle of a series of liquids with known properties, and the surface energy is calculated using a mathematical formula. The method can also give information about the polar and non-polar contribution of the surface energy. The surface energy of a material gives useful information for instance about the adhesion of a coating, paint or ink to the surface, or how well a surface withstands dirt.

Method

The contour of a liquid droplet is analyzed optically at high resolution. The automated dispensing unit allows exact dosing of the liquid. Our instrument also enables tilting of the substrate, which allows determination of the roll-off or sliding angle, i.e. the tilt angle of the substrate when the droplet rolls or slides off a surface.

Our instrument can also create very small droplets (picoliter), which enables contact angle measurements on very small sample sizes, for instance single fibers. The instrument is also equipped with a high-speed camera which allows studies of dynamic wetting phenomena.

Deliveries

The results are delivered according to agreed terms.