What Are Contact Angle Measurements?
Contact angle measurements are used for studying and measuring the wetting properties of liquid on a surface. A small droplet of the liquid is placed on the surface and images of the droplet are acquired with a high-speed camera at up to 3000 frames per sec. The software analyzes the drop shape and contact angles in real time without operator intervention. Integrated topography measurements allow for roughness-corrected contact angle measurements.
These measurements characterize how hydrophobic or hydrophilic a surface is. They characterize liquid repellency of self-cleaning surfaces, such as coated glass, and they give information on wetting states of micro-textured surfaces that exhibit large apparent contact angles. By measuring dynamic contact angles and contact angle hysteresis, the quality of coatings and applied films can be inferred. By using several standard liquids with different properties (such as water, ethylene glycol, and diiodomethane), the surface free energy can be determined, providing a quantitative measure of wetting properties.
Contact angle measurements are ideal for:
- Characterizing surface pretreatments
- Investigating the adhesion and stability of bonds and coatings
- Testing plastic, glass, ceramics, paper, wood or metal wettability
- Characterizing wafer and microelectronics quality
- Surface cleanliness investigations
Surface Free Energy
The surface energy is an important measure when analyzing the wettability of a surface or how well a surface repels a liquid. The surface energy of the material will be changed by the chemistry of a coating or adhesive applied during treatment.
Wettability of the surface is important in processes such as painting and printing and has been utilized in the study of cells to biomaterial interactions. Examples of materials we have tested with this method include:
- Contact lenses
- Implants and stents
- Wood-plastic composites
- Polymers and coatings
In powder compounding, understanding the wettability of a solid material helps with the development and quality control of a wide variety of industries, from concrete to pharmaceutics. The coatings applied to powders are designed to improve wettability to disperse the powder into a liquid. Knowing the wettability of a powdered or dry component has a significant influence on the dissolution rates which influences interactions with other particles during formulation and manufacturing and determine batch cycle time.
We provide data you need to understand and improve your formulation and process control parameters. We provide the behavior and stability of suspensions, emulsions, froth and foams. Examples of coated powders and application support:
- Powder and pigments
- Powder coatings for hydrophilic and hydrophobic surfaces
- Food additives
- Optimizing the manufacturing process of pharmaceutical granules
- Paper recycling process optimization
- Powdered stone, silica sand or carbon black as additives in plastics