Term: Contact Angle

Category: Chemistry

Definition: Contact angles are used as a numerical quantifier for how wettable a material is (how readily conformable a liquid is to a given solid). A low contact angle (<90°) indicates that a material is hydrophilic (wettable), whereas a high contact angle (>90°) indicates a material that does not readily accept a liquid (i.e., forms a droplet). The contact angle of a material depends on its surface characteristics (e.g., surface energy, roughness, and chemical composition), as well as the liquid’s interfacial/interactions with the solid. Contact angle control is vital in many applications of biomaterials and coatings, including adhesion, lubrication, and biocompatibility.

Common Uses: 

• Assessing the hydrophilicity or hydrophobicity of medical device surfaces
• Optimizing adhesion of coatings, adhesives, and paints
• Evaluating surface treatments like plasma, chemical etching, or hydrophilic coatings
• Designing biomaterials, implants, and hydrogels for improved tissue interaction and fluid handling

Related Content and Resources: 

Hydromer® Hydrophilic Coatings 

Wettability and Uniform Moisture Distribution in Medical Coatings