Contact Angle

Contact angle, θ, is a quantitative measure of the wetting of a solid by a liquid. It is defined geometrically as the angle formed by a liquid at the three phase boundary where a liquid, gas and solid intersect. If the angle θ is less than 90° the liquid is said to wet the solid, with a contact angle of zero representing complete wetting. If it is greater than 90° it is said to be non-wetting. Both static and dynamic contact angles can be used to gain additional information, for example, to characterize surface heterogeneity and roughness with the use of contact angle hysteresis. This is defined as the difference between the maximum and minimum contact angle values obtained by advancing and receding values, respectively.

Typical industrial uses

Paint and Printing 

  • Wetting behaviour
  • Surface tension studies
  • Wetting envelope diagrams

Aerospace and Automotive

  • Surface contamination indication
  • Direct wettability studies
  • Adhesive bonding

Hydrophobic surfaces

  • Release agents and films
  • Non-stick applications
  • Self-cleaning surfaces

Polymer Processing

  • Quantitative surface free energy measurements
  • Effects and aging of surface pre-treatments, e.g. plasma, flame, corona 

Paper and Textures

  • Adsorption

Key Capabilities

  • Sessile drop method
  • Surface free energy determination of solids
  • Advanced and receded drop measurements
  • Pendant drop method for surface and interfacial tension
  • Lamella contour analysis
  • Curved baseline determination for convex and concave surfaces

 

LMCC currently has a Dataphysics Optical Contact Angle OCA 20 device, details of which can be obtained below:

Built-in detectors:

  • CCD video capture (768 x 576) and up to 50 images per second
  • Standard reference liquids used: water and diiodomethane
  • Motor-driven and software-controlled syringe dosing units
  • High-temperature controlled chamber TEC400
  • High-temperature needle, NHD 400

Are you interested in using this technique?

If you are interested in using this technique and would like further information please do not hesitate to get in touch.

Loughborough Researchers Industrial Users / External Researchers