Sigma force tensiometers are widely used in research, development and quality control for the determination of:
- Surface tension
- Interfacial tension
- Critical micelle concentration
- Powder wettability
- Dynamic contact angles
- Surface free energy
- Surface heterogeneity
Force tensiometry is a powerful and accurate technique to measure static surface tension and interfacial tension of liquids. These direct measurements allow determination of a number of material and surface properties, such as dynamic contact angle, surface free energy, critical micelle concentration and wettability. This information can also be used to determine adhesion, absorption, adsorption, cleanliness, surface heterogeneity, density, spreading, porosity, powder or sedimentation wettability, material solubility, biocompatibility and lubricity of solid surfaces, to name but a few.
Force tensiometry has become the method of choice for many industrial standards related to characterization of liquids. It is also the most widely used technique for measuring critical micelle concentration of surfactants. In addition, it is the only method to determine the absorption and contact angle of a packed powder or of fiber beds using the Washburn method. Whatever your research objectives, there is a Sigma instrument to meet your needs.
Measurement principle: When a solid touches the surface of a liquid, the liquid tends to be drawn up in a meniscus. The force exerted by the meniscus is measured and analyzed to determine surface tension. Using high surface free energy probes such as a platinum Du Noüy ring or Wilhelmy plate allow precise measurement of these forces. All Sigma tensiometers measure surface and interfacial tension using push and pull modes by ring. Correction calculations of surface and interfacial tension are made using models from Huh and Mason (Harkins and Jordan, Zuidema & Waters and others also available).
Following standards are available for force tensiometers
||Standard test methods for surface and interfacial tension of solutions of surface active agents
||Standard test method for interfacial tension of oil against water by the ring method
||Plastics/rubber -polymer dispersions and rubber latices - Determination of surface tension by
the ring method
||OECD Guideline for the testing of chemicals - surface tension of aqueous solutions
||Surface active agents. Determination of interfacial tension of solutions of surface active agents
by the stirrup or ring method
||Surface active agents - Determination of surface tension