Surface tension measurement - analysis by Goniometer
Your need: perform a Goniometer analysis
The Goniometer in a few words
The goniometer is a device for measuring surface tension and surface tension by contact angle.
The device deposits a drop of deionised water or other solvent with a predefined volume of a few µl on the surface of a material and then analysis the shape of the drop at a rate of 80 images per second.
Why perform a Goniometer analysis?
The dimensions of the droplet give information on the intermolecular forces and allow the calculation of a surface tension in mN/m.
The angle formed between the droplet and the material gives information on the hydrophilic character of the material studied. The smaller the angle measured, the more hydrophilic the material.
For certain applications such as gluing or printing, the absorption rate of a liquid on its substrate is a critical parameter.
The dynamic measurement of the contact angle provides information on the spreading rate or absorption rate of the material under analysis. As with the static measurement, a drop is deposited on the surface of the material. The evolution of its contact angle is measured by acquiring an image every millisecond for up to 10 minutes.
FILAB offers you its Goniometer analysis services
In order to support manufacturers in the development and quality control of their products, the FILAB laboratory provides a state-of-the-art 2100m² analytical facility for goniometer analysis.
This equipment can be used in addition to other analytical techniques:
our services
Drop size measurement by laser granulometry
Surface energy measurement
Drop angle measurement
Measurement of adhesion between a liquid and a solid
Characterization of droplet distribution by SEM-FEG-EDX
Measurement of the surface wettability of a material
Liquid surface tension measurement
Static and dynamic drop angle measurements
FAQ
Contact Angle is the most widespread method for quantifying the wetting properties of a solid and characterizing other surface features. The contact angle is defined as the angle formed by a liquid droplet at the point where the three phases (solid, liquid, and gas) converge, also known as the three-phase boundary point. At this boundary, there is an equilibrium between the forces exerted on it by the solid, liquid, and gas or sometimes by the solid, liquid, and liquid. Generally, a measured contact angle below 90° indicates high wetting properties, while a contact angle above 90° indicates low wetting properties.
Surface tension can be understood in two ways: as a tension force acting along all directions of the surface per unit length, or as the energy needed to increase the surface area. In both interpretations, the surface aims to minimize its surface area or potential energy. Consequently, a surface with no (or negligible) external forces will take the form of a sphere, which has the smallest surface area to volume ratio.
A goniometer is an instrument used to measure the surface tension of a liquid via contact angle methods. A droplet (e.g. water or another solvent) is deposited on a material's surface, and the contact angle between the droplet and the surface is measured—either statically or dynamically. The geometry of the droplet shape also gives information about the liquid’s surface tension in units such as mN/m.
- Static contact angle: the angle of a single droplet left to equilibrate on the surface; gives a snapshot of wettability.
- Dynamic contact angle: the change in angle over time (e.g. advancing/dropping or receding), which reflects how fast a surface absorbs or spreads a liquid. Useful for understanding adhesion, printing, or coating behaviors.
Goniometer-based surface tension measurement is relevant for:
- coatings, paints, and printable materials (adhesion, spreading)
- cosmetics (formulations with solvents or surfactants)
- materials science (material wettability, hydrophilic/hydrophobic surfaces)
- pharmaceutical, biomedical, or packaging industries where surface behavior influences performance.
Commonly, deionised water is used as a probe liquid. Other solvents or liquids may also be used depending on the sample and the properties to be characterised (e.g. surfactant solutions, organic solvents). The choice of liquid can impact the measured contact angle and thus interpretation.
Surface tension is typically expressed in milliNewtons per meter (mN/m) or equivalently dynes per centimeter (dyn/cm).
Contact angles are reported in degrees (°).
- State-of-the-art equipment, enabling static and dynamic contact angle measurements with fine temporal resolution.
- Skilled technical staff, within a 5,200 m² facility with full analytical park.
- Accredited laboratory (ISO 17025), ensuring quality, reliability and traceability of analyses.
- Tailored support: from quoting to interpreting results, with flexible options depending on the sample and objective.
