Dataphysics

The dynamic contact angle measuring devices and tensiometer of the DCAT series are universal measuring devices for the force-based measurement of interfacial parameters and phenomena.

Surface tension acts to contract and minimise any liquid surface. If a surface is being enlarged by the formation of a liquid lamella, as a test body, such as a Wilhelmy plate or Du Noüy ring, is in contact with it, the surface tension exerts a tensile force that can be measured. Within a tensiometer this force is measured by a high precision weighing system and, hence, the surface tension of the liquid can be calculated.

Using a tensiometer, also the interfacial tension between two liquids can be measured with the help of a test body. Since tensiometry is based on force measurements it is – in contrast to the optical analysis of pendant drops – not necessary that one of the liquids is transparent or that the refractive index differs between the two liquids. Therefore, tensiometry is in many cases a handy alternative to the optical measurement of surface and interfacial tensions.

With the humidity generators and controllers of the HGC series the relative humidity can be controlled inside of small measuring chambers. Hence, the influence of humidity on interfacial parameters can be investigated in combination with another measuring device from DataPhysics Instruments.

Humidity is an important parameter for many different material analysis systems. Since the humidity generators and controllers of the HGC series can work stand-alone and are available as OEM products, they can be used for many laboratory applications and devices. For example Verpaalen et al. were able to investigate a bioinspired bilayer actuator that changes its bending angle depending on temperature and humidity using a HGC 30.

The MS MultiScan dispersion stability analysis system is a compact and versatile measuring device for the optical stability and aging analysis of a variety of multi-phase dispersions, in particular suspensions and emulsions.

The optical contact angle measuring and contour analysis systems of the OCA series are high precision optical measuring devices for the measurement of interfacial parameters and phenomena.

The optical analysis of drops that hang from a dosing needle or are placed on a solid surface facilitates the determination of different surface and interfacial parameters. The contact angle that a liquid drop establishes on a solid surface characterises the solid’s wetting behaviour with said liquid.

Having measured the contact angles of multiple test liquids the surface energy of the solid can be determined and the latter can be used to calculate the work of adhesion for different liquids.

The reliable and experimentally robust measurement of the contact angle aids on the development of surface coatings, composite materials, paints and varnishes or cleaning agents. In short: the measurement of contact angle helps in all situations where solids and liquids meet and advantage is to be gained by the control of wetting and adhesion properties.

The Surface Profile Analyzer SPA 25 can measure surface topography and roughness parameters with exceptional speed and resolution.

The spinning drop video tensiometers of the SVT series are special-purpose optical instruments for measuring extremely low interfacial tensions and rheological properties. This measuring technique offers unrivalled possibilities for the analysis of surfactant effectiveness in the development of emulsions or in the enhanced oil recovery.