SINTERFACE  News, Exhibitions and Workshops

News

Software for Modelling

New Developments

A new simple bubble pressure tensiometer BPA-1P was developed and is available now. Due to its robust and compact construction it is particularly suitable for applications in practice. The instrument is portable and is equipped such that it can work as "stand-alone" instrument. Due to a special software it can be applied also for on-line process control, using the surface tension as control parameter.

The development of the new scientific bubble pressure tensiometer BPA-1S has been completed now. To reach the ultra short adsorption times of less than one millisecond, it works after the principle of Fainerman. The instrument is dedicated to users in science and development departments particularly interested in extremely short adsorption times. The new hardware is based on very precise pressure and gas flow sensors and utilises a new principle for bubble time detections.

Most simple experiments at the interface between two liquids (and also between liquid and gas) can be performed by the drop volume tensiometry. The new SINTERFACE instrument DVA-1 is a side product of the PAT1. Its use is extremely easy and thus it represents a perfect platform for those who start with interfacial studies. Due to the continuous liquid supply experiments can be performed as on-line process control.

The interfacial tension between two liquids of the same density cannot be measured by any of the standard techniques based on accurate meniscus shape or weight measurements. The only way is the direct measurement of the capillary pressure in the inner drop phase. SINTERFACE has developed the module DPA-1 as additional module for PAT-1 that allows this type of measurements. Service experiments are provided, as the module has not been developed yet as a commercially available instrument.

The ODBA-1 is another new development that provides the experimental option of measuring oscillating drops and bubbles at frequencies from about 1 Hz up to several hundred Hz, depending on the size of the used capillary. With such experiments the dilational elasticity and viscosity can be measured in a frequency interval complementary to that available by drop or bubble shape tensiometry. In this way, we have established instrumentation for relaxation experiments in a frequency range between very slow oscillations (0.01 Hz) to high exchange rates (up to few hundreds Hz).

Recenty, we developed a software package for the analysis of relaxation processes. The software allows the determination of the elasticity and viscosity of interfacial layers from the dynamic interfacial tension behaviour. The analysis can be applied to harmonic and transient relxation experiments.

As little brother, the small drop and bubble shape tensiometer PAT-2P is produced now. This low cost instrument is operated manually and provides surface and interfacial tension measurements in a way similar to the PAT-1, however, without automatic drop/bubble formation and size control. Transient relaxations can be performed by step wise changes of the drop/bubble size.

For all those, who look for a quick and cheap way to measure the surface tension of a liquid or determine its density, we developed an equipment that works as ring or plate tensiometer. What you need is an accurate laboratory balance. We propose the Sartorius balance CP64, which can be delivered together with the module, controlled by a Windows software.

Workshops

3^rd User Seminar 2D/3D Rheology

Anton Paar Germany GmbH (Ostfildern, www.anton-paar.com) and SINTERFACE Technologies (Berlin) organised a new type of user seminars, dedicated to the rheology of structured bulk phases and two-dimensional interfacial layers.

The third 2D/3D rheology seminar is scheduled for May 2010. Information you can download here.