Somosvari B.M.,Admatis Ltd. |
Barczy P.,Admatis Ltd. |
Szoke J.,Admatis Ltd. |
Szirovicza P.,Admatis Ltd. |
Barczy T.,Admatis Ltd.
Colloids and Surfaces A: Physicochemical and Engineering Aspects | Year: 2011
Foam Casting and Utilization in Space (FOCUS, Project ID: SURE AO-019) is an industrial materials science experiment to create foams containing particles in microgravity using a special foam generator (FG). Scientific objective is to optimize the foaming parameters in order to achieve homogeneous bubble size independently of gravity and the direction of foaming. FOCUS Experiment was executed on board of the ISS (International Space Station) on the 7th February 2010. Using an aqueous suspension of SiO 2 nanoparticles at 2wt% containing 0.05wt% SDS, foams were created in three foaming cartridges (FC) with three different flow rates. Foam volumes and the average bubble sizes were compared to the terrestrial reference experiments at various foaming directions measured to gravity vector. © 2011 Elsevier B.V.
Somosvari B.M.,ADMATIS Ltd. |
Barczy P.,ADMATIS Ltd. |
Szirovicza P.,ADMATIS Ltd. |
Szoke J.,ADMATIS Ltd. |
Barczy T.,ADMATIS Ltd.
Materials Science Forum | Year: 2010
Foaming experiments in order to understand the evolution of the foam structure blown in different directions and levels of gravity have been carried out. The key elements of the experiment are the foam generator body (henceforth FG) and the controlled blowing apparatus. The FG was a polymer foam infiltrated with a suspension (distilled water, pure tenside (SDS, 0.05m%) and SiO 2 nanoparticles (2m%)) Foams were blown out at 1.5, 2, 4, 6, 10 and at 15g levels in three different directions (0, 90 and 180°, measured to the direction of the gravity vector). The elevated gravity condition was implemented in a hyper-g centrifuge (ZARM Bremen). Results show that foams can be created even at high gravity levels though the foamability and foam structure alters a lot by varying gravity level and foaming direction. At higher g-levels, under fixed gas flow rate and blowing time less foam could be produced. The average cell size varied with the blowing directions but proved constant on any gravity levels. On base of the gravity direction dependent pressure curves the foaming process was interpreted in detail. It was found that the sedimentation ruled capillary clogging is the main process by causing the gravity direction dependent foaming phenomena. The unexpected observation is that the foam stability does not depend on the gravity level. © (2010) Trans Tech Publications.
Somosvari B.M.,ADMATIS Ltd |
Barczy P.,University of Miskolc
Materials Science Forum | Year: 2014
Shelf-lives of surfactant containing water - SiO2 suspensions were investigated by observing the loss of foamability with time and by making various measurements on the compounds used. Main purposes were to discover the reason of the strong foamability decrease with time and to separate gravity driven effects. These questions arose in the frame of 'FOCUS - Foam Casting and Utilisation in Space' microgravity experiment preparations (ID: SURE AO- 019/PECS 98045, EC contract no: RITA-CT-2006-026069). Foams were prepared using special foaming cartridges, by gas introduction after loading the suspension into the porous structure of the foam generator (FG). Freshly infiltrated FG-s showed superior foamabilities, but this feature was lost after a few days of storage. Several possible chemical or physical reasons were investigated experimentally, including the direction of storage position, composition change, storage temperature, etc. Investigation of gravitydriven sedimentation and creaming tendencies were also examined using dynamic light scattering (DLS) method. These effects found to have significant impact on foamability. © (2014) Trans Tech Publications, Switzerland.