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Recipes for biopolymers and surfactants for the fixation of flow induced structures

The deformation of the droplets suspended to shear forces generally increases by lowering the interfacial tensions of the reacting liquids. Different types of oil-soluble emulsifiers were used in order to increase surface areas. This concept can also be used for the synthesis of smaller, micron-sized particles. In order to get more insight into basic mechanisms of interfacial processes, surface forces and surfactant aggregation processes under static and dynamic conditions were investigated.

The kinetics of the membrane formation and the surface viscosity have been studied by observing adsorption behaviour using a pendant drop, the DuNouy ring method and a deep channel viscometer. The basic structures of these surfactant membranes were also investigated using Brewster-Angle-Microscopy. The results indicate the formation of structured surfactant monolayers and food-emulsifier-polysaccharide complexes. There are significant differences between the introduced emulsifiers. But all investigated surfactants are suitable to improve the droplet deformation.

The data, thus obtained, were used to investigate deformation and bursting of droplets, skin formation and fixation of flow induced droplet structures.

Non-spherical capsules are characterised by relatively large surface areas and this might improve accumulation times in the stomach or intestine walls. These processes can also lead to more efficient drug incorporation. Further investigations are required to develop functional microcapsules in which the permeability is controlled by changes of temperature, pH, or chemical compounds. Such smart microcapsules can be synthesized by using non-spherical particles as a kind of precursor, which is modified and coated in a second step by a multifunctional shell.


Jan LAMMERS, (Senior scientist)
Tél.: +31-10-4605911
Fax: +31-10-4605255