8th Liquid Matter Conference September 6-10, 2011 Wien, Austria ...

P6.10Fri 911:10-14:00Permeable shells acting as containersNina Elbers, 1 Jissy Jose, 1 Marlous Kamp, 1 Arnout Imhof, 1 and Alfons vanBlaaderen 11 Utrecht University, Princetonplein 1, 3584 CC, Utrecht, NetherlandsThe aim of this study is to develop porous shells that can act as ’containers’ for certain chemicals.By manipulating the absorption and desorption behaviour of these shells, preferentially by a trigger,one could release the contents of the shells in a controlled and localized way. These systemsare for instance interesting for drug delivery purposes and for surfactant flooding, an enhanced oilrecovery (EOR) technique, in which surfactants are used to reduce the interfacial tension betweenoil and water still remaining in the rocks. In our study, porous monodisperse siloxane shells aresynthesized using a method that was developed in our group by Zoldesi et al. [Adv. Mater. (2005),17, 924]. This synthesis procedure is based on the formation of low molecular weight liquid polydimethylsiloxane(PDMS) oil droplets in a basic ammonia aqueous solution by polymerization ofthe monomer dimethyldiethoxysilane (DMDES). In a second ’seeded-growth’ step, the oil dropletsact as a template for the formation of siloxane shells upon addition of tetraethoxysilane (TEOS),which cross-links with left-over DMDES and PDMS to form a silicate/siloxane porous network.Experiments have been performed to manipulate the shell-growth step and to improve control overthe shell size and thickness. Previous experiments have already shown that the shells can be loadedwith different functional oils like silicone oil, octamethylcyclotetrasiloxane and lower hydrocarbonoils. In preliminary experiments it is investigated whether these shells can also be loaded withsurfactants for EOR purposes.10