Tittel: Electrohydrodynamics and particle sintering as methods for production of microporous capsules
Veileder: Jon Otto Fossum
Sammendrag: Capsules of all sizes are used in engineering, scientific and pharmaceutical purposes. They can function as sealed or porous compartments in order to regulate material flow. In this thesis, the fabrication of porous spherical capsules with diameters ranging from 0.4 mm to 1.2 mm is investigated. Soft capsules were fabricated by making silicone oil droplets in castor oil, and covering the droplets with 40 $\mu$m polystyrene beads utilising electrohydrodynamic effects. The beads on the droplets were then sintered by heating to the glass transition temperature of polystyrene, successfully fabricating rigid porous capsules encapsulating the silicone oil droplet. The capsules were analysed in micropipette aspiration experiments, where the capsules could be emptied by sucking the encapsulated oil droplet out. The capsules were found to be remarkably rigid. Emptied capsules were analysed in a scanning electron microscope, showing sintering necks with cross sections between 7 $\mu$m and 19 $\mu$m.