title: Preparation of raspberry-like nanocapsules by the combination of Pickering emulsification and solvent displacement technique.
abstract: Well-defined raspberry-like nanocapsules were prepared by the combination of Pickering emulsification and solvent displacement technique by using silica particles as stabilizer and hexadecane (HD) as soft template. The formation of the capsule morphology is caused by the phase separation of poly(styrene-co-4-vinyl pyridine) (poly(St-co-4-VP)) in the droplets due to the diffusion of good solvent for the (co)polymer to the aqueous continuous phase. The size of capsules was successfully reduced from tens of micrometers in the dispersion by simply stirring to the nanorange by the employment of sonication and Ostwald ripening. The formation of silica-particles-armored nanocapsules was confirmed by transmission electron microscopy (TEM), high-resolution scanning electron microscopy (HRSEM), dynamic light scattering (DLS), and zeta potential measurement. The colloidal stability and particle properties, including size and morphology, depend on the amount of HD, and copolymers, the sonication time, the dispersion pH value, the type of solvent, and the copolymer composition.
authors.affiliation: Institute of Organic Chemistry III-Macromolecular Chemistry and Organic Materials, University of Ulm, Albert-Einstein-Allee 11, 89081 Ulm, Germany.
authors.forename: Anika
authors.initials: A
authors.lastname: Schrade
authors.forename: Zhihai
authors.initials: Z
authors.lastname: Cao
authors.forename: Katharina
authors.initials: K
authors.lastname: Landfester
authors.forename: Ulrich
authors.initials: U
authors.lastname: Ziener