TY  - JOUR
A1  - Raju, Rajarshi Roy
A1  - Koetz, Joachim
T1  - Inner rotation of Pickering Janus emulsions
JF  - Nanomaterials : open access journal
N2  - Janus droplets were prepared by vortex mixing of three non-mixable liquids, i.e., olive oil, silicone oil and water, in the presence of gold nanoparticles (AuNPs) in the aqueous phase and magnetite nanoparticles (MNPs) in the olive oil. The resulting Pickering emulsions were stabilized by a red-colored AuNP layer at the olive oil/water interface and MNPs at the oil/oil interface. The core–shell droplets can be stimulated by an external magnetic field. Surprisingly, an inner rotation of the silicon droplet is observed when MNPs are fixed at the inner silicon droplet interface. This is the first example of a controlled movement of the inner parts of complex double emulsions by magnetic manipulation via interfacially confined magnetic nanoparticles.
KW  - Janus droplets
KW  - Pickering emulsions
KW  - magnetic manipulation
KW  - gold nanoparticles
KW  - magnetite nanoparticles
Y1  - 2021
U6  - https://doi.org/10.3390/nano11123312
SN  - 2079-4991
VL  - 11
IS  - 12
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Kosmella, Sabine
A1  - Klemke, Bastian
A1  - Häusler, Ines
A1  - Koetz, Joachim
T1  - From gel-like Pickering emulsions to highly ordered superparamagnetic magnetite aggregates with embedded gold nanoparticles
JF  - Colloids and surfaces : an international journal devoted to the principles and applications of colloid and interface science ; A, Physicochemical and engineering aspects
N2  - Pickering emulsions with two types of nanoparticles, i.e., superparamagnetic magnetite nanoparticles dispersed in n-hexane and gold nanoparticles dispersed in water, were formed by rigorous mixing in presence of surface active polymeric surfactants. Monodisperse magnetite nanoparticles with a mean particle size of 4 nm were obtained by a microwave-assisted synthesis in n-hexane in presence of oleic acid, and gold nanoparticles were produced in aqueous solution in presence of the hyperbranched poly(ethyleneimine) (PEI) or sodium citrate as reducing and stabilizing agent. After mixing the prepared nanoparticle dispersions in presence of the Pluronics an intermediate gel-like phase is formed. The Pickering emulsion droplets in the intermediate phase are stabilized by both types of nanoparticles, as to be seen by cryo-SEM micrographs. After separating, solvent evaporation and redispersion in water highly ordered Pluronic-stabilized superparamagnetic magnetite nanoparticle aggregates with embedded gold nanoparticles can be obtained.
KW  - Pickering emulsions
KW  - Pluronics
KW  - Magnetite and gold nanoparticles
KW  - Ring tensiometry
KW  - Cryo-SEM
KW  - HRTEM
KW  - Magnetization measurements
Y1  - 2019
U6  - https://doi.org/10.1016/j.colsurfa.2019.03.017
SN  - 0927-7757
SN  - 1873-4359
VL  - 570
SP  - 331
EP  - 338
PB  - Elsevier Science
CY  - Amsterdam
ER  -