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  - 
TY  - JOUR
A1  - Raju, Rajarshi Roy
A1  - Kosmella, Sabine
A1  - Friberg, Stig E.
A1  - Koetz, Joachim
T1  - Pickering Janus emulsions and polyelectrolyte complex-stabilized Janus gels
JF  - Colloids and surfaces : an international journal devoted to the principles and applications of colloid and interface science ; A, Physicochemical and engineering aspects
N2  - Janus emulsions, containing olive oil (OO) and silicone oil (SiO), were formed in presence of polyelectrolyte complex particles, i.e., gelatin-sodium polyacrylate (NaPAA) complexes. The diameter of completely engulfed Janus droplets can be tuned between 50 and 200 mu m by varying the gelatin/NaPAA complex particle size between 200 and 400 nm. The gelatin/NaPAA complex particles adsorbed at the olive oil interface decrease the interfacial tension and stabilize the resulting completely engulfed Pickering Janus emulsions. Long-term stable Janus gels can be synthesized in presence of gelatin/sodium carboxymethylcellulose (NaCMC) mixtures. In that case Coulombic forces are of relevance with regard to the stabilization of the Janus droplets embedded in a gelatin/NaCMC gel matrix. Janus gels show elastic reological behavior and thixotropic properties.
KW  - Pickering Janus emulsions
KW  - Janus gels
KW  - Interfacial tension
KW  - Ring tensiometry
KW  - Gelatin-NaCMC
KW  - Gelatin-NaPAA composites
Y1  - 2017
U6  - https://doi.org/10.1016/j.colsurfa.2017.08.022
SN  - 0927-7757
SN  - 1873-4359
VL  - 533
SP  - 241
EP  - 248
PB  - Elsevier
CY  - Amsterdam
ER  -