TY  - JOUR
A1  - Kovach, Ildiko
A1  - Won, Jooyoung
A1  - Friberg, Stig E.
A1  - Koetz, Joachim
T1  - Completely engulfed olive/silicone oil Janus emulsions with gelatin and
chitosan
JF  - Colloid and polymer science : official journal of the Kolloid-Gesellschaft
N2  - Janus emulsions, formed by mixing two oil components (i.e., olive oil (OO) and silicone oil (SiO)) with water in the presence of two surface active biopolymers, i.e., gelatin and chitosan, are investigated in more detail. The stability of Janus droplets formed strongly depends on the polymer components used. The mixture of both biopolymers represents an extraordinary effect which can be related to the complex formation of gelatin and chitosan. Taken into account that under the given pH conditions, in the acidic pH range between 4 and 6, below the isoelectric point of gelatin, both polymers are polycations, one can conclude that non-Coulombic interactions are of relevance for the enhanced surface activity of the complexes. Dynamic interfacial tension (gamma) measurements by using the drop profile analysis tensiometry (PAT) indicate a strong adsorption of the polymer complexes at the olive oil/water interface in contrast to the silicone/water interface. In a first step, the polymer complexes are adsorbed at the interface, and in a second step, a more rigid skin-like polymer layer is formed. This first example of a polymer-stabilized Janus emulsion opens new perspectives for the application, e.g., in food emulsions or for making scaffold materials.
KW  - Janus emulsions
KW  - Interfacial tension
KW  - Ring method
KW  - Drop profile analysis tensiometry
KW  - Gelatin-chitosan composites
Y1  - 2016
U6  - https://doi.org/10.1007/s00396-016-3828-4
SN  - 0303-402X
SN  - 1435-1536
VL  - 294
SP  - 705
EP  - 713
PB  - Springer
CY  - New York
ER  - 
TY  - JOUR
A1  - Kovach, Ildiko
A1  - Rumschöttel, Jens
A1  - Friberg, Stig E.
A1  - Koetz, Joachim
T1  - Janus emulsion mediated porous scaffold bio-fabrication
JF  - Colloids and surfaces : an international journal devoted to fundamental and applied research on colloid and interfacial phenomena in relation to systems of biological origin ; B, Biointerfaces
N2  - A three dimensional biopolymer network structure with incorporated nano-porous calcium phosphate (CaP) balls was fabricated by using gelatin-chitosan (GC) polymer blend and GC stabilized olive/silicone oil Janus emulsions, respectively. The emulsions were freeze-dried, and the oil droplets were washed out in order to prepare porous scaffolds with larger surface area. The morphology, pore size, chemical composition, thermal and swelling behavior was studied by Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR) and micro-Differential Scanning Calorimetry (micro-DSC). Microscopic analysis confirmed that the pore size of the GC based sponges after freeze-drying may be drastically reduced by using Janus emulsions. Besides, the incorporation of nanoporous calcium phosphate balls is also lowering the pore size and enhancing thermal stability. (C) 2016 Elsevier B.V. All rights reserved.
KW  - Janus emulsions
KW  - Calcium phosphates
KW  - Gelatin-chitosan scaffolds
Y1  - 2016
U6  - https://doi.org/10.1016/j.colsurfb.2016.05.018
SN  - 0927-7765
SN  - 1873-4367
VL  - 145
SP  - 347
EP  - 352
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - THES
A1  - Kovach, Ildiko
T1  - Development, characterization of Janus emulsions, and their usage as a template phase for fabricating biopolymer scaffolds
Y1  - 2016
ER  -