Tobias Sokolowski
Beiersdorf
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Publication
Featured researches published by Tobias Sokolowski.
Lipids | 2007
Anja Heins; Tobias Sokolowski; Heiko Stöckmann; Karin Schwarz
The location and the resulting chemical microenvironment of the antioxidant propyl gallate (PG) was studied in micellar solutions using the cationic emulsifier cetyl trimethyl ammonium bromide (CTAB), the anionic emulsifier sodium dodecyl sulphate (SDS) and the non-ionic emulsifier Brij 58 (polyoxyethylene-20-cetyl ester). T1 relaxation time of the aromatic protons of PG was investigated in micellar solutions and compared with that in aqueous solution in the absence of emulsifier. The relaxation time of the PG portion that is solubilized in the micelle (T1,eff) was calculated from the partition behavior of PG in micellar solution. From the 1D-1H spectrum, the alteration in the electron density of the aromatic protons and the alteration in the peak shape of the emulsifier headgroup and alkyl chain proton signals were indicative of the location of propyl gallate in the different micelles. Nuclear Overhauser effects (NOE) made it possible to deduce the exact location of PG by calculation of the relative NOEs. Marked differences were found for the location of PG in CTAB, SDS and Brij 58 micelles. PG was found to be located in the palisade layer of CTAB micelles, in the region of the polyoxyethylene chain of Brij micelles and in the Stern layer of SDS micelles. For careful study of the location of antioxidants and therefore to be able to characterize the chemical microenvironment of the antioxidants is crucial for understanding differences in antioxidant activities as a function of lipid surfaces. The application of spectroscopic methods may help to optimize the antioxidant activity to inhibit lipid oxidation at surfaces that are formed in a wide range of foods (emulsions), cosmetics, pharmaceuticals (emulsions and carrier systems) and of biological membranes (LDL-particles).
Journal of Colloid and Interface Science | 2010
Petra Kudla; Tobias Sokolowski; Bernhard Blümich; Klaus-Peter Wittern
The phase behavior of a mixture containing a surfactant, fatty alcohols and water has been analyzed. Depending on the amount of surfactant, i.e. N-(3-dimethylaminopropyl) octadecanamide, the emulsion-like system forms different microstructures. With increasing surfactant content the formulation evolves from a system with lyotropic lamellar phases to a system with crystal layer phases. (13)C-CPMAS NMR studies carried out at varying surfactant levels showed significant differences in the behavior of the system. Using (2)H and (13)C-CPMAS NMR, X-ray scattering, DSC and polarization microscopy a phase diagram of this system could be derived. Additionally, ultrasonic velocity measurements showed that the ripening process of the emulsions can take up to 2 weeks and longer.
Lipids | 2007
Anja Heins; Donald B. McPhail; Tobias Sokolowski; Heiko Stöckmann; Karin Schwarz
Journal of Colloid and Interface Science | 2007
Cécile Alberola; Thomas Dederichs; Detlef Emeis; Martin Möller; Tobias Sokolowski; Klaus-Peter Wittern
Archive | 2005
Ludger Kolbe; Uwe Pfannenbecker; Inge Kruse; Tobias Sokolowski; Jeannine Immeyer; Karen Tom Dieck; Gerd Dannhardt
Cosmetics and toiletries | 2001
K. H. Diec; A. Eitrich; T. Schmidt; Tobias Sokolowski; J. Schreiber
Archive | 2002
Andreas Bleckmann; Detlef Emeis; Jens Nielsen; Heidi Riedel; Tobias Sokolowski
Cosmetics and toiletries | 2002
K. H. Diec; Tobias Sokolowski; Klaus-Peter Wittern; J. Schreiber; Wolfgang Meier
Journal of Colloid and Interface Science | 2010
Petra Kudla; Tobias Sokolowski; Bernhard Blümich; Klaus-Peter Wittern
Archive | 2012
Petra Kudla; Tobias Sokolowski; Sandra Saladin