Dahl, VerenaFriedrich, AchimMeyer, JürgenVenzmer, JoachimBelkoura, LhoussaineStrey, ReinhardMayer, ChristianMichel, RaphaelGradzielski, Michael2019-09-162019-09-162018-01-18https://depositonce.tu-berlin.de/handle/11303/10026http://dx.doi.org/10.14279/depositonce-9017The aim of our work was to study the structure of a typical modern cosmetic oil-in-water emulsion (o/w-emulsion), based on the emulsifier polyglyceryl-3 dicitrate/stearate and glycerylstearate/stearyl alcohol as consistency enhancer. We have used a systematic approach building up the cosmetic emulsion step by step, characterizing all systems by using Small Angle Neutron Scattering (SANS), Differential Scanning Calorimetry (DSC), Freeze Fracture Transmission Electron Microscopy (FF-TEM), light microscopy and rheology. The starting point was the pure emulsifier in water, which was shown to form lamellar stacked bilayers with a spacing of 7 nm, coexisting with polydisperse unilamellar vesicles in the sub-µm range. Upon addition of consistency enhancer, also multilamellar vesicles could be obtained. Then, oil has been added stepwise, until finally a complete cosmetic o/w-emulsion was obtained. In the final emulsion, oil droplets with sizes in the µm range are surrounded by multiple, irregularly spaced bilayer structures and vesicles. Approximately 30% of the water present in the system shows a restricted mobility (“encapsulated water”) according to PFG-NMR. Crucial for the viscosity build-up is the presence of the oil droplets; a cream-like consistency is obtained by steric interaction of oil droplets and crystalline bilayer structures in the aqueous phase of the emulsion.en540 Chemie und zugeordnete WissenschaftenemulsionformulationstructurebilayersscatteringSANSDSCelectron microscopyFF-TEMPFG-NMR spectroscopyArticle2019-07-312504-5377