TY - JOUR A1 - Vargas-Ruiz, Salome A1 - Schulreich, Christoph A1 - Kostevic, Angelika A1 - Tiersch, Brigitte A1 - Koetz, Joachim A1 - Kakorin, Sergej A1 - von Klitzing, Regine A1 - Jung, Martin A1 - Hellweg, Thomas A1 - Wellert, Stefan T1 - Extraction of model contaminants from solid surfaces by environmentally compatible microemulsions JF - Journal of colloid and interface science N2 - In the present contribution, we evaluate the efficiency of eco-friendly microemulsions to decontaminate solid surfaces by monitoring the extraction of non-toxic simulants of sulfur mustard out of model surfaces. The extraction process of the non-toxic simulants has been monitored by means of spectroscopic and chromatographic techniques. The kinetics of the removal process was analyzed by different empirical models. Based on the analysis of the kinetics, we can assess the influence of the amounts of oil and water and the microemulsion structure on the extraction process. (C) 2016 Elsevier Inc. All rights reserved. KW - Microemulsions KW - Decontamination KW - Surface removal KW - Kinetic analysis KW - Extraction Y1 - 2016 U6 - https://doi.org/10.1016/j.jcis.2016.03.006 SN - 0021-9797 SN - 1095-7103 VL - 471 SP - 118 EP - 126 PB - Elsevier CY - San Diego ER - TY - JOUR A1 - Poghosyan, Armen H. A1 - Arsenyan, Levon H. A1 - Shahinyan, Aram A. A1 - Koetz, Joachim T1 - Polyethyleneimine loaded inverse SDS micelle in pentanol/toluene media JF - Colloids and surfaces : an international journal devoted to the principles and applications of colloid and interface science ; A, Physicochemical and engineering aspects N2 - An atomic scale molecular dynamics simulation (100 ns) was carried out to reveal the conformational features of a cationic polyelectrolyte, i.e., hyperbranched polyethyleneimine (PEI), inside of water-in-oil microemulsion droplets stabilized by the anionic sodium dodecyl sulfate surfactant (SDS) layer. Simulations show that the polymer reorients very quickly and is localized at the headgroup region, i.e., the polymer nitrogens are close to SDS sulfur atoms. In spite of the availability of surface roughness caused by the polymer, we track a stable inverse micelle during the production run. In overall, the obtained parameters are well compared with experimental findings. (C) 2016 Elsevier B.V. All rights reserved. KW - SDS inverse micelle KW - Polyethyleneimine KW - Molecular dynamics simulations KW - Microemulsions Y1 - 2016 U6 - https://doi.org/10.1016/j.colsurfa.2016.07.018 SN - 0927-7757 SN - 1873-4359 VL - 506 SP - 402 EP - 408 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Fortes Martín, Rebeca A1 - Prietzel, Claudia Christina A1 - Koetz, Joachim T1 - Template-mediated self-assembly of magnetite-gold nanoparticle superstructures at the water-oil interface of AOT reverse microemulsions JF - Journal of colloid and interface science N2 - Hypothesis: Bimetallic magnetite-gold nanostructures are interesting candidates to combine and enhance individual properties of each metal element in catalytic and analytical applications. Microemulsions have been employed in templated synthesis of nanoparticles, and their combination with different types of nanoparticles can further mediate interactions at the water-oil interface, providing new forms of hybrid nanostructures. Experiments: Reverse water-in-oil microemulsions of droplet sizes below 50 nm were prepared from ternary mixtures of Aerosol-OT (AOT) as surfactant, incorporating 4 nm sized superparamagnetic nanoparticles (MNPs) to the hexane-pentanol oil phase and 5 nmsized polyethyleneimine-stabilized gold nanoparticles (Au(PEI)-NPs) to the water phase. The resulting isotropic L-2 phase, Winsor phases and organized nanostructures were investigated using conductometry, calorimetry, UV-Vis spectroscopy, cryoSEM and HRTEM. Findings: Droplet-droplet interactions, morphology and surfactant film properties of AOT microemulsions could be modulated in different ways by the presence of the different nanoparticles from each liquid phase. Additionally, phase separation into Winsor phases allows the formation upon solvent evaporation of films with bimetallic heterostructures on the micrometer scale. This demonstrates a new way of nanoparticle templated assembly at liquid interfaces by assisted interactions between microemulsions and nanoparticles, as a promising strategy to obtain thin films of small, isotropic nanoparticles with hierarchical ordering. KW - AOT KW - Magnetite-gold nanoparticles KW - Microemulsions KW - Percolation KW - Templated self-assembly KW - Winsor phases Y1 - 2021 U6 - https://doi.org/10.1016/j.jcis.2020.07.079 SN - 0021-9797 SN - 1095-7103 VL - 581 IS - Part A SP - 44 EP - 55 PB - Elsevier CY - Amsterdam ER -