TY - JOUR A1 - Kopec, Maciej A1 - Rozpedzik, Anna A1 - Lapok, Lukasz A1 - Geue, Thomas A1 - Laschewsky, Andre A1 - Zapotoczny, Szczepan T1 - Stratified Micellar Multilayers-Toward Nanostructured Photoreactors JF - Chemistry of materials : a publication of the American Chemical Society N2 - Polyelectrolyte multilayers (PEMs) with stratification of the internal structure were assembled from statistical amphiphilic copolyelectrolytes of opposite charges. These polyelectrolytes organize in aqueous solutions into micellar structures with fluoroalkyl and aromatic nanodomains, respectively, that were also preserved after deposition as thin films via layer-by-layer (LbL) electrostatic self-assembly. The unimolecular micelles, formed due to statistical compositions of amphiphilic polyelectrolytes used, were shown to suppress chain interdiffusion between adjacent layers in resulting micellar PEMs, as evidenced by spectroscopic ellipsometry, atomic force microscopy (AFM), and neutron reflectometry (NR) measurements. Additionally, hydrophobic cores of the micelles were used as hosts for photoactive molecules, namely, ferrocene and perfluorinated magnesium phthalocyanine. Stratified micellar multilayers were then deposited as hollow capsules using CaCO3 microparticles as templates. Photoinduced electron transfer (PET) between ferrocene and phthalocyanine solubilized in the polymer micelles was demonstrated to occur efficiently inside the stratified, polyelectrolyte walls of the capsules, due to the polarity gradient created by the incompatible aromatic and fluoroalkyl domains. The obtained results present a new approach to construct well-organized, self-assembled nanostructured materials for solar energy conversion. Y1 - 2016 U6 - https://doi.org/10.1021/acs.chemmater.6b00161 SN - 0897-4756 SN - 1520-5002 VL - 28 SP - 2219 EP - 2228 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Reinhold, Beate A1 - Geue, Thomas A1 - Huber, Patrick A1 - Sant, Tushar A1 - Pietsch, Ullrich A1 - Sztucki, Michael T1 - In situ and ex situ SAXS investigation of colloidal sedimentation onto laterally patterned support N2 - We report on in situ investigations of colloidal ordering during gravity sedimentation from a colloidal suspension onto a prepatterned support using a polymeric surface relief grating (SRG) as the support. The ordering of colloids with a diameter of 420 nm was investigated by means of grazing-incidence small-angle X-ray scattering (GISAXS) and transmission SAXS using a preparation cell guaranteeing stable temperature and humidity. GISAXS was used for in situ monitoring of the time evolution of colloidal ordering within the whole illuminated sample area. The onset of ordering was indicated by the increase of integrated intensity within a small time frame shortly before complete evaporation of the dispersant. Single domains of coated samples were investigated ex situ by SAXS in transmission geometry where the irradiated sample area was 200 x 200 mu m(2) only. Domains with the typical size of a few millimeters were observed varying in orientation and crystallographic structure for various positions at the sample. They were mainly oriented along the grooves of the grating, confirming the influence of the underlying grating on colloidal ordering. Y1 - 2009 UR - http://pubs.acs.org/journal/langd5 U6 - https://doi.org/10.1021/La803078b SN - 0743-7463 ER - TY - JOUR A1 - Henneberg, Oliver A1 - Pietsch, Ullrich A1 - Panzner, Tobias A1 - Geue, Thomas A1 - Finkelstein, Kenneth D. T1 - Simultaneous X-ray and visible light diffraction for the investigation of surface relief and density grating formation in azobenzene containing polymer films N2 - The development of surface relief and density patterns in azobenzene polymer films was studied by diffraction at two different wavelengths. We used x-ray diffraction of synchrotron radiation at 0.124 nm in combination with visible light diffraction at a wavelength of 633 nm. In contrast to visible light scattering x-ray diffraction allows the separation of a surface relief and a density grating contribution due to the different functional dependence of the scattering power. Additionally, the x-ray probe is most sensitive for the onset of the surface grating formation Y1 - 2006 UR - http://www.informaworld.com/smpp/title~content=t713644168~db=all U6 - https://doi.org/10.1080/15421400500383345 SN - 1542-1406 ER - TY - JOUR A1 - Reiche, Jürgen A1 - Knochenhauer, Gerald A1 - Barberka, Thomas Andreas A1 - Geue, Thomas A1 - Pietsch, Ullrich A1 - Brehmer, Ludwig A1 - Hodge, P. A1 - Tredgold, Richard H. T1 - In-plane structure of perfluorotetra decanoic acid Langmuir-Blodgett films and films formed by vacuum deposition Y1 - 1995 ER - TY - JOUR A1 - Stumpe, Joachim A1 - Geue, Thomas A1 - Fischer, Thomas M. A1 - Menzel, Henning T1 - Photochemically induced changes of structures in LB-multilayers of amphotropic polymers Y1 - 1995 ER - TY - JOUR A1 - Reiche, Jürgen A1 - Dietzel, Birgit A1 - Freydank, Anke-Christine A1 - Geue, Thomas A1 - Pietsch, Ullrich A1 - Brehmer, Ludwig T1 - Lateral structure of thermally treated oxadiazole Langmuir-Blodgett films Y1 - 1995 ER - TY - JOUR A1 - Geue, Thomas A1 - Stumpe, Joachim A1 - Pietsch, Ullrich A1 - Haak, M. A1 - Kaupp, G. T1 - Photochemically induced changes of optical anisotropy and surface of LB-multilayers built up by an amphiphilic and liquid crystalline copolymer conating azobenzene moieties Y1 - 1995 ER - TY - JOUR A1 - Reiche, Jürgen A1 - Penacorada, Florencio A1 - Geue, Thomas A1 - Pietsch, Ullrich A1 - Brehmer, Ludwig T1 - In-plane structure of uranylarachidate multilayers Y1 - 1995 ER - TY - JOUR A1 - Reiche, Jürgen A1 - Knochenhauer, Gerald A1 - Dietel, Reinhard A1 - Freydank, Anke-Christine A1 - Zetzsche, Thomas A1 - Pietsch, Ullrich A1 - Brehmer, Ludwig A1 - Barberka, Thomas Andreas A1 - Geue, Thomas T1 - Structure of thermally treated oxadiazoleamide Langmuir-Blodgett films N2 - The thermal treatment of Y-type Langmuir-Blodgett (LB) films formed from the amphiphilic derivative of 2,5- diphenyl-1,3,4-oxadiazole 1 results in changes of the molecular packing. These changes have been analysed by a combination of X-ray specular reflectivity data, X-ray grazing incidence diffraction data and scanning force microscopy images, On the basis of these experimental data we have simulated possible supramolecular structures, These simulations provide insight into the intermolecular interactions giving rise to the observed structural transitions. The crystalline structure induced by thermal treatment of the LB films is characterized by a uniaxial texture, which is correlated with the dipping direction during deposition of the LB film. Y1 - 1997 ER - TY - JOUR A1 - Reiche, Jürgen A1 - Penacorada, Florencio A1 - Geue, Thomas A1 - Pietsch, Ullrich A1 - Brehmer, Ludwig T1 - Monolayers and multilayers of uranyl arachidate : in-plane structure of uranyl arachidate multilayers N2 - The molecular in-plane structure of uranyl arachidate Langmuir-Blodgett (LB) films formed at different subphase pH values was analysed by means of X-ray grazing-incidence diffraction. For multilayers formed at low subphase pH a reorganisation of the arachidic acid film structure is confirmed. At appropriate subphase pH values, reorganisation of the film structure, e.g. via the formation of three-dimensional crystallites, is prevented by the presence of the uranyl ions and by the subsequent introduction of conformational disorder (gauche defects) in the alkyl chains. The observation of a macroscopic flow-induced in-plane texture in these uranyl arachidate LB films has profound implications for the design of ordered, supramolecular structures by the Langmuir-Blodgett technique. Y1 - 1997 ER -