Berlin 2005 – wissenschaftliches Programm
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CPP: Chemische Physik und Polymerphysik
CPP 14: Polymer physics at the surface
CPP 14.3: Vortrag
Montag, 7. März 2005, 17:00–17:15, TU C130
Ultra-small angle X-ray scattering at colloidal crystals on prepatterned support — •Beate Reinhold1, Thomas Geue1, Ullrich Pietsch1, and Peter Bösecke2 — 1Institut für Physik, Universität Potsdam, Am Neuen Palais 10, D-14469 Potsdam, Germany — 2European Synchrotron Radiation Faciliy, 38043 Grenoble, France
Crystalline ordering of monodisperse colloidal spheres is of great interest for many technical applications. The aim we pursue is to build up ordered structures (2D and 3D) on patterned substrates. The aim we pursue is to build up ordered structures (2D and 3D) on patterned substrates. Therefore 400 - 1000 nm sized Polystyrene particles were deposited by Gravity Sedimentation onto a substrate that is pre-structured by a surface relief grating. Besides a characterization of the surface with AFM the 3D structure can only be investigated by Ultra Small Angle X-Ray Scattering at the ID2 beamline of ESRF, Grenoble. Actually we received information-rich scattering images of samples measured in reflection and transmission geometry. From these data we could deduce 2D ordering of the colloids. For the first time we performed time-resolved measurements; in particular we measured the scattering signal of colloidal solution in-situ after deposition onto the substrate. While the whole process of drying takes up to 5 hours essential changes appeared within a time window of 5 to 15 minutes. We found that the degree of ordering was higher in the liquid phase right before complete evaporation of solvent compared with the ordering in solid phase.