The surface of solvent cast films of blends of cellulose propionate and fluorine (F)-containing cellulose derivatives was examined. Static wetting force measurements of blends showed a sharp decline in wetting force at low blend concentrations of the Fspecies. This indicated enrichment of the F-containing derivative at the surface. X-ray photoelectron spectroscopy (XPS) of blends revealed a sur...

The segregation behavior of the bimetallic alloys PtPd and CoCr in the case of bare surfaces and in the presence of an oxygen ad-layer has been studied by means of first-principles modeling based on density-functional theory (DFT). For both systems, change of the dband filling due to charge transfer between the alloy components, resulting in a shift of the d-band center of surface atoms compare...

Order-disorder transitions at and segregation to the (001) surface of Ni-Pt alioys have been investigated by a recently developed free energy simulation method, where the atomic interactions are described using the embedded atom method (EAM) potentials. On the Ni-rich side of the phase diagram, we observe a second order, order-disorder phase transition on the (001) surfaces at temperatures well...

In order to minimize the total energy of a disordered alloy crystal, those atoms segregate to the surface, which own the lower surface energy. In ordered systems, this energy gain has to be paid by the energy necessary to create antisite atoms in the bulk and at the surface. In strongly ordering systems, i.e. such with a large formation enthalpy, this energetic balance turns out to be unfavoura...

X-ray photoelectron spectroscopy (XPS) and low energy ion scattering spectroscopy (LEISS) have been used to study the effects of various surface preparations and thermal treatments on the composition of the near-surface region ( 7 atomic layers) and the topmost atomic layer of a polycrystalline Pd70Cu30 alloy. Palladium enrichment (relative to the bulk composition) is observed in the XPS-access...

We have investigated interdiffusion and surface segregation in molecular-beam-epitaxially-grown stacked self-assembled InAs/GaAs quantum dots. Using high-resolution cross-sectional scanning tunneling microscopy, we observe lateral variations in the vertical positions of In atoms in both the wetting layers and dot stacks. In some regions, the wetting layer thickness is much less than the dot hei...

This paper considers the segregation of a granular mixture in a rotating drum. Extending a recent kinematic model for grain transport on sandpile surfaces to the case of rotating drums, an analysis is presented for radial segregation in the rolling regime, where a thin layer is avalanching down while the rest of the material follows rigid body rotation. We argue that segregation is driven not j...

We study morphologies of thin-film diblock copolymers between two flat and parallel walls. The study is restricted to the weak segregation regime below the order-disorder transition temperature. The deviation from perfect lamellar shape is calculated for phases which are perpendicular and parallel to the walls. We examine the undulations of the inter material dividing surface and its angle with...

Segregation has been widely discussed by social scientists and especially by urban geographers and planners over the past decades. However, regardless of their focus, most of these studies view segregation as an obvious case of spatial injustice. I argue that this implicit relationship between segregation, (in) justice, and space needs to be reexamined. This paper approaches this task by review...