We report a numerical study of equilibrium phase diagrams and interfacial properties of bulk and confined colloid-polymer mixtures using grand canonical Monte Carlo simulations. Colloidal particles are treated as hard spheres, while the polymer chains are described as soft repulsive spheres. The polymer-polymer, colloid-polymer, and wall-polymer interactions are described by density-dependent p...

Nematic liquid crystals at rough and fluctuating interfaces are analyzed within the Frank elastic theory and the Landau-de Gennes theory. We study specifically interfaces that locally favor planar anchoring. In the first part we reconsider the phenomenon of Berreman anchoring on fixed rough surfaces, and derive new simple expressions for the corresponding azimuthal anchoring energy. Surprisingl...

To characterize nontrivial boundary conditions of a liquid flowing past a solid, the slip length is commonly used as a measure. From the profile of a retracting liquid front (e.g., measured with atomic force microscopy), the slip length can be extracted with the help of a Stokes model for a thin liquid film dewetting from a solid substrate. Specifically, we use a lubrication model derived from ...

A simple and rapid stability indicating method based on capillary zone electrophoresis has been developed and validated for the analysis of buserelin (BUS). The best separations were achieved by using a bare fused silica capillary (75 m i.d.; 65.5 cm total, 57.0 cm effective length), phosphate buffer (pH = 3.00; 26.4 mM), at 35 °C. The sample was hydrodynamically injected at 50 mbar for 5 seco...

Adhesion issues are present in many disciplines such as, for example, surface science, microrobotics or MEMS design. Within this framework, this paper presents a study on capillary forces due to capillary condensation. A simulation tool had already been presented using Surface Evolver and Matlab to compute the shape of a meniscus in accordance with the Kelvin equation and contact angles. The nu...

Biological surfaces (plant leaves, lizard and insect attachment pads, fish scales, etc.) have remarkable properties due to their hierarchical structure. This structure is a consequence of the hierarchical organization of biological tissues. The hierarchical organization of the surfaces allows plants and creatures to adapt to energy dissipation and transition mechanisms with various characterist...

The surface free energy, or surface tension, of a liquid interface gives rise to a pressure jump when the interface is curved. Here we show that a similar capillary pressure arises at the interface of soft solids. We present experimental evidence that immersion of a thin elastomeric wire into a liquid induces a substantial elastic compression due to the solid capillary pressure at the bottom. W...

a capillary electrophoresis method was used for assay of some degradation products of carvedilol. the optimized parameters were as; running buffer 80 mm acetate dissolved in methanol/ethanol mixture (65:35 v/v), applied voltage of 19 kv, temperature is 20 ºc and the wavelength range of 200-350 nm. the results indicate that the proposed ce method could effectively separate carvedilol from its de...

Adaptive optics (AO) is a revolutionary technology that enhances the quality of astronomical images by correcting aberrations in them caused by atmospheric turbulence and distortions in the primary mirrors of large telescopes. The technology relies on manipulating arrays of microactuator devices mounted behind a deformable secondary mirror to correct errors in wave-fronts of incoming light. Cur...

MEMS (micro-electromechanical systems) devices often suffer from stiction induced reliability problems. Although a theoretical framework to describe stiction in MEMS is under development in the scientific community, experimental data are still scarce. We have developed a MEMS device that can be used to electronically measure sidewall surface forces in situ, i.e. on chip. To be able to use it, w...