The wetting of a polymer brush by a melt of similar chains can have a window of complete wetting with a classical allophobic wetting transition at low grafting density sigma and an autophobic one at high sigma. However, when the melt chains are much longer than the brush chains, the contact angle alpha goes through a nonzero minimum where partial differential alpha/ partial differential sigma h...

Theories of wetting of liquids on solid surfaces under the condition that van der Waals force is dominant are briefly reviewed. We show theoretically that Zisman’s empirical equation for wetting of liquids on solid surfaces is a linear approximation of the Young–van der Waals equation in the wetting region, and we express the two parameters in Zisman’s empirical equation in terms of the dielect...

An epitaxial thin film can undergo surface instability and break up into discrete islands. The stress field and the interface interaction have profound effects on the dynamics of surface evolution. In this work, we develop a nonlinear evolution equation with a second-order approximation for the stress field and a nonlinear wetting potential for the interface. The equation is solved numerically ...

We develop a pore-scale model of wetting in a single fracture. A variable fracture aperture distribution is represented as a square lattice of conceptual pores connected by throats. We borrow concepts from network modeling of ̄ow in porous media to generate a fracture model that includes the e€ects of ̄ow in wetting layers, snap-o€, and cooperative piston-like advance. Cooperative ®lling accoun...

Surface wetting on polyelectrolyte multilayers (PEMs), prepared by alternating deposition of polydiallyldimethylammonium chloride (PDDA) and poly(styrene sulfonate) (PSS), was investigated mainly in water-solid-oil systems. The surface-wetting behavior of as-prepared PEMs was well correlated to the molecular structures of the uncompensated ionic groups on the PEMs as revealed by sum frequency g...

The wetting behavior of quenched-condensed solid D2 films has been investigated by means of light scattering. On the substrates used here (graphite and aluminum) molecular deuterium displays triple point wetting and hence dewets in the solid state, provided the temperature is high enough that thermally activated diffusion processes can take place. This manifests itself in a coarse-graining of t...

The cuticles of most springtails (Collembola) are superhydrophobic, but the mechanism has not been described in detail. Previous studies have suggested that overhanging surface structures play an important role, but such structures are not a universal trait among springtails with superhydrophobic cuticles. A novel wetting experiment with a fluorescent dye revealed the extent of wetting on expos...

This study presents a systematic analysis of wetted region due to cooling of aluminum plate by water spray impingement with respect to different water flow rates, spray nozzle heights, and subcooling. Unlike jet impingement, the wetting is not commenced upon spray impingement and there is a delay in wetness of hot test surface. After initiation, the wetting (black zone) progresses gradually to ...

background: daily administration of thyroxine has proven efficacy in treatment of children with hypothyroidism. however, the possibility of treatment with longer dosing intervals that offers flexibility and choice in maintaining euthyroid state has not been tested in children. objectives: to study the efficacy of an alternate day regimen to maintain euthyroidism in children with congenital hypo...

Considering the vulnerability of double-layer grid space structures to progressive collapse phenomenon, it is necessary to pay special attention to this phenomenon in the design process. Alternate path method is one of the most appropriate and accepted methods for progressive collapse resistant design of structures. Alternate Path Method permits local failure to occur but provides alternate pat...