Due to the importance of super-hydrophobic silica aerogel powder as a material in the field of energy saving, its wettability in the presence of various surfactants was investigated. One anionic and two non-ionic surfactants with different molecular structures were used as wetting and dispersing agents. Wetting properties of the aerogel powders were investigated by the contact angle measure...

This paper describes the effects of graft architecture of poly(N-isopropylacrylamide) (PIPAAm) brush surfaces on thermoresponsive aqueous wettability changes and the temperature-dependent hydrophobic interaction of steroids in silica capillaries (I.D.: 50 μm). PIPAAm brushes were grafted onto glass substrates by surface-initiated atom transfer radical polymerization (ATRP) that is one of the li...

We use molecular dynamics simulations of the SPC-E model of liquid water to derive probability distributions for water density fluctuations in probe volumes of different shapes and sizes, both in the bulk as well as near hydrophobic and hydrophilic surfaces. Our results are obtained with a biased sampling of coarse-grained densities that is easily combined with molecular dynamics integration al...

Zinc oxide nano-particles with the average diameter of about 25 nm were modified with different mole ratios of trimetoxyvinyl silane (TMVS) and oleic acid, as coupling agents, in order to modify their surface properties and render them more hydrophobic. Then, dispersibility of the surface modified nano-particles was examined in some monomers with different levels of hydrophobicity, including me...

The sensitivity of an elastin-like polypeptide (ELP) to environmental stimuli is used to reversibly immobilize a fusion partner, thioredoxin (TRX), onto a hydrophobic surface. An ELP, fused to TRX at its C-terminus, adsorbs onto a hydrophobic self-assembled monolayer (SAM) on gold above its inverse phase transition temperature (Tc) and is resolubilized from the surface when the solution tempera...

While biotechnological applications of arginine (Arg) as a solution additive that prevents protein aggregation are increasing, the molecular mechanism of its effects remains unclear. In this study, we investigated the Arg-lysozyme complex by high-resolution crystallographic analysis. Three Arg molecules were observed to be in close proximity to aromatic amino acid residues of the protein surfac...

Applying the contact density chain-growth algorithm to lattice heteropolymers, we identify the conformational transitions of a nongrafted hydrophobic-polar heteropolymer with 103 residues in the vicinity of a polar, a hydrophobic, and a uniformly attractive substrate. Introducing only two system parameters, the numbers of surface contacts and intrinsic hydrophobic contacts, respectively, we obt...

We investigate the role of viscous forces on the wetting of hydrophobic, semi-hydrophobic, and hydrophilic textured surfaces as second-order effects. We show that during the initial contact, the transition from inertia- to viscous-dominant regime occurs regardless of their surface topography and chemistry. Furthermore, we demonstrate the effect of viscosity on the apparent contact angle under q...

Liquid behaviors, including droplet condensation and frost melt water retention, of fins during frosting and defrosting processes on three aluminum fins with different surface characteristics under winter operating conditions of an air source heat pump were investigated. The effects of the surface characteristics, including the contact angle and the contact angle hysteresis, were analyzed. Drop...

Effects of hydrophobic surface on skin-friction drag are investigated through direct numerical simulations of a turbulent channel flow. Hydrophobic surface is represented by a slip-boundary condition on the surface. When a slip-boundary condition is used in the streamwise direction, the skin-friction drag decreases and turbulence intensities and turbulence structures, near-wall streamwise vorti...