Micromodels with a simplified porous network that represents geological porous media have been used as experimental test beds for multiphase flow studies in the petroleum industry. We present a new method to fabricate reservoir micromodels with heterogeneous wetting properties. Photopatterned, copolymerized microstructures were fabricated in a bottom-up manner. The use of rationally designed co...

The wetting of rough surfaces remains a subject of active investigation by scientists. The contact angle (CA) is a traditional parameter used to characterize the hydrophobicity/philicity of a solid surface. However, it was found recently that high CAs can coexist with strong adhesion between water and a solid surface in the case of the so-called 'rose petal effect'. Several additional parameter...

We study the thickness of wetting layers in the binary-liquid mixture cyclohexane methanol. Far from the bulk critical point, the wetting layer thickness is independent of temperature, resulting from the competition between van der Waals and gravitational forces. Upon approaching the bulk critical temperature [t=(T(c)-T)/T(c)-->0], we observe that the wetting layer thickness diverges as t(-beta...

We examine the wettability of rough surfaces through a measurement approach that harnesses a wrinkling instability to produce model substrate topographies. Specifically, we probe the wetting of liquids on anisotropic micro-wrinkled features that exhibit well-defined aspect ratios (amplitude versus wavelength of the wrinkles) that can be actively tuned. Our study provides new insight into the we...

One of the most questionable issues in wetting is the force balance that includes the vertical component of liquid surface tension. On soft solids, the vertical component leads to a microscopic protrusion of the contact line, that is, a 'wetting ridge'. The wetting principle determining the tip geometry of the ridge is at the heart of the issues over the past half century. Here we reveal a univ...

AIM To compare the sealing ability of the same root fillings when measured by a conventional fluid transport method that uses water or by a modified fluid transport method that uses a wetting fluid as tracer. METHODOLOGY The amount of fluid transport along the same root fillings (AH26, cold lateral compaction of gutta-percha) was measured in a cross-over design in fluid transport set-ups usin...

Wetting and dewetting of structured and imprinted surfaces is discussed from a theoretical point of view. An appropriate separation of length scales is used in order to eliminate irrelevant parameters from the theory. This leads to a general description of the wetting phase which can exhibit various morphologies such as droplets, channels or films. We discuss some general features of heterogene...

Even a single-component liquid may have more than two liquid states. The transition between them is called a 'liquid-liquid transition' (LLT). Such LLTs have recently attracted considerable attention mainly because of the fundamental interest in the physical origin of this counter-intuitive phenomenon. In this study, we report the first observation of wetting effects on LLT for a molecular liqu...

We present a theoretical study of wetting phenomena and interactions between liquid–vapor interfaces based on the density functional theory. The focus is mostly on the impact of long-range van der Waals interactions both within the fluid and between the fluid and substrate. For the latter, we consider two models – hard wall and soft wall approximations – differing by the role of steric effects ...

Creating surfaces capable of resisting liquid-mediated adhesion is extremely difficult due to the strong capillary forces that exist between surfaces. Land snails use this to adhere to and traverse across almost any type of solid surface of any orientation (horizontal, vertical or inverted), texture (smooth, rough or granular) or wetting property (hydrophilic or hydrophobic) via a layer of mucu...