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Journal ArticleDOI

Ueber das Zeitgesetz des kapillaren Aufstiegs von Flüssigkeiten

01 Jul 1918-Colloid and Polymer Science (KOLLOIDN ZHURNAL)-Vol. 23, Iss: 1, pp 15-15
About: This article is published in Colloid and Polymer Science.The article was published on 1918-07-01 and is currently open access. It has received 1052 citations till now.
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Journal ArticleDOI
TL;DR: A review of experimental work on freezing and melting in confinement is presented in this paper, where a range of systems, from metal oxide gels to porous glasses to novel nanoporous materials, are discussed.
Abstract: A review of experimental work on freezing and melting in confinement is presented. A range of systems, from metal oxide gels to porous glasses to novel nanoporous materials, is discussed. Features such as melting-point depression, hysteresis between freezing and melting, modifications to bulk solid structure and solid-solid transitions are reviewed for substances such as helium, organic fluids, water and metals. Recent work with well characterized assemblies of cylindrical pores like MCM-41 and graphitic microfibres with slit pores has suggested that the macroscopic picture of melting and freezing breaks down in pores of molecular dimensions. Applications of the surface force apparatus to the study of freezing and melting phenomena in confinement are discussed in some detail. This instrument is unique in allowing the study of conditions in a single pore, without the complications of pore blockage and connectivity effects. The results have confirmed the classical picture of melting-point depression in larger pores, and allowed the direct observation of capillary condensation of solid from vapour. Other results include the measurement of solvation forces across apparently fluid films below the bulk melting point and a solid-like response to shear of films above the bulk melting point. These somewhat contradictory findings highlight the difficulty of using bulk concepts to define the phase state of a substance confined to nanoscale pores.

515 citations

Journal ArticleDOI
01 May 2014-Langmuir
TL;DR: A more generalized spontaneous imbibitions model is developed by considering the different sizes and shapes of pores, the tortuosity of imbibition streamlines in random porous media, and the initial wetting-phase saturation and test results show that the generalized model can be used to characterize the spontaneous imbIBition behavior of many different porous media.
Abstract: Spontaneous imbibition of wetting liquids in porous media is a ubiquitous natural phenomenon which has received much attention in a wide variety of fields over several decades. Many traditional and recently presented capillary-driven flow models are derived based on Hagen–Poiseuille (H–P) flow in cylindrical capillaries. However, some limitations of these models have motivated modifications by taking into account different geometrical factors. In this work, a more generalized spontaneous imbibition model is developed by considering the different sizes and shapes of pores, the tortuosity of imbibition streamlines in random porous media, and the initial wetting-phase saturation. The interrelationships of accumulated imbibition weight, imbibition rate and gas recovery and the properties of the porous media, wetting liquids, and their interactions are derived analytically. A theoretical analysis and comparison denote that the presented equations can generalize several traditional and newly developed models fr...

476 citations

Journal ArticleDOI
TL;DR: In this paper, the principles underlying common techniques for actuation of droplets and films on homogeneous, chemically patterned, and topologically textured surfaces by modulation of normal or shear stresses are reviewed.
Abstract: Development and optimization of multifunctional devices for fluidic manipulation of films, drops, and bubbles require detailed understanding of interfacial phenomena and microhydrodynamic flows Systems are distinguished by a large surface to volume ratio and flow at small Reynolds, capillary, and Bond numbers are strongly influenced by boundary effects and therefore amenable to control by a variety of surface treatments and surface forces We review the principles underlying common techniques for actuation of droplets and films on homogeneous, chemically patterned, and topologically textured surfaces by modulation of normal or shear stresses

474 citations


Cites background from "Ueber das Zeitgesetz des kapillaren..."

  • ...…by −Le2 ln(1 − L/Le) − Le L = f γlv Pc cos θ t/µ, where µ is the liquid viscosity, f is a geometric coefficient depending on the conduit geometry, and Le = γlv Pc cos θ/(ρg Ac) is the final equilibrium height determined by the balance of surface tension and gravity (Langbein 2002, Lucas 1918)....

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Journal ArticleDOI
15 Aug 2000
TL;DR: An overview and detailed analysis of the classical theory of capillarity is presented, and a simplified relation for the capillary rise dynamics in the case of strong depletion of the interfacial region is obtained, in qualitative agreement with the experimental behavior.
Abstract: An overview and detailed analysis of the classical theory of capillarity is presented. A number of known equations of capillary rise dynamics are shown to be different limiting cases of one rather general equation. Some internal inconsistencies of the classical equations are pointed out. The role of nonlinear dissipation and flow pattern effects in the front zone of the liquid column and near the capillary entrance is discussed. Numerical simulations and experimental data demonstrating some characteristic types of dynamic behavior predicted by the theory are reported. Special attention is paid to the capillary rise of surfactant solutions. As applied to this special case, the existing theory is substantially elaborated by setting up a closed system of equations describing the surfactant transport and relaxation processes in the adsorption layer. A simplified relation for the capillary rise dynamics in the case of strong depletion of the interfacial region is obtained, which is in qualitative agreement with the experimental behavior.

447 citations

Journal ArticleDOI
Erik Kissa1
TL;DR: The fundamentals of wetting and wicking are reviewed in this article, where wetting is defined as the displacement of a fiber-air interface with a fiber liquid interface, while wicking is the spontaneous flow of a liquid in a porous subspace.
Abstract: The fundamentals of wetting and wicking are reviewed. Wetting is the displacement of a fiber-air interface with a fiber-liquid interface. Wicking is the spontaneous flow of a liquid in a porous sub...

362 citations