Theory Of Capillarity Research Articles

Spreading Coefficients of Aliphatic Hydrocarbons on Water

Experiments have been performed to determine the equilibrium spreading coefficients of some aliphatic hydrocarbons (C 6C 10) on water. The thickness of a discrete lens of each hydrocarbon sample floating on a stagnant water pool was measured interferometrically and used to calculate the spreading coefficient of the hydrocarbon with the aid of Langmuir's capillarity theory. The dependences of the spreading coefficient, thus observed, on temperature (0-50°C) and on the number of carbon atoms in the hydrocarbon molecule are in qualitative agreement with the predictions based on the Lifshitz theory of van der Waals forces.

Effect of substrate temperature on the orientations of radio frequency sputtered Ba2Si2TiO8 thin films

The effect of substrate temperature on orientations of rf sputtered Ba2Si2TiO8 (BST) thin films grown on Si (100) and (111) substrates was investigated using x-ray diffraction, optical microscopy, and scanning electron microscopy. The texture of the films deposited on Si (100) substrates varies from an amorphous structure at 750 °C, to a randomly oriented polycrystalline structure, then to (001), (111), (320), and (410) orientations as the substrate temperature increases to 950 °C. The sequence of textures coincides with the decrease in the planar atomic density of the films and the increase in the BST film/substrate interfacial energy for the corresponding orientations. The films deposited on Si(111) substrates show a similar temperature dependency of textures to that observed on films deposited on Si (100) substrates, but the optimum temperature for a particular orientation shifts to higher temperature than that for deposition on Si (100) substrate. The capillarity theory of nucleation is used to explain the growth mechanism of the BST films deposited on Si substrates.

Generalized theory of capillarity for axisymmetric menisci

A high-curvature generalization of the Laplace equation of capillarity and the Young equation of capillarity (including line tension) is developed for an axisymmetric solid-liquid-fluid system. The most general expressions for the Laplace and Young equations do not assume a particular form for the specific surface free energy. However, when a particular form, i.e., ω (A) = γ (A) ∞+ C J J+ C k K, which is related to Gibbs' expression for a highly curved menisci, 1 is assumed to hold for the specific surface free energy then we are able to recover the expected simplified form of the Laplace equation. The corresponding high-curvature Young equation includes a couple which balances the surface moments at the contact line. Unfortunately, the effect of this couple could be confused with the effect of line tension in experiments which attempt to measure the dependence of the contact angle on the contact line radius.

Reply to comment: Is it really impermissible to shift the Gibbs dividing surface in the classical theory of capillarity?

ADVERTISEMENT RETURN TO ISSUEPREVArticleReply to comment: Is it really impermissible to shift the Gibbs dividing surface in the classical theory of capillarity?J. Gaydos, L. Boruvka, and A. W. NeumannCite this: Langmuir 1991, 7, 5, 1035–1038Publication Date (Print):May 22, 1991Publication History Published online1 May 2002Published inissue 22 May 1991https://doi.org/10.1021/la00053a037RIGHTS & PERMISSIONSArticle Views61Altmetric-Citations8LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (564 KB) Get e-Alerts Get e-Alerts

The Evolution of Periodic Step Arrays on Si by Surface Diffusion

AbstractPeriodic step arrays on Si(001) surfaces have been produced using photolithography, reactive ion etching and vacuum annealing. These have been studied by optical diffraction, low energy electron diffraction(LEED), and scanning tunneling microscopy (STM). The periodically varying step density on these arrays has been examined by STM. For small deviations from (100) along the [110] zone, single atomic steps dominate, while at larger angles biatomic steps are the most common; at intermediate angles the steps are of mixed character and there is some evidence for a range of unstable orientations. Interesting differences in the ratio of the areas of the two types of terrace (2×1) reconstructions are observed for the minima and maxima of the quasi- sinusoidal surfaces; these differences may be due to stresses produced by the step arrays or to differences in the line tensions associated with the two different types of steps on reconstructed Si(001) surfaces. The observations will be compared to the predictions of capillarity theory for isotropie materials. At high temperatures surface diffusion leads to a decay in amplitude of these surface gratings probably by mutual annihilation of atomic steps at the extrema. The overall rate of this process has been followed by monitoring the change in the distribution of intensity in the diffraction pattern from the grating using a He-Ne laser while the sample is annealed in UHV. With some simplifying assumptions, the intensity distribution can be directly related to the grating amplitude. The experiments are being performed for a range of grating spacings (to allow identification of the dominant transport process from scaling laws) and for a range of temperatures. The relationship between the ‘macroscopic’ observations of the shape development and the STM results will be explored.

A novel strategy for determining line tension from the shape of a liquid meniscus near a stripwise heterogeneous wall

According to the classical theory of capillarity, which does not consider the influence of line tension, a liquid meniscus in contact with a stripwise, heterogeneous wall will experience a high curvature situation at the ends of the four-phase (i.e., solid-solid-liquid-vapour) contact line. For capillary systems with finite line tension the effect on the contact line will be most pronounced at those locations where the curvature is large. Using these basic physical ideas, a strategy is proposed for using a stripwise, heterogeneous wall to evaluate the magnitude of the line tension based on the shape of the contact line. The strategy uses a combination of incremental loading coupled with the Newton-Raphson method to generate a series of non-zero line tension solutions from an initial analytical solution that corresponds to the zero line tension case.

Determination of the spreading coefficient of one liquid on another by means of interferometric measurements of liquid-lens thickness

This paper describes a new scheme for determining the spreading coefficient of one liquid on another and its application to n-decane-on-water and n-pentane-on-water systems. The scheme is based on classical Langmuir's capillarity theory for the configuration of an oil lens floating on a water surface [J. Chem. Phys., 1 (1933) 756] and an optical interference method recently devised by ourselves [Rev. Sci. Instrum., 59 (1988) 2018] which enables the measurement of the thickness of the lens. The spreading coefficient of n-decane on water has been determined to be − (0.35±0.10) mN m −1 at 25°C and tends to decrease with increasing temperature up to 5O°C. The spreading coefficient of n-pentane on water at 34.3°C has been determined to be − (0.040±0.015) mN m −1. It is concluded that the new scheme enables the determination of spreading coefficients whose magnitude may be as small as 0.1 mN m −1 or even smaller.

Is it really impermissible to shift the Gibbs dividing surface in the classical theory of capillarity?

Is it really impermissible to shift the Gibbs dividing surface in the classical theory of capillarity?

Capillarity theory for the "coexistence" of liquid and solid clusters

Capillarity theory for the "coexistence" of liquid and solid clusters

Film and line tension effects on the attachment of particles to an interface: IV. Experimental studies with bubbles in solutions of dodecyl sodium sulfate

The film and line tensions appearing when a bubble is pressed against a liquid-gas interface are measured with solutions of dodecyl sodium sulfate at two electrolyte concentrations. A strong dependence of the film and line tensions on the system geometrical parameters is found. The measured values of the line tension are in agreement with the experimental results of S. Torza and G. Mason ( Kolloid-Z. Z. Polym. 246, 593 1971) and the theory of N. V. Churaev et al. ( Kolloidn. Zh. 42, 703, 1980; J. Colloid Interface Sci. 89, 16, 1982) but are different from those of D. Platikanov et al. ( J. Colloid Interface Sci. 75, 612, 620, 1980), and A. Scheludko et al. ( in “The Modern Theory of Capillarity” (F. C. Goodrich and A. Rusanov, Eds.), Akademie-Verlag, Berlin 1981).

Estimating Macroporosity in a Forest Watershed by use of a Tension Infiltrometer

AbstractThe ability to obtain sufficient field hydrologic data at reasonable cost can be an important limiting factor in applying transport models. A procedure is described for using ponded‐flow‐ and tension‐infiltration measurements to calculate transport parameters in a forest watershed. Thirty infiltration measurements were taken under ponded‐flow conditions and at 3, 6, and 15 cm (H2O) tension. It was assumed from capillarity theory that pores >0.1‐, 0.05‐, and 0.02‐cm diam, respectively, were excluded from the transport process during the tension infiltration measurements. Under ponded flow, 73% of the flux was conducted through macropores (i.e., pores >0.1‐cm diam.). An estimated 96% of the water flux was transmitted through only 0.32% of the soil volume. In general the larger the total water flux the larger the macropore contribution to total water flux. The Shapiro‐Wilk normality test indicated that water flux through both matrix pore space and macropores was log‐normally distributed in space.

Comments on the generalization of the classical theory of capillarity

Donnees theoriques donnant en particulier une description thermodynamique des systemes contenant des interfaces fortement incurvees

Free energy formulation of the theory of capillarity

Free energy formulation of the theory of capillarity

Free dendritic growth

Free dendritic growth refers to the unconstrained development of crystals within a supercooled melt, which is the classical “dendrite problem”. Great strides have been taken in recent years in both the theoretical understanding of dendritic growth and its experimental status. The development of this field will be sketched, showing that transport theory and interfacial thermodynamics (capillarity theory) were insufficient ingredients to develop a truly predictive model of dendrite formation. The convenient, but incorrect, notion of “maximum velocity” was used for many years to estimate the behavior of dendritic transformations until supplanted by modern dynamic stability theory. The proper combinations of transport theory and morphological stability seem to be able to predict the salient aspects of dendritic growth, especially in the neighborhood of the tip. The overall development of cast microstructures, such as equiaxed zone formation, rapidly solidified microstructures etc., also seems to contain additional non-deterministic features which lie outside the current theories discussed here.

Dynamic phase transitions in a van der Waals fluid

Abstract : This paper proves the existence of traveling wave solutions connecting liquid and vapor phases in a van der Waals fluid. The main constitutive assumptions are that the fluid be an elastic fluid(with pressure given by the van der Waals equation of state) possessing a higher order correction given by Korteweg's theory of capillarity and the fluid is a conductor of heat with large specific heat at constant volume. The main mathematical tool in the analysis is the Conley-Easton theory of isolating blocks. (Author)

Book review:Molecular theory of capillarity

Book review:Molecular theory of capillarity

Cavity formation due to a contact between particles in a nonwetting liquid

A meniscus appears around the contact between a glass sphere and a glass plate immersed in mercury, as the nonwetting liquid recedes spontaneously to form a vacuum (vapor-filled) cavity. The force of adhesion between the particles in a nonwetting liquid proves to be greater than in air by the capillary contracting force created by the cavity. Measurements of cavity diameter and adhesion forces are in agreement with the predictions based on the theory of capillarity.

At the interface

Molecular Theory of Capillarity. By J.S. Rowlinson and B. Widom. Oxford University Press: 1983. Pp.327. £30, $59.

Interparticle force conferred by capillary-condensed liquid at contact points: I. Theoretical considerations

The accompanying paper (B. Elbirli, L. Vergara-Edwards, and R. W. Coughlin, J. Colloid Interface Sci. 87, 31(1982)) gives experimental results of contrary and diverse trends in the dependence of the shear stress of beds of powders upon humidity. The interpretation of these diverse trends calls upon the theory of capillarity to describe the forces conferred by liquid condensed at points of particle contact. This Part I paper reviews the theory with special emphasis on the role played by particle shape and roughness in the forces exerted by capillary-condensed liquid. Kelvin's equation is introduced to connect the curvature of the liquid surface with its relative vapor pressure. These theoretical aspects and their limitations are evoked and discussed as an introduction to experimental results reported in the Part II paper.

The thermodynamic theory of capillarity under the hypothesis of a continuous variation of density

The thermodynamic theory of capillarity under the hypothesis of a continuous variation of density