Marc Donohue

Marc Donohue
Johns Hopkins University | JHU · Department of Chemical and Biomolecular Engineering

PhD

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152
Publications
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4,154
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Publications

Publications (152)
Article
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Metal-exchanged zeolites have been widely used in industrial catalysis and separation, but fundamental understanding of their structure–property relationships has remained challenging, largely due to the lack of quantitative information concerning the atomic structures and reaction-relevant adsorption properties of the embedded metal active sites....
Preprint
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Metal-exchanged zeolites have been widely used in industrial catalysis and separation, but fundamental understanding of their structure-property relationships has remained challenging, largely due to the lack of quantitative information concerning the atomic structures and reaction-relevant adsorption properties of the embedded metal active sites....
Article
The finite-difference equation of diffusion (consistent with Einstein's evolution equation of diffusion) without the assumption of small mean free path is discussed. This equation predicts significant deviations from classical behavior for the simplest geometry: fluid in a pipe with a large density gradient, such that one end is at the Fickian limi...
Article
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This study presents a detailed model of leadership and organizational structures that parallels well-known principles of thermodynamics as they are applied to states of matter. Four types of organizational structure are explored with an emphasis on hierarchical institutions in and with which consulting psychologists spend most of their time. The mo...
Chapter
This chapter compares leadership in academia and knowledge-based companies with leadership in manufacturing companies and traditional hierarchical organizations like the military. As explained by Machiavelli 500 years ago, traditional hierarchical organizations are best led through the negative emotion of fear. However, it is counterproductive to l...
Article
Full-text available
In this paper, supercritical data has been evaluated and shown to demonstrate adsorption compression. Ono-Kondo analysis of adsorption isotherms for supercritical systems (including nitrogen, methane, and carbon dioxide on activated carbon Filtrasorb 400 and on zeolite 13X) indicates adsorption compression phenomenon at high pressure end just as in...
Article
Full-text available
A recently elucidated aspect of adsorption, compression in confined phases, is discussed. Grand Canonical Monte Carlo simulations were performed for the adsorption of Lennard–Jones molecules and new details of intermolecular interactions in adsorbed layers are analysed. It is shown that a strong attraction to a surface can cause adsorption compress...
Article
Full-text available
A succinct overview of some of the major research approaches to the study of leadership is provided as a foundation for the introduction of a multicomponent model of leadership that draws on those findings, complexity theory, and the concept of emergence. The major aspects of the model include: the personal characteristics and capacities, thoughts,...
Article
Full-text available
In previous work, lattice density functional theory equations have been recast into differential form to determine a property whose gradient is universally proportional to the diffusive flux. For color counter diffusion, this property appears as the impingement rate onto vacancies and molecules of a species whose density gradient can be influenced...
Article
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This paper is reporting new finding in the field of adsorbate-adsorbate interaction for supercritical carbon dioxide adsorption by One-Kondo model analysis. Adsorption isotherms for supercritical carbon dioxide on activated carbon Filtrasorb 400 and on zeolite 13X have been evaluated and shown to demonstrate adsorption compression phenomenon at hig...
Article
The Ono-Kondo model is used to correlate with experimental data from references for the adsorption of methane and carbon dioxide binary mixture on activated carbon Filtrasorb 400 at 318 K and on Norit R1 Extra at 298 K. CH 4-CH 4 interaction in adsorbed layer can be analyzed by using coordinates of equation (4) while CO 2-CO 2 interaction can be ev...
Article
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An analysis of classical approximations is performed for diffusion in fluids with density gradients. This approach gives a new diffusion equation taking into account the asymmetry of molecular mean-free paths and the velocity distribution in the flux term. It is shown that new model is consistent with Einstein's evolution equation for an asymmetric...
Article
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Hard sphere molecular dynamics simulations are used to study the mean free path of molecules traveling down a density gradient at fluid densities ranging between 0.05sigma(-3) and 0.7sigma(-3). Gradients are developed using semipermeable boundaries in the x-direction and, as a result, a net flow develops in the positive x-direction. Over the course...
Article
Four types of systems with different degrees of geometric constraint and intermolecular correlations were studied to determine the differences in their thermodynamics. The average configurational internal energies of these systems were calculated using Monte Carlo simulations, and the results are compared at the same temperatures and constant avera...
Article
The inconsistency between density profiles of fluids near surfaces and predictions of classical diffusion model is analyzed. A new diffusion equation and its solutions are proposed to reconcile adsorption behavior with predictions of the diffusion equation at the equilibrium limit. The classical phenomenological model of diffusion in fluids is base...
Article
A new analytical approach is proposed to model aggregation of molecules with isotropic, nearest-neighbor, attractive interactions. By treating the clustering process as a chain reaction, equations with the exact high temperature limit are derived by evaluating the occupation probabilities of nearest neighbors based on the Ono-Kondo approach for a h...
Article
Low temperature, Grand Canonical Monte Carlo simulations were used to study the adsorption of fluid layers on cubic, hexagonal, and atomically smooth substrates to determine the effects of registry and surface compression on the system. The size of the fluid molecules was fixed to be 20% larger than the substrate molecules in order to observe the t...
Article
A new approach is developed for lattice density functional theory of interacting symmetric dimers at high temperatures. Equations of equilibrium for two-dimensional square and three-dimensional cubic lattices are derived for the complete set of configurations in the first three shells around the central dimer, and rules of truncation for higher she...
Article
The structure of a fluid is analyzed by taking the equilibrium limit of a diffusion equation including the Giacomin-Lebowitz term for intermolecular interactions. This equation represents the differential mass balance in fluids with the Metropolis algorithm for fluxes; it allows a new qualitative yet analytical approximation for the direct correlat...
Article
It is shown that the classical derivation of the diffusion equation uses two incompatible assumptions: (1) the diffusion coefficient, , is assumed to be finite ( is a characteristic velocity and λ is the mean-free path); but (2) the flux is approximated in the limit of λ → 0. The second assumption results in unphysical instantaneous propagation whi...
Article
Full-text available
A lattice density functional approach is used to describe the equilibrium assembly of three types of anisotropic patchy particles into a T-structure. The T-structure is comprised of one three-patch, three two-patch, and three one-patch particles. All patches are positioned orthogonal to each other. Temperature, particle concentration, and interacti...
Article
Liquid-vapor density profiles are derived from the equilibrium limit of diffusion equation for interacting particles. These profiles are in good agreement with classical hyperbolic tangent relation. For simple Lennard-Jones fluids, predicted density distributions agree with computer simulation data, but have a slightly sharper transition zone. For...
Chapter
IntroductionNucleation in Dilute SystemsNucleation in Dense SystemsA General Approach to Nucleation TheoryFuture Work
Article
Classical phenomenological model of diffusion in fluids is based on the concept of the mean-free-path, lambda, and density distribution, n(x,t), as a function of coordinate, x, and time, t. Under the assumption thatn(x-lambda,t)-n(x+lambda,t)≈-2lambda(∂n/∂x), this model results in the classical diffusion equation,∂n(x,t)∂t=∂∂xD∂n(x,t)∂x, whereD=...
Article
Full-text available
Fick's first law describes diffusive flux as a linear function of the concentration gradient; its most popular generalization describes flux as a linear function of the chemical potential gradient. This generalization and others have been used for modeling, but the relationships between the flux and the gradients are nonlinear because the coefficie...
Article
The Kelvin equation for a compressible liquid in nanoconfinement is written in a form that takes into account not only Laplace's pressure, but also the oscillatory compression pressure. This leads to a simple analytical equation for pressure in nanocapillaries. The corrected equation is used to analyze properties of aqueous systems, including the o...
Article
Full-text available
The dependence of the diffusivity on temperature, pressure, and composition is not understood well; consequently, data is preferred significantly over correlations in most practical situations. Even in dilute gases, the contributions of attractions and repulsions to the diffusivity are difficult to understand on a molecular level without performing...
Article
Full-text available
A new lattice density functional theory (DFT) approach is proposed for symmetric dimers taking into account all possible configurations for molecules adjacent to a central dimer. Comparison with Monte Carlo simulations shows significant improvement of the proposed model compared to previously developed version of lattice DFT for dimers. It is shown...
Article
Membrane permeability and flux of pure gases can exhibit maxima with respect to temperature. For zeolites, this has been explained as a competition between surface and nonsurface diffusion within pores and as a process that depends on the diffusive activation energy and the heat of adsorption. This behavior is reproduced for nanoscale pores by usin...
Article
Influence of adsorption compression on nanocapillarity is discussed. Kelvin's equation for a compressible liquid is written in a form that takes into account not only Laplace's pressure, but also adsorption compression. This leads to a simple analytical equation for pressure in nanocapillaries. It is shown that the ratio of Laplace's pressure to th...
Article
A new approach to molecular diffusion is developed using density functionals for fluxes and the Metropolis algorithm in the mass balance equation. This procedure results in a new equation for diffusion of interacting particles which has multiple solutions and gives density distributions for coexisting and metastable phases. It is shown that the dif...
Article
It is shown that various multicomponent diffusion equations can be written in the generalized Maxwell–Stefan (MS) form by using a simple generalization of the inversion method presented in a publication by Merk [1959. Applied Scientific Research A 8, 73–99]. The new approach can be considered a reformulation of the Curtiss–Bird inversion [1999. Ind...
Article
Recently, it has been shown that adsorption of gases on solid surfaces often leads to repulsive forces between adsorbate molecules. In this paper, adsorption of molecules on a one-dimensional lattice is considered for repulsive interactions between adsorbate molecules. Exact adsorption isotherms are calculated and analyzed for finite and infinite c...
Article
Adsorbing carrier gases have a number of advantages in analytical and preparative gas chromatography, such as clearer detector signals and higher column efficiencies. This work shows that adsorbing carrier gases also may be useful because they cause the mobile phase flow rate to become unsteady after injecting a small amount of sample. This work sh...
Article
A density functional theory of diffusion is developed for lattice fluids with molecular flux as a functional of the density distribution. The formalism coincides exactly with the generalized Ono-Kondo density functional theory when there is no gradient of chemical potential, i.e., at equilibrium. Away from equilibrium, it gives Fick's first law in...
Article
Lattice density functional theory (DFT) and Monte Carlo simulations are used to probe the phase behavior and equilibrium structure of molecules with directional interactions with and without the influence of body forces. It is found that the application of a position-specific external field can be used to control the microstructure of confined flui...
Article
Canonical Monte Carlo simulations were used to study the adsorption and compression of fluid layers on model substrates with cubic, (111) fcc, and graphite geometries. The effect of the relative size of the fluid and substrate molecules on adsorption was considered for strong molecule-surface interactions. In the case of monolayer formation, it was...
Article
Full-text available
A priori information is used to derive the chemical potential as a function of density and temperature for 2D and 3D lattice systems. The functional form of this equation of state is general in terms of lattice type and dimensionality, though it contains critical temperature and critical density as parameters which depend on lattice type and dimens...
Article
Lattice gas is considered in the framework of three-dimensional Ono–Kondo theory. It is shown that a nonlinear correction to the configurational energy results in significant improvement of phase behavior, especially near the critical point. © 2003 American Institute of Physics.
Article
It is shown that an expansion of the configurational energy in powers of density allows correcting the critical behavior of Ono−Kondo theory for multilayer adsorption. The proposed approach results in a new equation relating densities in each layer with density in the bulk. This equation predicts spinodals and binodals which are in excellent agreem...
Article
Full-text available
In this project, we reformulated various solvent borne, high volatile organic compound (VOC) adhesives and adhesive primers, as cited in SERDP's Statement of Need, for application by a supercritical carbon dioxide spray process. Over the last several years, a new spray application process has been developed for polymeric based paints and other coat...
Article
A previously unstudied aspect of adsorption, compression in confined phases, is discussed. For the equilibrium of a gas on a solid surface, the strong attraction to the surface causes adsorbate molecules to attain much higher densities than those of equilibrium condensed phases. Under these conditions, adsorbate molecules repel each other and heats...
Article
Adsorption, the equilibrium between two-dimensional and three-dimensional fluids, is considered in the framework of Ono−Kondo lattice theory. A critical point correction to Ono−Kondo theory is proposed, and new approximations for binodals and spinodals are derived. These approximations describe the phase behavior near the critical point more accura...
Article
Order-disorder phase transitions in adsorbed and confined fluids with directional interactions are studied using lattice density functional theory. A new model is developed that is capable of predicting both order-disorder and condensation phase transitions. For systems with weak interactions, the results of this model are compared with both lattic...
Article
Adsorption equilibrium is calculated for slit-like pores of various sizes using lattice density functional theory (LDFT). It is shown that LDFT can predict adsorption isotherms with hysteresis loops and that different types of hysteresis loops can be obtained by varying energies of adsorbate–adsorbate and adsorbate–adsorbent interactions for differ...
Article
A lattice density functional theory for the nonrandom energy for multicomponent mixtures containing monomers with directional interactions is presented. This theory is a simplification and generalization of a lattice density functional theory developed by Aranovich and Donohue (AD) for two-dimensional and three-dimensional mixtures based upon ideas...
Article
Equilibrium self-assembly in fluids is studied in the framework of the lattice density-functional theory (DFT). In particular, DFT is used to model the phase behavior of anisotropic monomers. Though anisotropic monomers are a highly idealized model system, the analysis presented here demonstrates a formalism that can be used to describe a wide vari...
Article
A simple lattice-fluid model is presented for solute adsorption from a bulk liquid onto a solid surface in the presence of an additional thin (liquid) surface coating. In this model, solutes first absorb in this intermediate surface film before they adsorb at the solid surface. This coupling of adsorption with absorption behavior has a significant...
Article
The equilibrium between particular configurations of disordered system and block copolymer molecules was considered. The structure of the copolymer was found by its molecular configurations. Minimizing the free energy for exchange of molecules, gave a nonlinear set of coupled equations. To solve nonlinear equations of thermodynamic equilibria with...
Article
A new phenomenon, surface compression of adsorbates, is discussed for gases adsorbed on solids. The strong attraction to a surface causes adsorbate molecules to attain much higher densities than that of a normal liquid. Under these conditions, adsorbate molecules are so compressed that they repel each other. This phenomenon is discussed in terms of...
Article
The method of projections onto convex sets (POCS) is used to calculate the adsorption-energy distribution function from the adsorption integral (using a modified Langmuir local isotherm) for energetically heterogeneous surfaces. The POCS method, originally developed in the 1960s, has been successfully applied for many years to estimation problems,...
Article
Adsorption of amphiphilic dimers is analyzed in the framework of density functional Ono-Kondo theory. There are three configurations for dimers absorbed at a surface: one parallel to the surface and two perpendicular to the surface (AB and BA, with A or B touching the surface, respectively). Densities of molecules in each configuration are calculat...
Article
A lattice theory has been developed to describe the behavior of amphiphilic dimers. This theory allows analytical solutions by taking into account the most important configurations of nearest neighbors. There is an agreement between theoretical predictions and results of Monte Carlo simulations. The possibility of a lamellar phase transition of dim...
Article
Adsorbate-adsorbate interactions are analyzed in the framework of the Ono-Kondo model. The results show that, at large amounts of adsorption, intermolecular interactions in the adsorbed phase are repulsive. In the range of small adsorption, microporous systems also can show repulsions due to limitations of the adsorption space. This effect also is...
Article
The methodics and devices are presented for quantitative study of the characteristics of interaction in contact between individual fibers: friction force F in shear test, and cohesion force, i.e. contact strength p in rupture test. In experiments with cellulose fibers in various liquid media, the friction coefficient μ has been estimated, and the m...
Article
Calculations of lattice density-functional theory (DFT) are performed for systems that have both attractive and repulsive forces. Order–disorder phase transitions are observed. © 2000 American Institute of Physics.
Article
Phase loops with multiple solutions are observed in calculations of lattice density-functional theory. It is shown that the standard numerical methods for solving such problems distort the solution. A technique is proposed to obtain multiple solutions for phase equilibria in confined fluids. This method gives the entire phase equilibrium curve, inc...
Article
Here we analyze a lattice model for fluids with directional interactions in the framework of the Ono–Kondo theory. The free energy of the system is represented as an explicit function of the temperature and bulk density. It is shown that the model predicts both order–disorder and vapor–liquid phase transitions. This theory predicts a tricritical po...
Article
A model for monomers on a lattice is presented based on local density calculations that were first proposed by Ono and Kondo in 1947 and recently generalized by Aranovich, Donohue, and co-workers. The model allows one to describe the adsorption behavior of molecules at a surface (or interface), and the phase behavior of adsorbed molecules, as well...
Article
We analyze the influence of chain length on the adsorption isotherm using the framework of lattice theory. Each molecule is represented as a chain of segments occupying separate sites in the lattice. Adsorption equilibria (particularly adsorption isotherms) are analyzed for one-component and two-component mixtures of chain molecules. Copyright 1999...
Article
Van der Waals theory predicts that the attractive contribution to the compressibility factor is proportional to the inverse of temperature and volume. However, there are deviations from this linear behavior caused by both molecular attractions and molecular repulsions. Here, deviations from linearity due to repulsions are predicted by first order p...
Article
Lattice theories have been used extensively to predict and correlate liquid-liquid equilibria in mixtures. Lattice theories also have been used to predict the behavior of gases adsorbing onto solid surfaces. Here, we use a lattice model based on the ideas of Ono and Kondo to predict the phase behavior in adsorbed monolayers for systems that are bel...
Article
Hysteresis has been observed in adsorption isotherms for a number of gas-solid systems and, generally, is attributed to adsorption in mesoporous materials with capillary condensation. This behavior is classified as Type IV or Type V in the IUPAC classification scheme. Here, lattice theory is used to predict adsorption behavior in pores. The Ono-Kon...
Article
Full-text available
The current IUPAC classification of gas–solid adsorption isotherms has two deficiencies: it is incomplete and it gives the incorrect impression that adsorption isotherms are always monotonically increasing functions of pressure. However, there are many isotherms that are not monotonic and show maxima. The reason for this deficiency is that the IUPA...
Article
A new attractive term for the equation of state (EOS) of square-well fluids has been developed by using an off-lattice mean-field term in an approximate solution for the lattice gas. van der Waals theory predicts that the attractive contribution to the compressibility factor is proportional to the inverse of temperature and volume. However, there a...
Article
Adsorption at fluid–solid interfaces is considered in the framework of a lattice with boundaries. Using ideas proposed by S. Ono and S. Kondo (in“Molecular Theory of Surface Tension in Liquids” (S. Flügge, Ed.), Encyclopedia of Physics, Vol. 10, p. 134. Springer-Verlag, Berlin, 1960), a lattice model is derived, both rigorously and phenomenological...
Article
Full-text available
A detailed comparison is made of several local-composition lattice models. The models considered include several popular activity coefficient models:  the Wilson equation, Guggenheim's quasi-chemical theory (GQC), the nonrandom two-liquid theory (NRTL), and the universal quasi-chemical (UNIQUAC) theory. Also considered are three recently developed...
Article
Henry's constants for supercritical solutes are usually estimated from the infinite dilution activity coefficient and a hypothetical standard state for the solute as a pure liquid. The fugacity at this hypothetical standard state is estimated by extrapolation of the solute's vapor pressure curve beyond the critical point. Here, an alternative appro...
Article
Here we demonstrate that there is a wide range of pressures at supercritical temperatures where there is essentially monolayer coverage (i.e., there is nearly a complete layer of molecules adsorbed adjacent to the surface, but very little excess density in the second and subsequent layers). In this regime, the dependence of the Gibbs adsorption on...
Article
Full-text available
A new lattice theory is proposed to describe nonrandom behavior for multicomponent mixtures of monomers, for mixtures of monomers interacting with a polymer, and for mixtures of monomers at a surface. Based on concepts first proposed by Ono and Kondo, this new approach allows one to derive local densities around each species taking into account mol...
Article
Multilayer adsorption is calculated for a one-component vapor using ideas based on the Ono–Kondo lattice model. It is shown that this model predicts the common types of adsorption behavior: the Henry, Langmuir, and Frumkin equations as particular cases; multilayer isotherms including steps due to two-dimensional condensation; changes in the isother...
Article
Full-text available
A new model is derived for lattice systems (lattice gas and binary mixtures of monomers). This model is based on a generalization to three dimensions of the OnoâKondo equations for the density profile near a flat surface. The internal energy is calculated and compared with previous models. Unlike many previous theories, this new model has the corre...
Article
The singularity in the adsorption isotherm for macroporous and nonporous adsorbents is considered as a universal function that can be characterized with two parameters: a coefficient of proportionality,K, and an exponent,d. It is shown that the value ofKis proportional to the adsorbent surface area but does not depend on the nature of the adsorbent...
Article
Adsorption isotherms for supercritical fluids are calculated using lattice theory. Results are compared with experimental data for methane on graphon and for carbon dioxide on coal. It is shown that the model reflects the peculiar features in adsorption isotherms of supercritical fluids (in particular, a maximum in the adsorption with increasing pr...
Article
Full-text available
A new process for spraying paints and other coatings has been developed which reduces atmospheric emissions of environmentally harmful volatile organic compounds (VOCs). The liquid solvents of conventional coatings have been replaced by supercritical carbon dioxide. The carbon dioxide not only reduces viscosity, but provides additional benefits. Th...
Article
The Ono–Kondo lattice model for the density gradient near a surface is applied to surfaces where the adsorbate–adsorbent interactions are not homogeneous. While solving the general equations would be quite complex, relatively simple solutions can be obtained for periodic surfaces such as a checkerboard. It is shown that the adsorption behavior on s...
Article
Considerable progress has been made over the last two decades in the modeling of hydrogen bonding fluids. Traditionally, the properties of hydrogen bonding solutions have been predicted and correlated using lattice models to give activity coefficients. Recently, several equations of state have been developed which can be used to predict activities...
Article
The solubility behavior of solid and fluid components with supercritical fluids (SCF) is investigated using a mean field equation of state. When densities, instead of the more commonly used mole fraction and pressure, are used to illustrate solubilities, the effect of the solute's vapor pressure becomes clear. An expression for the relation between...
Article
Adsorption isotherms are analyzed for slightly soluble organic components from water for a wide range of reduced concentrations. It is shown that the behavior of these systems can be modeled by an equation of the forma = Ac/[(1 +Bc)(1 −c/c0)d] over the range ofc/c0from about 0.05 to 0.9. Hereais the adsorption amount,cis the concentration of organi...
Article
A lattice model for adsorption from binary solutions is developed using the Ono–Kondo equations. The resulting adsorption isotherm is derived and analyzed for systems with partial and complete miscibility. Results are compared with experimental data for the systems benzene–cyclohexane, benzene–heptane, benzene–nitrobenzene, and toluene–brombenzene...
Article
Full-text available
Adsorption equilibria in slit pores are calculated using an analytic solution of the classical Ono-Kondo equation with modified boundary conditions. A new equation is developed for isotherms of gas adsorption on microporous adsorbents. This equation describes isotherms of Type I in the IUPAC classification scheme for temperatures below the critical...
Article
In this paper two classes of equations of state for binary mixtures of equal-sized square-well spherical molecules are compared. The first class is perturbation theory, and the second includes several models based on local composition arguments. It is shown that second-order perturbation theory generally is in better agreement with configurational...
Article
An equation of state for multilayer adsorption is derived. This equation gives the correct thermodynamic behavior at small pressures and at the saturation vapor pressure. The equation of state is analyzed for weakly attractive and strongly attractive surfaces and results are compared with experimental data. In addition, a new relationship is obtain...
Article
A new approach for deriving the equation of state is developed. It is shown that the integral in the compressibility equation is identical to the isotherm for Gibbs adsorption in radial coordinates. The Henry, Langmuir, and Frumkin adsorption isotherms are converted into equations of state. It is shown that using Henry’s law gives an expression for...
Article
A comparison of virial theory and perturbation theory for spherical molecules is presented. A new equation of state is derived. This new model has the exact second virial coefficient behavior, converges to the correct mean-field behavior at high densities, and successfully interpolates between these two limits. This new equation of state is applied...
Article
Full-text available
A new approach to the analysis of vapor adsorption on solids is proposed. In this method the adsorption isotherm is represented as a(p) = f(p)/(1-p/ps)d where a(p) is the amount of vapor adsorbed, p is the pressure, ps is the saturation vapor pressure, f(p) is a function describing the adsorption in the first molecular layer, and d is an adjustable...
Article
The thermodynamic behavior of amphiphilic fluids is investigated by applying the sphere-and-bond formalism to the statistical associating fluid theory (SAFT); general equations are presented for obtaining microscale information from the SAFT equation. Both bulk phase and microphase equilibria for a model of a chain amphiphile dissolved in a simple...
Article
The applicability of chain equations of state to real systems is discussed in this paper. For this purpose, the authors have compared four theories: the perturbed-hard-chain theory (PHCT) of Prausnitz and coworkers, the generalized Flory (GF) and generalized Flory dimer (GFD) theories of Hall and coworkers, and the statistical associating fluid the...