Richard Rowley - Academia.edu (original) (raw)
Papers by Richard Rowley
Progress in Surface Science, 2001
The theory of fluids near surfaces and in pores is reviewed and some simulations of electrolytes ... more The theory of fluids near surfaces and in pores is reviewed and some simulations of electrolytes with a continuum solvent near an electrode that agree qualitatively with experiment but that are inexplicable by current theories are outlined. Recent work with ...
The Journal of Chemical Physics, 2004
Molecular-dynamics simulations were performed to model the effect of added salt ions on the liqui... more Molecular-dynamics simulations were performed to model the effect of added salt ions on the liquid–liquid interface in a partially miscible system. Simulations of the interface between saturated phases of a model 1-hexanol+water system show a bilayer structure of 1-hexanol molecules at the interface with −OH heads of the first layer directed into the water phase and the opposite orientation for the second layer. The alignment of the polar −OH groups at the interface stabilizes a charge separation of sodium and chloride ions when salt is introduced into the aqueous phase, producing an electrical double layer. Chloride ions aggregate nearer the interface and sodium ions move toward the bulk water phase, consistent with the explanation that the −OH alignment presents a region of partial positive charges to which the hydrated chloride atoms are attracted. Ions near the interface were found to be less solvated than those in the bulk phase. An electric field was also applied to drive ions...
The Journal of Chemical Physics, 2003
Molecular dynamics simulations have been carried out for aqueous electrolyte solutions between mo... more Molecular dynamics simulations have been carried out for aqueous electrolyte solutions between model electrode surfaces. The effect of solvent model flexibility on bulk and double layer properties was observed for electrode surface charge densities of 0, ±0.1, and ±0.2 C/m2 and ion concentrations of 0, 0.5, and 1 M. Two flexible models were used to isolate the effects of flexibility from the effects of a change in the condensed-phase dipole moment. Model flexibility increases the pure water self-diffusion coefficient while a larger liquid dipole moment substantially decreases it. There is an increase in ion contact adsorption and counter ion affinity with the flexible models, suggesting that the ions are less tightly solvated. This conclusion is consistent with observed enhancements of solvated ion densities near uncharged electrodes for the flexible water case. Mobile ions in high concentration quickly damp out the electric field even at high electrode charge densities, but for dil...
The importance of liquid viscosity in chemical process design makes it one of the most measured t... more The importance of liquid viscosity in chemical process design makes it one of the most measured transport properties. Nevertheless, of the 1893 compounds in the DIPPR 801 pure-component database, liquid viscosity and its temperature dependence (at 1 atm, or 0.1 MPa) have been predicted for nearly 50% of the compounds because no experimental data are available. Unfortunately, prediction methods for liquid viscosity often fail significantly, particularly near the normal boiling point. Moreover, experimental data measured at lower temperatures are often extrapolated to higher temperatures with erroneous results. To improve liquid viscosity prediction and extrapolation of experimental data to higher temperatures, we propose an empirical rule for estimating the viscosity of organic compounds at their normal boiling point, η Lb . The proposed rule, developed and validated with the available experimental data in the DIPPR 801 database, was applied as a quality control check on the 1893 compounds in the database and was found to improve the available temperature dependent viscosity correlation in the database for 250 compounds. Of particular significance is a smooth trend within chemical families for the value of the viscosity at the normal boiling point.
International Journal of Thermophysics, 2004
A group-contribution method has been developed to estimate the heat of sublimation (?Hsub) at the... more A group-contribution method has been developed to estimate the heat of sublimation (?Hsub) at the triple point for organic solids. The correlation was developed using ?Hsub values from a training set of 218 compounds, and it was tested by comparing predicted and solid vapor pressures for 87 compounds (1103 data points). The predicted solid vapor pressures were obtained from the
Journal of Chemical and Engineering Data, 2004
A simple relationship between the solid density of organic compounds and the liquid density at th... more A simple relationship between the solid density of organic compounds and the liquid density at the triple point is presented as an extension of a previous relationship used internally by the DIPPR 801 database project. The relationship allows estimation of solid density (of the solid phase most stable at the triple point) for organic compounds over a wide range of
Journal of Chemical and Engineering Data, 2002
Tabulation of evaluated physical property constants and of their estimated uncertainties makes th... more Tabulation of evaluated physical property constants and of their estimated uncertainties makes the DIPPR database a valuable tool for developing correlations for physical properties of pure fluids. In this study, we have used the DIPPR database to develop a group-contribution method for the normal boiling point (NBP) of pure compounds. The resultant correlation uses the molecular descriptors of molecular weight
Journal of Chemical and Engineering Data, 2001
Journal of Chemical and Engineering Data, 2004
... Benjamin T. Goodman, W. Vincent Wilding, John L. Oscarson, and Richard L. Rowley*. Department... more ... Benjamin T. Goodman, W. Vincent Wilding, John L. Oscarson, and Richard L. Rowley*. Department of Chemical Engineering, 350 CB, Brigham Young University, Provo, Utah 84602. J. Chem. Eng. Data , 2004, 49 (1), pp 24–31. ...
Physical Review Letters, 2001
The conductance of sodium ions through a simplified channel-membrane system immersed in a reservo... more The conductance of sodium ions through a simplified channel-membrane system immersed in a reservoir of 1M NaCl in SPC͞E water is examined by molecular dynamics simulation. An applied external potential of 1.1 V drives the ions and water through a channel of length 25 Å producing a current of 19.6 pA, in reasonable agreement with experimental findings. The stream of ions and water molecules flows continuously because of the constant applied field and periodic boundary conditions. We also examine the potential profile across the simulation cell, the average density distributions of the various species in the reservoir and radially in the channel, and the ion velocity in the channel.
Molecular Physics, 2002
The effect of the simulation cell size and periodic boundary conditions on non-equilibrium molecu... more The effect of the simulation cell size and periodic boundary conditions on non-equilibrium molecular dynamics simulations of the structure and dynamics with explicit water molecules and ions in and near a model channel in a biological membrane is considered. The approach seems satisfactory. In particular, the presence of image channels that often contain image ions seems to have little effect
Molecular Physics, 1998
Non-equilibrium molecular dynamics (NEMD) with isobaric and isokinetic controls were used to simu... more Non-equilibrium molecular dynamics (NEMD) with isobaric and isokinetic controls were used to simulate the shear viscosity for binary mixtures of water, methanol and acetone, and for ternary mixtures. In all, 22 different liquid composition points were simulated at 298.15 K and 0.1 MPa. A new set of acetone potential parameters was developed, while slight variants to existing water and methanol models were used. Long range Coulombic interactions were computed with the Ewald sum adapted to Lees-Edwards boundary conditions as formulated in Wheeler, D. R., Fuller, N. G., and Rowley, R. L., 1997, Molec. Phys., 92, 55. The attractive (dispersive) part of the Lennard-Jones (LJ) interactions also was handled by a lattice sum. A hybrid mixing rule was used for the LJ cross interactions. Viscosities extrapolated to zero shear compared well with experimental results, having a mean absolute error of 14% and no errors greater than 30%. Although the simulations successfully predicted viscosity maxima for mixtures high in water content, the peak heights tended to be too low, probably due to the limitations of the water model. The results suggest that NEMD may be a viable means of estimating viscosities for polar liquid mixtures with an unrestricted number of components.
The Journal of Chemical Physics, 1989
Mutual diffusion coefficients for selected alkanes in carbon tetrachloride were calculated using ... more Mutual diffusion coefficients for selected alkanes in carbon tetrachloride were calculated using molecular dynamics and Lennard-Jones (LJ) potentials. Use of effective spherical LJ parameters is desirable when possible for two reasons: (i) computer time is saved due to the simplicity of the model and (ii) the number of parameters in the model is kept to a minimum. Results of this
The Journal of Chemical Physics, 1999
A simple membrane, supporting charge densities 1 and 2 ϭϪ 1 on its inner and outer surfaces, is c... more A simple membrane, supporting charge densities 1 and 2 ϭϪ 1 on its inner and outer surfaces, is considered. In addition to the electrostatic potential, the membrane interacts with the surrounding fluid by a short range van der Waals-like potential. The fluid beyond the outer surface is a three-component restricted primitive electrolyte consisting of two cations and one anion. The membrane is impermeable to one of the cations so that the fluid in the membrane and beyond the inner surface is a two-component restricted primitive electrolyte. We use Monte Carlo simulations and density functional theory to study the density profiles of the electrolyte and the charge-electrostatic potential relationship for the membrane surfaces. Even though 2 ϭϪ 1 , the potentials on the membrane surfaces are not equal and opposite. We also study a membrane consisting of a single charged plane. For both models, the density functional results are in good agreement with the simulations.
The Journal of Chemical Physics, 2000
Comparison of charged sheets and corrected 3D Ewald calculations of long-range forces in slab geo... more Comparison of charged sheets and corrected 3D Ewald calculations of long-range forces in slab geometry electrolyte systems with solvent molecules. [The Journal of Chemical Physics 112, 9253 (2000)]. Paul S. Crozier, Richard L. Rowley, Eckhard Spohr, Douglas Henderson. ...
The Journal of Chemical Physics, 2000
Molecular dynamics calculations of the electrochemical properties of electrolyte systems between ... more Molecular dynamics calculations of the electrochemical properties of electrolyte systems between charged electrodes. [The Journal of Chemical Physics 113, 9202 (2000)]. Paul S. Crozier, Richard L. Rowley, Douglas Henderson. Abstract. ...
The Journal of Chemical Physics, 2008
In superconformal filling of copper-chip interconnects, organic additives are used to fill high-a... more In superconformal filling of copper-chip interconnects, organic additives are used to fill high-aspect-ratio trenches or vias from the bottom up. In this study we report on the development of intermolecular potentials and use molecular dynamics simulations to provide insight into the molecular function of an organic additive (3-mercaptopropanesulfonic acid or MPSA) important in superconformal electrodeposition. We also investigate how the presence of sodium chloride affects the surface adsorption and surface action of MPSA as well as the charge distribution in the system. We find that NaCl addition decreases the adsorption strength of MPSA at a simulated copper surface and attenuates the copper-ion association with MPSA. The model also was used to simulate induced-charge effects and adsorption on a nonplanar electrode surface.
Journal of Chemical & Engineering Data, 1998
Absorption rates of gaseous CO 2 into aqueous diethanolamine (DEA) solutions were measured in a q... more Absorption rates of gaseous CO 2 into aqueous diethanolamine (DEA) solutions were measured in a quiescent, inverted-tube diffusiometer by monitoring the rate of pressure drop. The absorption rate was found to be insensitive to the diffusion coefficient of CO 2 in solution but very sensitive to the diffusion rate of bicarbonate, protonated DEA, and carbamate ions. Evidence also suggested that chemical reaction equilibrium is rapid relative to diffusion. The diffusion coefficient of DEA in water was also measured using a Taylor dispersion apparatus. A numerical model was developed and used to regress diffusion coefficients of bicarbonate, carbamate, and protonated amine from measured absorption rates. CO 2 absorption rates and diffusion coefficients of bicarbonate, carbamate, and protonated DEA were obtained at 298.2 K and 318.2 K in solutions containing 20, 35, and 50 mass % DEA in water.
Journal of Chemical & Engineering Data, 1997
Natural gas processors use amine treating processes to remove the acid gases HâS and COâ from gas... more Natural gas processors use amine treating processes to remove the acid gases HâS and COâ from gas streams. Absorption rates of gaseous COâ into aqueous N-methyldiethanolamine (MDEA) solutions were measured in a quiescent, inverted-tube diffusiometer by monitoring the rate of pressure drop. The absorption rate was found to be insensitive to the diffusion coefficient of COâ in solution but very
Progress in Surface Science, 2001
The theory of fluids near surfaces and in pores is reviewed and some simulations of electrolytes ... more The theory of fluids near surfaces and in pores is reviewed and some simulations of electrolytes with a continuum solvent near an electrode that agree qualitatively with experiment but that are inexplicable by current theories are outlined. Recent work with ...
The Journal of Chemical Physics, 2004
Molecular-dynamics simulations were performed to model the effect of added salt ions on the liqui... more Molecular-dynamics simulations were performed to model the effect of added salt ions on the liquid–liquid interface in a partially miscible system. Simulations of the interface between saturated phases of a model 1-hexanol+water system show a bilayer structure of 1-hexanol molecules at the interface with −OH heads of the first layer directed into the water phase and the opposite orientation for the second layer. The alignment of the polar −OH groups at the interface stabilizes a charge separation of sodium and chloride ions when salt is introduced into the aqueous phase, producing an electrical double layer. Chloride ions aggregate nearer the interface and sodium ions move toward the bulk water phase, consistent with the explanation that the −OH alignment presents a region of partial positive charges to which the hydrated chloride atoms are attracted. Ions near the interface were found to be less solvated than those in the bulk phase. An electric field was also applied to drive ions...
The Journal of Chemical Physics, 2003
Molecular dynamics simulations have been carried out for aqueous electrolyte solutions between mo... more Molecular dynamics simulations have been carried out for aqueous electrolyte solutions between model electrode surfaces. The effect of solvent model flexibility on bulk and double layer properties was observed for electrode surface charge densities of 0, ±0.1, and ±0.2 C/m2 and ion concentrations of 0, 0.5, and 1 M. Two flexible models were used to isolate the effects of flexibility from the effects of a change in the condensed-phase dipole moment. Model flexibility increases the pure water self-diffusion coefficient while a larger liquid dipole moment substantially decreases it. There is an increase in ion contact adsorption and counter ion affinity with the flexible models, suggesting that the ions are less tightly solvated. This conclusion is consistent with observed enhancements of solvated ion densities near uncharged electrodes for the flexible water case. Mobile ions in high concentration quickly damp out the electric field even at high electrode charge densities, but for dil...
The importance of liquid viscosity in chemical process design makes it one of the most measured t... more The importance of liquid viscosity in chemical process design makes it one of the most measured transport properties. Nevertheless, of the 1893 compounds in the DIPPR 801 pure-component database, liquid viscosity and its temperature dependence (at 1 atm, or 0.1 MPa) have been predicted for nearly 50% of the compounds because no experimental data are available. Unfortunately, prediction methods for liquid viscosity often fail significantly, particularly near the normal boiling point. Moreover, experimental data measured at lower temperatures are often extrapolated to higher temperatures with erroneous results. To improve liquid viscosity prediction and extrapolation of experimental data to higher temperatures, we propose an empirical rule for estimating the viscosity of organic compounds at their normal boiling point, η Lb . The proposed rule, developed and validated with the available experimental data in the DIPPR 801 database, was applied as a quality control check on the 1893 compounds in the database and was found to improve the available temperature dependent viscosity correlation in the database for 250 compounds. Of particular significance is a smooth trend within chemical families for the value of the viscosity at the normal boiling point.
International Journal of Thermophysics, 2004
A group-contribution method has been developed to estimate the heat of sublimation (?Hsub) at the... more A group-contribution method has been developed to estimate the heat of sublimation (?Hsub) at the triple point for organic solids. The correlation was developed using ?Hsub values from a training set of 218 compounds, and it was tested by comparing predicted and solid vapor pressures for 87 compounds (1103 data points). The predicted solid vapor pressures were obtained from the
Journal of Chemical and Engineering Data, 2004
A simple relationship between the solid density of organic compounds and the liquid density at th... more A simple relationship between the solid density of organic compounds and the liquid density at the triple point is presented as an extension of a previous relationship used internally by the DIPPR 801 database project. The relationship allows estimation of solid density (of the solid phase most stable at the triple point) for organic compounds over a wide range of
Journal of Chemical and Engineering Data, 2002
Tabulation of evaluated physical property constants and of their estimated uncertainties makes th... more Tabulation of evaluated physical property constants and of their estimated uncertainties makes the DIPPR database a valuable tool for developing correlations for physical properties of pure fluids. In this study, we have used the DIPPR database to develop a group-contribution method for the normal boiling point (NBP) of pure compounds. The resultant correlation uses the molecular descriptors of molecular weight
Journal of Chemical and Engineering Data, 2001
Journal of Chemical and Engineering Data, 2004
... Benjamin T. Goodman, W. Vincent Wilding, John L. Oscarson, and Richard L. Rowley*. Department... more ... Benjamin T. Goodman, W. Vincent Wilding, John L. Oscarson, and Richard L. Rowley*. Department of Chemical Engineering, 350 CB, Brigham Young University, Provo, Utah 84602. J. Chem. Eng. Data , 2004, 49 (1), pp 24–31. ...
Physical Review Letters, 2001
The conductance of sodium ions through a simplified channel-membrane system immersed in a reservo... more The conductance of sodium ions through a simplified channel-membrane system immersed in a reservoir of 1M NaCl in SPC͞E water is examined by molecular dynamics simulation. An applied external potential of 1.1 V drives the ions and water through a channel of length 25 Å producing a current of 19.6 pA, in reasonable agreement with experimental findings. The stream of ions and water molecules flows continuously because of the constant applied field and periodic boundary conditions. We also examine the potential profile across the simulation cell, the average density distributions of the various species in the reservoir and radially in the channel, and the ion velocity in the channel.
Molecular Physics, 2002
The effect of the simulation cell size and periodic boundary conditions on non-equilibrium molecu... more The effect of the simulation cell size and periodic boundary conditions on non-equilibrium molecular dynamics simulations of the structure and dynamics with explicit water molecules and ions in and near a model channel in a biological membrane is considered. The approach seems satisfactory. In particular, the presence of image channels that often contain image ions seems to have little effect
Molecular Physics, 1998
Non-equilibrium molecular dynamics (NEMD) with isobaric and isokinetic controls were used to simu... more Non-equilibrium molecular dynamics (NEMD) with isobaric and isokinetic controls were used to simulate the shear viscosity for binary mixtures of water, methanol and acetone, and for ternary mixtures. In all, 22 different liquid composition points were simulated at 298.15 K and 0.1 MPa. A new set of acetone potential parameters was developed, while slight variants to existing water and methanol models were used. Long range Coulombic interactions were computed with the Ewald sum adapted to Lees-Edwards boundary conditions as formulated in Wheeler, D. R., Fuller, N. G., and Rowley, R. L., 1997, Molec. Phys., 92, 55. The attractive (dispersive) part of the Lennard-Jones (LJ) interactions also was handled by a lattice sum. A hybrid mixing rule was used for the LJ cross interactions. Viscosities extrapolated to zero shear compared well with experimental results, having a mean absolute error of 14% and no errors greater than 30%. Although the simulations successfully predicted viscosity maxima for mixtures high in water content, the peak heights tended to be too low, probably due to the limitations of the water model. The results suggest that NEMD may be a viable means of estimating viscosities for polar liquid mixtures with an unrestricted number of components.
The Journal of Chemical Physics, 1989
Mutual diffusion coefficients for selected alkanes in carbon tetrachloride were calculated using ... more Mutual diffusion coefficients for selected alkanes in carbon tetrachloride were calculated using molecular dynamics and Lennard-Jones (LJ) potentials. Use of effective spherical LJ parameters is desirable when possible for two reasons: (i) computer time is saved due to the simplicity of the model and (ii) the number of parameters in the model is kept to a minimum. Results of this
The Journal of Chemical Physics, 1999
A simple membrane, supporting charge densities 1 and 2 ϭϪ 1 on its inner and outer surfaces, is c... more A simple membrane, supporting charge densities 1 and 2 ϭϪ 1 on its inner and outer surfaces, is considered. In addition to the electrostatic potential, the membrane interacts with the surrounding fluid by a short range van der Waals-like potential. The fluid beyond the outer surface is a three-component restricted primitive electrolyte consisting of two cations and one anion. The membrane is impermeable to one of the cations so that the fluid in the membrane and beyond the inner surface is a two-component restricted primitive electrolyte. We use Monte Carlo simulations and density functional theory to study the density profiles of the electrolyte and the charge-electrostatic potential relationship for the membrane surfaces. Even though 2 ϭϪ 1 , the potentials on the membrane surfaces are not equal and opposite. We also study a membrane consisting of a single charged plane. For both models, the density functional results are in good agreement with the simulations.
The Journal of Chemical Physics, 2000
Comparison of charged sheets and corrected 3D Ewald calculations of long-range forces in slab geo... more Comparison of charged sheets and corrected 3D Ewald calculations of long-range forces in slab geometry electrolyte systems with solvent molecules. [The Journal of Chemical Physics 112, 9253 (2000)]. Paul S. Crozier, Richard L. Rowley, Eckhard Spohr, Douglas Henderson. ...
The Journal of Chemical Physics, 2000
Molecular dynamics calculations of the electrochemical properties of electrolyte systems between ... more Molecular dynamics calculations of the electrochemical properties of electrolyte systems between charged electrodes. [The Journal of Chemical Physics 113, 9202 (2000)]. Paul S. Crozier, Richard L. Rowley, Douglas Henderson. Abstract. ...
The Journal of Chemical Physics, 2008
In superconformal filling of copper-chip interconnects, organic additives are used to fill high-a... more In superconformal filling of copper-chip interconnects, organic additives are used to fill high-aspect-ratio trenches or vias from the bottom up. In this study we report on the development of intermolecular potentials and use molecular dynamics simulations to provide insight into the molecular function of an organic additive (3-mercaptopropanesulfonic acid or MPSA) important in superconformal electrodeposition. We also investigate how the presence of sodium chloride affects the surface adsorption and surface action of MPSA as well as the charge distribution in the system. We find that NaCl addition decreases the adsorption strength of MPSA at a simulated copper surface and attenuates the copper-ion association with MPSA. The model also was used to simulate induced-charge effects and adsorption on a nonplanar electrode surface.
Journal of Chemical & Engineering Data, 1998
Absorption rates of gaseous CO 2 into aqueous diethanolamine (DEA) solutions were measured in a q... more Absorption rates of gaseous CO 2 into aqueous diethanolamine (DEA) solutions were measured in a quiescent, inverted-tube diffusiometer by monitoring the rate of pressure drop. The absorption rate was found to be insensitive to the diffusion coefficient of CO 2 in solution but very sensitive to the diffusion rate of bicarbonate, protonated DEA, and carbamate ions. Evidence also suggested that chemical reaction equilibrium is rapid relative to diffusion. The diffusion coefficient of DEA in water was also measured using a Taylor dispersion apparatus. A numerical model was developed and used to regress diffusion coefficients of bicarbonate, carbamate, and protonated amine from measured absorption rates. CO 2 absorption rates and diffusion coefficients of bicarbonate, carbamate, and protonated DEA were obtained at 298.2 K and 318.2 K in solutions containing 20, 35, and 50 mass % DEA in water.
Journal of Chemical & Engineering Data, 1997
Natural gas processors use amine treating processes to remove the acid gases HâS and COâ from gas... more Natural gas processors use amine treating processes to remove the acid gases HâS and COâ from gas streams. Absorption rates of gaseous COâ into aqueous N-methyldiethanolamine (MDEA) solutions were measured in a quiescent, inverted-tube diffusiometer by monitoring the rate of pressure drop. The absorption rate was found to be insensitive to the diffusion coefficient of COâ in solution but very