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Comments on "Thermophysical Properties of para-Anisaldehyde (1) + Chlorobenzene (2) at Temperatures of (303.15, 313.15, and 323.15) K and a Pressure of 0.1 MPa" (Baskaran, R.; Kubendran, T. R. J. Chem. Eng. Data 2008, 53, 978-982)

Description: Comments regarding the article, "Thermochemical properties of para-anisaldehyde (1) + chlorobenzene (2) at temperatures of (303.15, 313.15, and 323.15) K and a pressure of 0.1 MPa," published in 2008 in the Journal of Chemical and Engineering Data.
Date: July 19, 2008
Creator: Jouyban, Abolghasem & Acree, William E. (William Eugene)
Partner: UNT College of Arts and Sciences

Solubility of Phenothiazine in Water, Ethanol, and Propylene Glycol at (298.2 to 338.2) K and Their Binary and Ternary Mixtures at 298.2 K

Description: Article on the solubility of phenothiazine in water, ethanol, and propylene glycol at (298.2 to 338.2) K and their binary and ternary mixtures at 298.2 K.
Date: June 2, 2011
Creator: Ahmadian, Somaieh; Panahi-Azar, Vahid; Fakhree, Mohammad Amin Abolghassemi; Acree, William E. (William Eugene) & Jouyban, Abolghasem
Partner: UNT College of Arts and Sciences

Solubility of 2-Hydroxybenzoic Acid in Water, 1-Propanol, 2-Propanol, and 2-Propanone at (298.2 to 338.2) K and Their Aqueous Binary Mixtures at 298.2 K

Description: Article discussing the solubility of 2-hydroxybenzoic acid in water, 1-propanol, 2-propanol, and 2-propanone at (298.2 to 338.2) K and their aqueous binary mixtures at 298.2 K.
Date: October 25, 2012
Creator: Fakhree, Mohammad Amin Abolghassemi; Ahmadian, Somaieh; Panahi-Azar, Vahid; Jouyban, Abolghasem & Acree, William E. (William Eugene)
Partner: UNT College of Arts and Sciences

Intermolecular potential parameters and combining rules determined from viscosity data

Description: The Law of Corresponding States has been demonstrated for a number of pure substances and binary mixtures, and provides evidence that the transport properties viscosity and diffusion can be determined from a molecular shape function, often taken to be a Lennard-Jones 12-6 potential, that requires two scaling parameters: a well depth {var_epsilon}{sub ij} and a collision diameter {sigma}{sub ij}, both of which depend on the interacting species i and j. We obtain estimates for {var_epsilon}{sub ij} and {sigma}{sub ij} of interacting species by finding the values that provide the best fit to viscosity data for binary mixtures, and compare these to calculated parameters using several 'combining rules' that have been suggested for determining parameter values for binary collisions from parameter values that describe collisions of like molecules. Different combining rules give different values for {sigma}{sub ij} and {var_epsilon}{sub ij} and for some mixtures the differences between these values and the best-fit parameter values are rather large. There is a curve in ({var_epsilon}{sub ij}, {sigma}{sub ij}) space such that parameter values on the curve generate a calculated viscosity in good agreement with measurements for a pure gas or a binary mixture. The various combining rules produce couples of parameters {var_epsilon}{sub ij}, {sigma}{sub ij} that lie close to the curve and therefore generate predicted mixture viscosities in satisfactory agreement with experiment. Although the combining rules were found to underpredict the viscosity in most of the cases, Kong's rule was found to work better than the others, but none of the combining rules consistently yields parameter values near the best-fit values, suggesting that improved rules could be developed.
Date: May 7, 2010
Creator: Bastien, Lucas A.J.; Price, Phillip N. & Brown, Nancy J.
Partner: UNT Libraries Government Documents Department

Comments on "Solubility of Ethyl Maltol in Aqueous Ethanol Mixtures" (Liu, B.-S.; Liu, R.-J.; Hu, Y.-Q.; Hu, Q.-F. J. Chem. Eng. Data 2008, 53, 2712-2714)

Description: This article provides comments on "Solubility of Ethyl Maltol in Aqueous Ethanol Mixtures," published in 2008 in the 'Journal of Chemical and Engineering Data.'
Date: February 17, 2009
Creator: Jouyban, Abolghasem & Acree, William E. (William Eugene)
Partner: UNT College of Arts and Sciences

Aggregation kinetics in a model colloidal suspension

Description: The authors present molecular dynamics simulations of aggregation kinetics in a colloidal suspension modeled as a highly asymmetric binary mixture. Starting from a configuration with largely uncorrelated colloidal particles the system relaxes by coagulation-fragmentation dynamics to a structured state of low-dimensionality clusters with an exponential size distribution. The results show that short range repulsive interactions alone can give rise to so-called cluster phases. For the present model and probably other, more common colloids, the observed clusters appear to be equilibrium phase fluctuations induced by the entropic inter-colloidal attractions.
Date: August 8, 2005
Creator: Bastea, S
Partner: UNT Libraries Government Documents Department

Small-angle and surface scattering from porous and fractal materials.

Description: We review the basic theoretical methods used to treat small-angle scattering from porous materials, treated as general two-phase systems, and also the basic experimental techniques for carrying out such experiments. We discuss the special forms of the scattering when the materials exhibit mass or surface fractal behavior, and review the results of recent experiments on several types of porous media and also SANS experiments probing the phase behavior of binary fluid mixtures or polymer solutions confined in porous materials. Finally, we discuss the analogous technique of off-specular scattering from surfaces and interfaces which is used to study surface roughness of various kinds.
Date: September 18, 1998
Creator: Sinha, S. K.
Partner: UNT Libraries Government Documents Department

Distillation under electric fields

Description: Distillation Is the most common separation process used in the chemical and petroleum industry. Major limitations in the applicability and efficiency of distillation come from thermodynamic equilibria, that is, vapor-liquid equilibria (VLE), and heat and mass transfer rates. In this work, electric fields are used to manipulate the VLE of mixtures. VLE experiments are performed for various binary mixtures in the presence of electric fields on the order of a few kilovolts per centimeter. The results show that the VLE is changed by electric fields, with changes in the separation factor as high as 10% being observed. Batch distillation experiments are also carried out for binary mixtures of 2-propanol and water with and without an applied electric field. Results show enhanced distillation rates and separation efficiency in the presence of an electric field but decreased separation enhancement when the electric current is increased. The latter phenomenon is caused by the formation at the surface of the liquid mixture of microdroplets that are entrained by the vapor. These observations suggest that there should be an electric field strength for each system for which the separation enhancement is maximum.
Date: November 1, 1997
Creator: Shah, V.M.; Blankenship, K.D. & Tsouris, C.
Partner: UNT Libraries Government Documents Department

Gradient-driven diffusion using dual control volume grand canonical molecular dynamics

Description: The dual control volume grand canonical molecular dynamics (DCV-GCMD) method, designed to enable the dynamic simulation of a system with a steady state chemical potential gradient is first briefly reviewed. A new, novel implementation of the method which enables the establishment of a steady state chemical potential gradient in a multicomponent system without having to insert or delete one of the components is then presented and discussed.
Date: June 14, 1998
Creator: Thompson, A.M.; Ford, D.M. & Heffelfinger, G.S.
Partner: UNT Libraries Government Documents Department

Vapor-liquid equilibria for copolymer+solvent systems: Effect of intramolecular repulsion

Description: Role of intramolecular interactions in blend miscibility is well documented for polymer+copolymer mixtures. Some copolymer+polymer mixtures are miscible although their corresponding homopolymers are not miscible; for example, over a range of acrylonitrile content, styrene/acrylonitrile copolymers are miscible with poly(methyl methacrylate) but neither polystyrene nor polyacrylonitrile is miscible with poly(methyl methacrylate). Similarly, over a composition range, butadiene/acrylonitrile copolymers are miscible with poly(vinyl chloride) while none of the binary combinations of the homopolymers [polybutadiene, polyacrylonitrile, and poly(vinyl chloride)] are miscible. This behavior has been attributed to ``intramolecular repulsion`` between unlike copolymer segments. We have observed similar behavior in vapor-liquid equilibria (VLE) of copolymer+solvent systems. We find that acrylonitrile/butadiene copolymers have higher affinity for acetonitrile solvent than do polyacrylonitrile or polybutadiene. We attribute this non-intuitive behavior to ``intramolecular repulsion`` between unlike segments of the copolymer. This repulsive interaction is weakened when acetonitrile molecules are in the vicinity of unlike copolymer segments, favoring copolymer+solvent miscibility. We find similar behavior when acetonitrile is replaced by methyl ethyl ketone. To best knowledge, this effect has not been reported previously for VLE. We have obtained VLE data for mixtures containing a solvent and a copolymer as a function of copolymer composition. It appears that, at a given solvent partial pressure, there may be copolymer composition that yields maximum absorption of the solvent. This highly non-ideal VLE phase behavior may be useful for optimum design of a membrane for a separation process.
Date: March 1, 1995
Creator: Gupta, R.B. & Prausnitz, J.M.
Partner: UNT Libraries Government Documents Department