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Solubility Behavior (solubility + behavior)
Selected AbstractsAntimony-Doped Tin Oxide Nanocrystals: Synthesis and Solubility Behavior in Organic SolventsCHEMPHYSCHEM, Issue 5 2009Rafael O. da Silva Abstract The right mix: SnO2:Sb nanocrystals (NCs) can be solubilized into organic solvents with a suitable solvent/surfactant combination to achieve a stable colloid (see picture). A single synthesis route and different solvent/amphiphilic molecule pairs are used to obtain soluble NC colloids, instead of requiring several syntheses to obtain soluble NCs in different solvents. This work focuses on the nonaqueous synthesis of antimony-doped tin oxide nanocrystals in the size range of 2,6 nm and the investigation of their solubility in organic solvents (CHCl3 and THF) in the presence of amphiphilic molecules (oleic acid and oleylamine). To unravel the underlying processes, a set of molecular dynamics simulations is performed involving the compatibility of oleic acid and oleylamine in mixtures with both CHCl3 and THF. The results show that the method is useful for obtaining the desired oxide, and that the interaction between amphiphilic molecules and solvents can be predicted by molecular dynamics simulations with very good qualitative agreement. [source] Solid,liquid equilibrium of substrates and products of the enzymatic synthesis of ampicillinAICHE JOURNAL, Issue 6 2010Mônica Santana Abstract The solid,liquid equilibrium of precursors and products of the enzymatic synthesis of ampicillin (AMP) [6-aminopencillanic acid (6-APA) and D(,)phenylglycine (PG)] was investigated at different temperatures (283,298 K) and pHs (5.5,7.5). Solubility data were obtained using an analytical methodology. Equilibrium dissociation constants were experimentally measured at several temperatures for AMP, 6-APA, PG, and D(,)phenylglycine methyl ester. A model based on the simplified perturbed hard sphere theory proposed by Khoshkbarchi and Vera (Ind Eng Chem Res. 1996;35:4319-4327) was fitted against solubility data. The model could describe the water solubility behavior for AMP and PG as function of pH and temperature, but a bias was observed when fitting the model to the solubility of 6-APA. © 2009 American Institute of Chemical Engineers AIChE J, 2010 [source] Method for predicting solubilities of solids in mixed solventsAICHE JOURNAL, Issue 5 2009Martin E. Ellegaard Abstract A method is presented for predicting solubilities of solid solutes in mixed solvents, based on excess Henry's law constants. The basis is statistical mechanical fluctuation solution theory for composition derivatives of solute/solvent infinite dilution activity coefficients. Suitable approximations are made for a single parameter characterizing solute/solvent interactions. Comparisons with available data show that the method is successful in describing a variety of observed mixed solvent solubility behavior, including nearly ideal systems with small excess solubilities, systems with solute-independent excess solubilities, and systems deviating from these simple rules. Successful predictions for new solvent mixtures can be made using limited data from other mixtures. © 2009 American Institute of Chemical Engineers AIChE J, 2009 [source] Poly[1-(trimethylgermyl)-1-propyne] and poly[1-(trimethylsilyl)-1-propyne] with various geometries: Their synthesis and propertiesJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 14 2003V. S. Khotimsky Abstract The polymerization of 1,2-disubstituted acetylenes [1-(trimethylgermyl)-1-propyne and 1-(trimethylsilyl)-1-propyne] initiated by Nb- and Ta-based catalytic systems was studied within a wide temperature range (,10 to +80 °C) with solvents (cyclohexane, CCl4, toluene, anisol, and n -chlorobutane) with variable dielectric constants (2.023,7.390). Conditions ensuring the synthesis of poly[1-(trimethylsilyl)-1-propyne] (PTMSP) containing 20,80% cis units and poly[1-(trimethylgermyl)-1-propyne] (PTMGP) containing 3,65% cis units were determined. The PTMSP and PTMGP samples were amorphous, exhibited a two-phase structure characterized by the presence of less ordered regions and regions with an enhanced level of ordering, and differed in solubility. A correlation was found between the cis/trans ratio and the morphology, the geometrical density of PTMSP and PTMGP films, and the gas permeability of the polymers. The gas permeability and solubility behavior of PTMSP and PTMGP were examined in terms of the molecular characteristics of the polymer samples (the thermodynamic Kuhn segment and the Kerr electrooptic effect). It was demonstrated that the gas permeability, as well as the solubility of the polymers, was defined by their supramolecular ordering, which depended on the lengths of continuous sequences composed of units of analogous microstructures and on the flexibility of macrochains. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2133,2155, 2003 [source] Effect of sulfonic group on solubility parameters and solubility behavior of poly(2,6-dimethyl-1,4-phenylene oxide)POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 1 2007Chunli Gong Abstract An investigation on the effect of sulfonic group on solubility parameters and solubility behavior of poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) is presented. Sulfonated PPO (SPPO) was prepared using chlorosulfonic acid as a sulfonating agent. The structure of SPPO was confirmed by FT-IR, and the ion exchange capacity (IEC) of SPPO was accurately determined by conductometric titration and 1H-NMR. The three-dimensional solubility parameters of SPPO defined by Hansen were estimated by group contribution, and this approach was used to obtain the three coordinates of a solubility parameter in terms of: a dispersion part ,d, a polar part ,p and a hydrogen bonding part ,h. The theoretical predications of solubility behavior were characterized using "soluble sphere" in three-dimensional space. The estimated results were in accordance with the solubility experiments in different solvents. Copyright © 2006 John Wiley & Sons, Ltd. [source] Influence of [Ba + Ca]/[Ti + Zr] Ratio on the Interfacial Property of (Ba,Ca)(Ti,Zr)O3 (BCTZ) Powders in an Aqueous MediumJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 6 2003Jaeho Lee We report findings on the electrokinetic and solubility behaviors of (Ba,Ca)(Ti,Zr)O3 (BCTZ) powders having three different [Ba + Ca]/[Ti + Zr] ratios: 0.995, 1.000, and 1.005. Electrokinetic and solubility properties of BCTZ powders in aqueous media are phenomenologically similar to BaTiO3. Ba and Ca ions, occupying primarily A-sites on the perovskite lattice, dissolve during acid titration, which results in surface depletion of A-site cations in the surface region of BCTZ particles. The electrokinetics of colloidal BCTZ powders reflects changes in the surface chemistry that occur as a result of dissolution and adsorption/reprecipitation of surface ions. An increase in [Ba + Ca]/[Ti + Zr] ratio results in an increase in the dynamic mobility at all pH values, an increase in the titration hysteresis, and an increase in the isoelectric pH. Each of these effects can be attributed to Ba and Ca in the near-surface region of BCTZ. [source] | |||||||||||||