Chemical equilibrium of esterification in AcOH-EtOH-H2O-EtOAc system at 293.15 K

New experimental data on the chemical equilibrium of esterification in an acetic acid-ethanol-water-ethyl acetate system at 293.15 K and atmospheric pressure are presented.     

Mobility of small molecules in membrane materials based on copolyimide P84

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Pervaporation selectivity as a function of pressure and sorption properties of a polymeric film membrane

Results obtained in an experimental study of the pervaporation of binary solutions with a cellulose hydrate (cellophane) nonporous film membrane are discussed. A primary attention is given to the sorption and the effect of the residual pressure of the permeate on the separation characteristics.     

Chemical equilibrium in a heterogeneous fluid phase system: thermodynamic regularities and topology of phase diagrams

Singularities of the systems with simultaneous phase and chemical equilibria were examined. The thermodynamic regularities were revealed and topology of phase diagrams was presented for multicomponent heterogeneous systems including two or several equilibrium liquid phases (solution layering). The thermodynamic conditions for displacement of phase and chemical equilibrium are considered.     

Kinetics of Ruddlesden-Popper Phase Formation: III. Mechanism of Gd2SrAl2O7 Formation

Studies on phase formation in the system Gd₂O₃-SrO-Al₂O₃ in the range 900-1530°C showed that the synthesis of Gd₂SrAl₂O₇ occur by a mechanism differing from the mechanism of Ln₂SrAl₂O₇ formation (Ln = La, Nd, Sm), and the limiting stage is reaction between Gd₂O₃ and SrAl₂O₄.     

Chemical Equilibrium for the Reacting System Acetic Acid–Ethanol–Ethyl Acetate–Water at 303.15 K, 313.15 K and 323.15 K

The chemical equilibrium (CE) for the quaternary reacting system ethanol–acetic acid–ethyl acetate–water was studied at 303.15, 313.15 and 323.15 K and atmospheric pressure. The CE compositions were determined by gas chromatography and nuclear magnetic resonance analytical methods. The thermodynamic constants of CE at 303.15, 313.15 and 323.15 K were calculated based on the obtained experimental data with the use of the NRTL model.     

Kinetics of Formation of Ruddlesden-Popper Phases: I. Mechanism of La2SrAl2O7 Formation

Phase formation in the La₂O₃-SrO-Al₂O₃ system was studied. Formation of the perovskite LaAlO₃ structure and the perovskite-like LaSrAlO₄ and La₂SrAl₂O₇ layered structures in solid-phase chemical reactions is activated only after reaching certain critical temperatures which correlate with the temperatures of of the transition of intergranular formations to the liquid-like state (melting points of two-dimensional nonautonomous phases).     

Solubility in the system constituted by acetic acid, n-propanol, water, and n-propyl acetate

Experimental data on the solubility in the system constituted by acetic acid, n-propanol, water, and n-propyl acetate at 313.15 K are presented. The position of the critical curve for the liquid-liquid equilibrium, including that of the critical points on the chemical equilibrium surface, is discussed.     

Effects of surfactants on the formation and the stability of interfacial nanobubbles

Contamination has previously been invoked to explain the flat shape and the long lifetimes of interfacial nanobubbles (INBs). In this study, the effects of surfactants on the formation and the stability of INBs were investigated when surfactants were added to the system before, during, and after the standard solvent exchange procedure (SSEP) for the formation of INBs. The solutions of sodium dodecyl sulfate (SDS) above critical micelle concentration were found to have little effect on the bubble stability. Likewise, cleaning of the substrate with a surfactant solution had little effect. In contrast, addition of a water-insoluble surfactant during the formation dramatically reduced the INBs. Finally, repeated application of SSEP to surfactant-coated substrates progressively rinsed the surfactant off the system. Thus, we found no evidence to support the hypothesis that (1) INBs are stabilized by a layer of insoluble organic contaminant or that (2) SSEP introduces surface-active materials to the system that could stabilize INBs.