Aqueous Tetrabutylammonium Bromide Research Articles

Molecular dynamics simulations of interfacial structure, dynamics, and interfacial tension of tetrabutylammonium bromide aqueous solution in the presence of methane and carbon dioxide.

The interfacial behavior of tetrabutylammonium bromide (TBAB) aqueous solutions in the absence of gas and the presence of methane and carbon dioxide gases is studied by molecular dynamics simulations. The aqueous TBAB phase, at concentrations similar to the solid semiclathrate hydrate (1:38 molratio), has a smaller interfacial tension and an increase in the gas molecules adsorbed at the interface compared to that in pure water. Both these factors may contribute to facilitating the uptake of the gases into the solid phase during the process of semiclathrate hydrate formation. At similar gas pressures, CO2 is adsorbed preferentially compared to CH4, giving it a higher surface density, due to the stronger intermolecular interactions of CO2 molecules of the solution at the interface. The increase in relative adsorption of CH4 at the solution surface compared to that in pure water surface is due to the hydrophobic interactions between the n-alkyl chains of the TBA+ cation and methane gas.

Freezing fouling from aqueous solutions of TBAB and TME clathrate hydrates

Crystallisation fouling caused by cooling of aqueous solutions of 10–40 wt% tetrabutylammonium bromide (TBAB) and trimethyloethane (TME) was studied in a two-fingered deposition cell. The clathrates formed semi-solid layers of crystals on the heat transfer surfaces. DSC studies confirmed the existence of different hydration states, particularly for TBAB, which could be described reasonably well by simple models. The enthalpy of fusion measured with DSC was 50–300 J g−1 for aqueous TBAB solutions up to 60 wt% and 150–320 J g−1 for up to 80 wt% TME. Fickian diffusivities estimated using DOSY NMR were 0.5–4 × 10-10 m2 s−1 for TBAB and 2–5 × 10-10 m2 s−1 for TME 10–50 wt% solutions. A quantitative model describing the rate of crystal layer growth based on combined heat and mass transfer control gave good agreement with experimental data and indicated that the fraction of crystals in the matrix approached 40 vol%.

ChemInform Abstract: A One‐Pot Three‐Component Reaction in Aqueous Micellar Medium: An Easy Route to Chromeno[2,3‐b]quinolinedione.

AbstractThe reaction of aldehyde (I) with anilines and dimedone is performed in a reusable aqueous tetrabutylammonium bromide solution to give the title compounds in good to excellent yields.

Measurement of the three-phase (vapour + liquid + solid) equilibrium conditions of semi-clathrates formed from mixtures of CO2, CO and H2

Semi-clathrates were formed in an isochoric equilibrium-cell, from gaseous mixtures of (CO2+H2+CO), in aqueous solutions of tetra-butyl ammonium bromide (TBAB). The experimental temperatures ranged between (282 and 291)K, experimental pressures ranged between (2.6 and 6.6) MPa and the experiments were conducted in aqueous TBAB solutions of wTBAB=(0.05, 0.10, and 0.20). The gas phase composition was analysed, using gas chromatography, and it was observed that the amount of CO2 in the gas phase was reduced. Additionally, the experimental results were compared to the formation conditions required for gas hydrates, that are formed from the same gas mixtures, and it was observed that the pressure required for semi-clathrate formation was significantly less than that required for gas hydrate formation.

Experimental investigation of incipient equilibrium conditions for the formation of semi-clathrate hydrates from quaternary mixtures of (CO 2 + N 2 + TBAB + H 2O)

The three-phase (vapour + liquid + solid) equilibrium conditions for semi-clathrates formed from three mixtures of (CO 2 + N 2), in aqueous solutions of tetra-butyl ammonium bromide (TBAB), were measured in an isochoric reactor. The experiments were conducted at temperatures between (281 and 290) K, at pressures between (1.9 and 5.9) MPa and in aqueous TBAB solutions of w TBAB = (0.05, 0.10, and 0.20). The experimental results obtained in this study were compared with previously obtained results for gas hydrates, formed from the same three mixtures of (CO 2 + N 2) and it was observed that semi-clathrates formed at a substantially lower pressure than did gas hydrates.

Physicochemical investigation on interactions of some amino acids with aqueous tetra-butyl ammonium bromide solution at 298.15 K

Apparent molar volumes, viscosity B-coefficients, and apparent molar isentropic compressibilities of glycine, L-alanine, L-valine and L-leucine in 0.062, 0.125 and 0.256 mol kg−1 aqueous tetra-butyl ammonium bromide (TBAB) solution have been determined at 298.15 K from their experimental density, flow time and sound speed measurements, respectively. The standard partial molar volumes and compressibilities are used to calculate the corresponding volume of transfer at infinite dilution, from water to aqueous TBAB solutions. The linear correlation of partial molar volumes for a homologous series of amino acids has been utilised to calculate the contribution of charged end groups and other alkyl chains of the amino acids to partial molar volumes. The hydration numbers of amino acids have also been determined. Viscosity B-coefficients have been calculated using the Jones–Dole equation. The values of the charged end groups contribution to the viscosity B-coefficients of the amino acids are calculated.

Apparent molar volumes and viscosity B-coefficients of nicotinamide in aqueous tetrabutylammonium bromide solutions at T = (298.15, 308.15, and 318.15) K

Apparent molar volumes ϕ V and viscosity B-coefficients for nicotinamide in (0.00, 0.05, 0.10, and 0.15) mol · dm −3 aqueous tetrabutylammonium bromide (TBAB) solutions have been determined from solution density and viscosity measurements at temperatures over the range (298.15 to 318.15) K as function of concentration of nicotinamide (NA). In the investigated temperature range, the relation: ϕ V ∘ = a 0 + a 1 T + a 2 T 2 , have been used to describe the temperature dependence of the standard partial molar volumes ϕ V ∘ . These results have, in conjunction with the results obtained in pure water, been used to deduce the standard volumes of transfer Δ ϕ V ∘ and viscosity B-coefficients of transfer for nicotinamide from water to aqueous TBAB solutions for rationalizing various interactions in the ternary solutions. The structure making or breaking ability of nicotinamide has been discussed in terms of the sign of ( δ 2 ϕ V ∘ / δ T 2 ) P . An increase in the transfer volume of nicotinamide with increasing TBAB concentration has been explained by Friedman–Krishnan co-sphere model. The activation parameters of viscous flow for the ternary solutions investigated were also determined and discussed by the application of transition state theory.

A vapor pressure method for the simultaneous determination of standard thermodynamic functions of both solutes in a ternary dilute solution

It is shown that from vapor pressure measurements on dilute solutions of ternary mixtures with one nonvolatile component, the standard free energy of transfer (ΔGt0) of both solutes from water to aqueous binary solvents can be determined simultaneously. The method is most useful in the case of volatile components. ΔGt0 values are discussed in particular in the case of the transfer of tetrahydrofuran, acetone, and acetonitrile from water to aqueous tetrabutylammonium bromide and urea solutions and compared to the case of the transfer of nonpolar solutes to the same aqueous solution. In each case, the free energy of transfer from water to an aqueous solution of a nonpolar molecule was negative, and introduction in that molecule of a polar group caused the free energy of transfer to be considerably less negative.

Solubility of helium and methane in aqueous tetrabutylammonium bromide solutions at 25 and 35.deg.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSolubility of helium and methane in aqueous tetrabutylammonium bromide solutions at 25 and 35.deg.Andre Feillolay and Michel LucasCite this: J. Phys. Chem. 1972, 76, 21, 3068–3072Publication Date (Print):October 1, 1972Publication History Published online1 May 2002Published inissue 1 October 1972https://doi.org/10.1021/j100665a028RIGHTS & PERMISSIONSArticle Views81Altmetric-Citations17LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (595 KB) Get e-Alerts