Adsorption of Polar Organic Molecules at Oil/Water and Air/Water Interfaces

1975 ◽  
Vol 53 (6) ◽  
pp. 916-925 ◽  
Author(s):  
Robert Aveyard ◽  
John Chapman
Keyword(s):  
Dicarboxylic Acid ◽  
Water Surface ◽  
Equations Of State ◽  
Good Description ◽  
Dicarboxylic Acids ◽  
Solution Model ◽  
Two Dimensional ◽  
Free Energies ◽  
Dimensional Solution ◽  
Oil Water

A study has been made of the adsorption of several esters of dicarboxylic acids both at the alkane/water and the air/water interface. The adsorption of n-butanol and n-heptanol at the air/water surface has also been investigated. The surface pressure (π) – surface area (A) isotherms are compared for the various films, and standard free energies of adsorption have been determined.Attempts have been made to fit the π, A isotherms using surface equations of state based on the models of both a two-dimensional gas and a two-dimensional solution. The solution model has proved reasonably successful for fairly dilute films at the air/water surface. At higher coverages, an equation derived by Smith for liquid expanded monolayers gives a moderately good description of films of heptanol on water. A simple application of the solution model to adsorbed monolayers at the liquid/liquid interface met with little success. It is found however that two-dimensional gas equations describe such systems surprisingly well for fairly low surface concentrations.As part of the study, the activity coefficients of methyl dodecanoate, and the diethyl esters of pentan-1,5-dicarboxylic acid and decan-1,10-dicarboxylic acid, all in dilute solution in n-octane at 30 °C, have been determined.

The adsorption of tri-n-butylphosphate at the n-dodecane–water interface

1979 ◽  
Vol 57 (10) ◽  
pp. 1218-1223 ◽  
Author(s):  
Norman H. Sagert ◽  
Woon Lee ◽  
Michael J. Quinn
Keyword(s):  
Mole Fraction ◽  
Model Equation ◽  
Equations Of State ◽  
Water Interface ◽  
Two Dimensional ◽  
Free Energies ◽  
Dimensional Solution ◽  
Simple Version ◽  
Enthalpy Of Adsorption ◽  
Gas Laws

The adsorption of tri-n-butylphosphate (TBP) from n-dodecane to the n-dodecane–water interface has been studied as a function of TBP mole fraction up to 2.7 × 10−4 in the n-dodecane, and as a function of temperature from 293.15 K to 308.15 K. Free energies of adsorption were calculated from the results at low TBP mole fractions, where the surface pressures were linear with mole fraction. They were in the range −36.1 to −35.6 kJ/mol. The enthalpy of adsorption, determined from the variation of the free energies of adsorption with temperature, was −45.4 kJ/mol.Several equations of state based on two-dimensional gas laws were applied to the results. The Schofield–Rideal equation described the results adequately but the simpler Volmer equation was inadequate especially at lower temperatures. Deviations from the Volmer equation were in the direction of higher surface pressure. A simple version of the two-dimensional solution model equation of state was not helpful.

scholarly journals Two-dimensional metal-organic frameworks containing linear dicarboxylates

2006 ◽  
Vol 62 (5) ◽  
pp. 808-814 ◽  
Author(s):  
Samuel M. Hawxwell ◽  
Harry Adams ◽  
Lee Brammer
Keyword(s):  
Dicarboxylic Acid ◽  
Solvothermal Synthesis ◽  
Interplanar Spacing ◽  
Metal Organic Frameworks ◽  
Dicarboxylic Acids ◽  
Two Dimensional ◽  
Secondary Building Units ◽  
Metal Organic ◽  
Gas Molecules ◽  
Solvent Molecules

The solvothermal synthesis of four two-dimensional metal-organic frameworks containing linear dicarboxylic acids as ligands for ZnII centres is described. Zn(BDC)(DMF) [(1) where BDC = benzene-1,4-dicarboxylic acid; DMF = N,N-dimethylformamide] adopts a common paddlewheel motif leading to a 44 grid network, whereas Zn3(BDC)3(EtOH)2 (2), Zn3(BDC)3(H2O)2·4DMF (3) and Zn3(BPDC)3(DMF)2·4DMF (4) each form networks with the relatively uncommon 36 topology based upon Zn3(O2CR)6 secondary building units. All contain coordinated solvent molecules, namely DMF [(1) and (4)], ethanol (2) or H2O (3). Comparison of structures (2) and (3) illustrates a clay-like flexibility in interplanar spacing which sheds light on the ability of the Zn3(BDC)3 framework to undergo desolvation and uptake of small solvent and gas molecules.

The adsorption of lower trialkylphosphates at the dodecane – water interface

1980 ◽  
Vol 58 (24) ◽  
pp. 2789-2795 ◽  
Author(s):  
Norman H. Sagert ◽  
Woon Lee
Keyword(s):  
Equation Of State ◽  
Chain Length ◽  
Water Interface ◽  
Two Dimensional ◽  
Free Energies ◽  
Dimensional Solution ◽  
Interfacial Tensions ◽  
Enthalpy Of Adsorption ◽  
Solution Models ◽  
Methylene Group

The adsorption of tripropylphosphate, triethylphosphate, and trimethylphosphate at the dodecane–water interface has been studied at temperatures from 293 to 313 K. Standard free energies of adsorption were obtained from the lowering of interfacial tensions in the low (< 10−4) solute mole fraction region. Standard enthalpies and entropies of adsorption were then obtained from the temperature variation of the standard free energies of adsorption.Standard free energies of adsorption from dodecane showed little variation with solute chain length, with the exception of trimethylphosphate. On the other hand, free energies of adsorption from water decreased by 3.45 kJ/mol for each methylene group added, again with the exception of trimethylphosphate. Enthalpies of adsorption increased linearly with increasing solute chain length for adsorption from either phase. For each methylene group added, the enthalpy of adsorption from dodecane increased by 2.9 kJ/mol, while that from water increased by 2.4 kJ/mol.Results for tripropylphosphate adsorption and for triethylphosphate adsorption at higher temperatures could be adequately described by the Schofield–Rideal equation of state, but not by simple two-dimensional solution models. Results for trimethylphosphate adsorption and for triethylphosphate adsorption at lower temperatures could not be fitted adequately by either type of equation of state.

IR and 13C, 17O, and 119Sn NMR spectra of some bis(1-butyl)tin(IV) carboxylates of dicarboxylic acids

1991 ◽  
Vol 56 (9) ◽  
pp. 1908-1915 ◽  
Author(s):  
Jaroslav Holeček ◽  
Antonín Lyčka ◽  
Milan Nádvorník ◽  
Karel Handlíř
Keyword(s):  
Infrared Spectroscopy ◽  
Nmr Spectroscopy ◽  
Dicarboxylic Acid ◽  
Nmr Spectra ◽  
Dicarboxylic Acids ◽  
119Sn Nmr ◽  
Carboxylic Groups ◽  
Cyclic Oligomers ◽  
The Media ◽  
Oxygen Atoms

Infrared spectroscopy and multinuclear (13C, 17O, and 119Sn NMR spectroscopy have been used to study the structure of bis(1-butyl)tin(IV) carboxylates of dicarboxylic acids (1-C4H9)2. Sn(X(COO)2), where X = (CH2)n (n = 0-8), CH=CH (cis and trans) and C6H4 (ortho and para).The crystalline compounds are formed by linear or cyclic oligomers or polymers whose basic building units represent a grouping composed of the central tin atom substituted by two 1-butyl groups and coordinated with both oxygen atoms of two anisobidentate carboxylic groups derived from different molecules of a dicarboxylic acid. The environment of the tin atom has a shape of a trapezoidal bipyramid. When dissolvet in non-coordinating solvents, the compounds retain the oligomeric character with unchanged structure of environment of the central tin atom. In the media of coordinating solvents the bis(1-butyl)tin(IV) carboxylates of dicarboxylic acids form complexes whose central hexacoordinated tin atom binds two molecules of the solvent trough their donor atoms. Carboxylic groups form monodenate linkages in these complexes.

Separation of Enantiomers and Racemate Formation in Two-Dimensional Crystals at the Water Surface from Racemic α-Amino Acid Amphiphiles:  Design and Structure

1997 ◽  
Vol 119 (5) ◽  
pp. 933-942 ◽  
Author(s):  
Isabelle Weissbuch ◽  
Maria Berfeld ◽  
Wim Bouwman ◽  
Kristian Kjaer ◽  
Jens Als-Nielsen ◽  
...  
Keyword(s):  
Amino Acid ◽  
Water Surface ◽  
Two Dimensional ◽  
Separation Of Enantiomers
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