Hydratation und hydrophobe Wechselwirkung der Ionen in Polyelektrolyten mit einer Folgerung bezüglich der biologischen Membranen

1969 ◽  
Vol 24 (4) ◽  
pp. 375-377 ◽  
Author(s):  
G. Zundel ◽  
A. Murr
Keyword(s):  
Sulfonic Acid ◽  
Pure Water ◽  
Water Structure ◽  
Water Molecules ◽  
Pure Liquid ◽  
Ammonium Ions ◽  
Alkali Ions ◽  
Stretching Vibration ◽  
Polystyrene Sulfonic Acid ◽  
Alkyl Ammonium

The OH stretching vibration of the water molecules in membranes of salts of polystyrene sulfonic acid is investigated by IR spectroscopy. In the series of the alkali ions anomalous behaviour of the position of this band is to be seen. If one compares the position of this band with the corresponding one in pure liquid water this anomality is to be understood like follows: From Li⊕ to Cs⊕ in a progressing degree the molecules of water are not still attached between cation and neighboring anions, but they are present as network of „pure“ water structure cross-linked by hydrogen bonds in the neighbourhood of the ions. A similar situation but to an even greater extend is found in the presence of alkyl ammonium ions. These ions are interacting more strongly with the - SO3⊝ ions. The reasons for this are given. By these results it is understandable that in biological membranes the alkyl ammonium group of the lecithins and sphingomyelines - as postulated by FINEAN - are turned away the surface inwardly in the membran. In the end the different hydration behaviour of the Na⊕ and K⊕ ions is discussed.

The mobility of alkali ions in gases III. The mobility of alkali ions in water vapour

1939 ◽  
Vol 172 (948) ◽  
pp. 51-54 ◽  
Keyword(s):  
Water Vapour ◽  
Infinite Dilution ◽  
Pure Water ◽  
Atomic Weight ◽  
Alkali Atom ◽  
Water Molecules ◽  
Degree Of Hydration ◽  
Alkali Ions ◽  
Alkali Ion

It is known that in electrolytes at infinite dilution the mobility of an alkali ion increases with its mass and this has been attributed by some to a decrease in its degree of hydration as the size of the alkali atom increases. In Part I evidence was obtained, at least in helium and neon, that the average number of water molecules which are attached to an alkali ion when water is present as an impurity also decreases as the atomic weight of the ion increases. As a natural corollary to this work a determination of the mobility of the alkali ions in pure water vapour has been undertaken and is here described. The method and apparatus of Part I was used. The nature of the ion from the source was first verified by running it in a pure gas which was then pumped off and water vapour introduced. The results are shown in fig. 1, where the mobility of the ion is plotted with E/p . For the sake of clearness the results for Rb + are excluded from the graph except at low values of E/p . The remainder of the Rb + graph follows more or less that for Na + .

Excess partial molar enthalpies of 2-butoxyethanol and water in 2-butoxyethanol–water mixtures

1989 ◽  
Vol 67 (4) ◽  
pp. 671-676 ◽  
Author(s):  
William Siu ◽  
Yoshikata Koga
Keyword(s):  
Long Range ◽  
Water Clusters ◽  
Pure Water ◽  
Threshold Value ◽  
Water Molecules ◽  
Pure Liquid ◽  
Entire Concentration Range ◽  
Solute Interaction ◽  
Excess Partial Molar Enthalpy ◽  
Partial Molar Enthalpies

Excess partial molar enthalpies of 2-butoxyethanol (BE) and water, [Formula: see text](I = BE or H2O), were measured from 25 to 35 °C in the entire concentration range. The results indicated that there are three concentration regions bounded at about xB = 0.02 and xB = 0.5, xB being the mole fraction of BE. In each region, the concentration and temperature dependence of [Formula: see text] (I = BE or H2O), is distinctively different from those in the other regions, and appears to support the following views: In the water-rich region, xB < 0.02, BE molecules cause an enhancement in the structure of water, and this effect spans a long range via a structurally enhanced network of water. The solute–solute (BE–BE) interaction is repulsive and of a long range character in terms of enthalpy. As xB increases, the repulsive solute–solute interaction becomes stronger sharply to the threshold value, xB ≈ 0.017, whereupon the mode of such mixing no longer becomes possible. In the intermediate range, 0.02 < χB < 0.5, a new scheme whereby BE molecules tend to associate is predominant. Two clathrate-like aggregates of the types h[BE(H2O)k] with k = 55 and 4 may exist together with BE clusters (BE)n In the third region, 0.5 < xB, BE molecules are exactly in the same environment as in pure liquid, while water molecules are almost in the same environment as in pure water. The solution consists of BE and water clusters. Keywords: excess partial molar enthalpy, 2-butoxyethanol–water.

Nanoporous polystyrene sulfonic acid blended membranes

2020 ◽  
Author(s):  
Adam Bruce Ung ◽  
G. K. Surya Prakash ◽  
Thieo E. Hogen-Esch
Keyword(s):  
Sulfonic Acid ◽  
Polystyrene Sulfonic Acid

Nanoporous polystyrene sulfonic acid blended membranes

2020 ◽  
Author(s):  
Adam Bruce Ung ◽  
G. K. Surya Prakash ◽  
Thieo E. Hogen-Esch ◽  
Adam Bruce Ung
Keyword(s):  
Sulfonic Acid ◽  
Polystyrene Sulfonic Acid

scholarly journals Behavior and properties of water in silicate melts under deep mantle conditions

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bijaya B. Karki ◽  
Dipta B. Ghosh ◽  
Shun-ichiro Karato
Keyword(s):  
Electrical Conductivity ◽  
Molar Volume ◽  
Water Solution ◽  
Pure Water ◽  
Electrical Conductance ◽  
Water Structure ◽  
Bulk Water ◽  
Silicate Melts ◽  
Pressure Regime ◽  
Low Pressures

AbstractWater (H2O) as one of the most abundant fluids present in Earth plays crucial role in the generation and transport of magmas in the interior. Though hydrous silicate melts have been studied extensively, the experimental data are confined to relatively low pressures and the computational results are still rare. Moreover, these studies imply large differences in the way water influences the physical properties of silicate magmas, such as density and electrical conductivity. Here, we investigate the equation of state, speciation, and transport properties of water dissolved in Mg1−xFexSiO3 and Mg2(1−x)Fe2xSiO4 melts (for x = 0 and 0.25) as well as in its bulk (pure) fluid state over the entire mantle pressure regime at 2000–4000 K using first-principles molecular dynamics. The simulation results allow us to constrain the partial molar volume of the water component in melts along with the molar volume of pure water. The predicted volume of silicate melt + water solution is negative at low pressures and becomes almost zero above 15 GPa. Consequently, the hydrous component tends to lower the melt density to similar extent over much of the mantle pressure regime irrespective of composition. Our results also show that hydrogen diffuses fast in silicate melts and enhances the melt electrical conductivity in a way that differs from electrical conduction in the bulk water. The speciation of the water component varies considerably from the bulk water structure as well. Water is dissolved in melts mostly as hydroxyls at low pressure and as –O–H–O–, –O–H–O–H– and other extended species with increasing pressure. On the other hand, the pure water behaves as a molecular fluid below 15 GPa, gradually becoming a dissociated fluid with further compression. On the basis of modeled density and conductivity results, we suggest that partial melts containing a few percent of water may be gravitationally trapped both above and below the upper mantle-transition region. Moreover, such hydrous melts can give rise to detectable electrical conductance by means of electromagnetic sounding observations.

CONDUCTANCES OF LITHIUM NITRATE SOLUTIONS IN ETHYL ALCOHOL AND ETHYL ALCOHOL - WATER MIXTURES AT 25.0 °C.

1956 ◽  
Vol 34 (9) ◽  
pp. 1232-1242 ◽  
Author(s):  
A. N. Campbell ◽  
G. H. Debus
Keyword(s):  
No Value ◽  
Ethyl Alcohol ◽  
Pure Water ◽  
Lithium Ion ◽  
Water Molecules ◽  
Lithium Nitrate ◽  
Absolute Alcohol ◽  
Pure Alcohol ◽  
Alcohol Water ◽  
Nitrate Solutions

The conductances of solutions of lithium nitrate in 30, 70, and 100 weight per cent ethyl alcohol have been determined at concentrations ranging from 0.01 molar up to saturation, at 25 °C. The densities and viscosities of these solutions have also been determined. The data have been compared with the calculated conductances obtained from the Wishaw–Stokes equation. The agreement is fairly good up to, say, 2 M, for all solvents except absolute alcohol. In the latter solvent there is no value of å, the distance of closest approach, which will give consistent values of the equivalent conductance. In passing from pure water to pure alcohol, the value of å increases progressively and this we attribute to a change in the solvation of the lithium ion from water molecules to alcohol molecules. Some further calculations incline us to the view that the nitrate ion, as well as the lithium ion, is solvated to some extent, at least in alcohol.

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