Perturbation of liquid-water structure by ionic substances

Cloud point of aqueous solutions containing oxyethylated methyl dodecanoates: effects of surfactant hydrophilicity, nature of added electrolyte, and water activity

“…The possible formation of complexes between the oxyethylene groups and K + is also to be considered. Beyond the qualitative explanations given above, it should be kept in mind that the situation is certainly more complex, as ions affect in different way the various structures encountered in water, i.e., the four compounds considered by Luu et al [28].…”

Structure of Hydrogels Based on Lyotropic Phases of Cellulose Derivative as Studied by Raman Spectroscopy

“…The OÁÁÁH stretching Raman band for liquid water in the range 2 800-3 800 cm À1 [16,17] consists of four overlapping components with peaks at 3 247 cm À1 , 3 435 cm À1 , 3 535 cm À1 and 3 622 cm À1 . G. E. Walrafen [17] has shown that these components exhibit different temperature dependences.…”

“…[15] A deviation of the integrated intensity ratio, I 3 400 /I 3 200 , from the value characteristic of liquid water (I 3 400 /I 3 200 characteristic of liquid water equal 0.87) [16] can be taken as a measure of changes in the water structure. In hydrogels, the water molecules remaining within the aggregates surrounded by the polymer network, are restricted in their motion.…”

“…Taking into account the above discussion and the literature data, [16] this broad band was deconvoluted into four components. The integrated intensity ratio, I 3 400 /I 3 200 , is here equal to 0.84 and it is in satisfactory agreement with the value of 0.87 reported by Luu et al [16] Figure 7 and 8 show the Raman spectra in the range 2 800-3 800 cm À1 for the isotropic and liquid crystalline phase of HPC in the water solution, respectively. In these systems the water-related bands are overlapped on the lowfrequency side by bands originating from HPC, so deconvolution is more complex and the results should be taken with caution.…”

Differential Scanning Calorimetry Studies of Phospholipid Membranes: The Interdigitated Gel Phase

“…Kosmotropes deplete the solution at the interface and increase the interfacial tension whereas chaotropes accumulate in the interface and decrease surface tension [125]. The changes in the structure of water due to these types of chemicals can be attributed to alterations in the hydrogen bonding network of water [126,127]. Kosmotropic substances are classified as water-structure makers, meaning that they stabilize the structure of bulk water.…”