Aqueous Solutions Of Organic Salts Research Articles

Measurement and modelling of liquid density (298.15 and 313.15 K) and vapour pressure osmometry (313.15 K) for binary aqueous solutions of organic salts

Due to the eco-friendliness of organic salts, they have been gradually replacing other electrolytes in different fields of chemistry. For example, they provide biocompatible salting-out agents for liquid–liquid extractions and earth-abundant materials for flow batteries. Nevertheless, reliable liquid density and vapour pressure data, which are paramount for a proper parameterisation of thermodynamic models, are often hard to find for aqueous solutions of organic salts, delaying the development of these technologies.In this work, the liquid density (ρ) of five binary aqueous solutions of organic salts (disodium tartrate, sodium potassium tartrate, dipotassium tartrate, trisodium citrate and tripotassium citrate) were measured and correlated at 298.15 and 313.15 K and 0.1 MPa. In these assays, second-degree polynomials provided determination coefficients (R2) larger than 0.9982 in the correlation of liquid density with salt molality, for which a very accurate description of this property was accomplished. Moreover, vapour pressure osmometry (VPO) studies were carried out for these solutions at 313.15 K and 0.1 MPa. Then, the obtained osmotic coefficients (ϕ) were successfully modelled using the Extended Pitzer Model of Archer, yielding standard deviations (σϕ) lower than 8.61·10-3. Finally, the mean molal activity coefficients (γ±) and excess Gibbs free energies (GE/RT) of the binary aqueous solutions of organic salts were effectively calculated, with potassium- and tartrate-based salts attaining significantly higher values than the ones composed of sodium and citrate, hinting at a more ideal solution behaviour of the former.

Electro-activation of potassium acetate, potassium citrate and calcium lactate: impact on solution acidity, Redox potential, vibrational properties of Raman spectra and antibacterial activity on E. coli O157:H7 at ambient temperature.

AimsTo study the electro-activation of potassium acetate, potassium citrate and calcium lactate aqueous solutions and to evaluate their antimicrobial effect against E. coli O157:H7 at ambient temperature.Methods and resultsPotassium acetate, potassium citrate and calcium lactate aqueous solutions were electrically excited in the anodic compartment of a four sectional electro-activation reactor. Different properties of the electro-activated solutions were measured such as: solutions acidity (pH and titratable), Redox potential and vibrational properties by Raman spectroscopy. Moreover, the antimicrobial activity of these solutions was evaluated against E. coli O157:H7. The results showed a pH decrease from 7.07 ± 0.08, 7.53 ± 0.12 and 6.18 ± 0.1 down to 2.82 ± 0.1, 2.13 ± 0.09 and 2.26 ± 0.15, after 180 min of electro-activation of potassium acetate, potassium citrate and calcium lactate solution, respectively. These solutions were characterized by high oxidative ORP of +1076 ± 12, +958 ± 11 and +820 ± 14 mV, respectively. Raman scattering analysis of anolytes showed stretching vibrations of the hydrogen bonds with the major changes within the region of 3410–3430 cm−1. These solutions were used against E. coli O157:H7 and the results from antimicrobial assays showed high antibacterial effect with a population reduction of ≥6 log CFU/ml within 5 min of treatment.ConclusionsThis study demonstrated the effectiveness of the electro-activation to confer to aqueous solutions of organic salts of highly reactive properties that differ them from their conjugated commercial acids. The electro-activated solutions demonstrated significant antimicrobial activity against E. coli O157:H7.Significance and impact of studyThis study opens new possibilities to use electro-activated solutions of salts of weak organic acids as food preservatives to develop safe, nutritive and low heat processed foods.

Near Infrared Spectra of Water in Aqueous Solutions of Organic Salts. A Solvation Study of Bu4NBr, , and

The near-infrared spectrum of water at various temperatures and in aqueous solutions of Bu4NBr, [Formula: see text], and [Formula: see text] is studied in the region 0.8–1.2 µ. The spectra are recorded differentially with respect to water by varying the cell lengths as to take into account density changes or the volume occupied by the solutes. A simple analysis of these spectra illustrates the qualitative similarity between the effects of the Bu4N+ ion and that of a temperature decrement on the spectrum of water. On the other hand striking differences are observed in the differential spectra obtained with Bu4NBr and the phenyl substituted: salts. Further differences are exhibited in the relative solute-solvent interactions of [Formula: see text] and [Formula: see text].

Medium effects on hydrogen-1 chemical shift of benzene in micellar and nonmicellar aqueous solutions of organic salts

Medium effects on hydrogen-1 chemical shift of benzene in micellar and nonmicellar aqueous solutions of organic salts