Thermodinamic analysis of phase equilibria, volumetric anda transport properties of multicomponent systems of ionic liquids and organic solvents

U ovoj doktorskoj disertaciji eksperimentalno su određene rastvorljivosti binarnih i pseudo - binarnih smeša, odnosno termodinamičke ravnoteže tečno - tečno i čvrsto - tečno, kao i uticaj dodavanja različitih ko - rastvarača na pomeranje fazne ravnoteže, na atmosferskom pritisku i u temperaturnom intervalu od 288.15 K do 371.15 K . Svi dobijeni rezultati prikazani su grafički, formiranjem faznih dijagrama temperatura - sastav. Izvršena su merenja ravnotežnih, volumetrijskih i transportnih svojstava višekomponentnih sistema ekoloških rastvarača: jonskih tečnosti, polimera i alkohola sa organskim rastvaračima. Eksperimentalno su određivana termodinamička svojstva čistih komponenata i njihovih smeša u temperaturnom opsegu od T=(288.15-333.15) K i na atmosferskom pritisku. Eksperimentalno su merene gustine, indeksi refrakcije i viskoznosti ekoloških rastvarača u smeši sa industrijskim zagađivačima. Iz eksperimentalnih podataka izračunate su dopunske molarne zapremine E V , promena viskoznosti Δη, promena indeksa refrakcije nD kao i dopunske termodinamičke veličine: E G dopunska Gibsova energija aktivacije viskoznog toka, E S dopunska enrtopija i E H dopunska entalpija, koeficijent izobarske ekspanzije α, dopunski koeficijent izobarske ekspanzije αE. Izračunate termodinamičke veličine su korišćene za analizu specifičnih molekulskih interakcija i efekata mešanja između komponenata smeša, uzimajući u obzir geometrijska pakovanja između komponenata i uticaj temperature. Ravnotežni podaci čvrsto - tečno za sva četiri binarna sistema su uspešno korelisani NRTL modelom sa dva različita temperaturno zavisna parametra, 12 g i 21 g Fourier-ova transformaciona infracrvena (FT-IR) spektroskopija binarnih smeša nikotina sa alkoholima i odgovarajućih čistih komponenata izvedena je na 298.15 K. u cilju pojašnjenja molekulske strukture, intra - i inter - molekulskih interakcija u rastvorima. Modelovanje viskoziteta rađeno je sa dva modela: modelima doprinosa grupa UNIFAC-VISCO i ASOG-VISCO modelima, i korelativnim McAllister dvoparametarski three-body i troparametarski four-body modelima...In this doctoral dissertation, binary and pesudobinary mixtures were experimentally determined. Those were thermodynamic equilibrium liquid - liquid and solid - liquid, as well as the influence of adding different co - solvents on the phase balance displacement at atmospheric pressure and in the temperature range from 288.15 K to 371.15 K. All obtained results are presented graphically by forming phase diagrams of temperature - content. Measurements of equilibrium, volumetric and transport properties of multicomponent ecological solvent systems were performed: ionic liquids, polymers and alcohols with organic solvents. The thermodynamic properties of pure components and their mixtures in the temperature range from T = (288.15-333.15) K and at atmospheric pressure were determined experimentally. Density, refractive indices and viscosity of organic solvents in mixtures with industrial pollutants were experimentally measured. Complementary molar volumes E V , change in viscosity Δη, change in refractive index nD , as well as additional thermodynamic sizes were computed from the experimental data: E G additional Gibbs viscosity current activation energy, E S supplemental entropy and E H supplemental enthalpy, coefficient of isobar expansion α, supplementary iso-expansion expansion ekspanzije αE. The calculated thermodynamic quantities were used to analyze specific molecular interactions and mixing effects between the components of the mixture, taking into account the geometric packings between the components and the effect of the temperature. The equilibrium data firmly-fluently for all four binary systems were successfully correlated with the NRTL model with two different temperature-dependent parameters 12 g and 21 g Fourier's transformation infrared (FT-IR) spectroscopy of binary mixtures of nicotine with alcohols and corresponding pure components was performed at 298.15 K in order to clarify molecular structure and intra - and intermolecular interactions in solutions..

Excess molar volumes and viscosity behaviour of binary mixtures of aniline/or N, N-dimethylaniline with imidazolium ionic liquids having triflate or bistriflamide anion

In this study, densities and viscosities of four binary systems {aniline / N, N-dimethylaniline+1-butyl-3-methylimidazolium triflate ([bmim][OTf])} and {aniline/N, N-dimethylaniline + 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([bmim][NTf2])} were measured at atmospheric pressure and within the temperature range T = (288.15 to 333.15) K. Excess molar volumes VE, viscosity deviations Δη and excess molar Gibbs energies of activation of viscous flow ∆G∗E were calculated and the results were fitted to a Redlich-Kister polynomial equation. Also, enthalpic and entropic parts of the ∆G∗E function were determined, at the same composition, for three studied systems that exhibit complete miscibility, since {aniline + [bmim][OTf]} is a partially miscible system. Considering the calculated thermodynamic properties, molecular interactions in the investigated binary systems were analysed and are discussed

Thermodynamic characterization of binary mixtures of poly(propylene glycol) 425 with toluene and o-, m- and p-xylenes

Density ρ viscosity η and refractive index nD have been experimentally measured for four binary mixtures of poly(propylene glycol) of average molecular weight 425 + toluene/o-xylene/m-xylene/p-xylene over the temperature range T = (293.15–333.15) K with temperature step 5 K and at atmospheric pressure. From the experimental data excess molar volumes VE, deviations in refractive index ΔnD, viscosity deviations Δη and excess Gibbs free energy of activation of viscous flow ΔG*E were calculated and fitted with Redlich-Kister polynomial in order to analyze non-ideal behavior of the studied mixtures. From ΔG* values excess entropy ΔS*E and excess enthalpy of activation of viscous flow ΔH*E were also calculated. It was shown that specific weak, but numerous, attractive interactions and entropic effect, due to difference in size of the pure component molecules, are responsible for volumetric and viscosity behaviour of the studied systems. The viscosities of the studied systems were predicted with the UNIFAC-VISCO and ASOG-VISCO models and correlated with the McAllister equation

Još o toksičnosti kadmija - s posebnim osvrtom na nastanak oksidacijskoga stresa i na interakcije s cinkom i magnezijem

Discovered in late 1817, cadmium is currently one of the most important occupational and environmental pollutants. It is associated with renal, neurological, skeletal and other toxic effects, including reproductive toxicity, genotoxicity, and carcinogenicity. There is still much to find out about its mechanisms of action, biomarkers of critical effects, and ways to reduce health risks. At present, there is no clinically efficient agent to treat cadmium poisoning due to predominantly intracellular location of cadmium ions. This article gives a brief review of cadmium-induced oxidative stress and its interactions with essential elements zinc and magnesium as relevant mechanisms of cadmium toxicity. It draws on available literature data and our own results, which indicate that dietary supplementation of either essential element has beneficial effect under condition of cadmium exposure. We have also tackled the reasons why magnesium addition prevails over zinc and discussed the protective role of magnesium during cadmium exposure. These findings could help to solve the problem of prophylaxis and therapy of increased cadmium body burden.Iako je otkriven tek 1817. godine, kadmij je trenutačno jedan od najvažnijih onečišćivača životne i radne sredine. Štetno djeluje na bubrege, živčani sustav, kosti, reproduktivni sistem, a ima i genotoksične i karcinogene efekte. Nužna su dalja istraživanja vezana za mehanizme njegove toksičnosti, biomarkere efekata, kao i načine smanjenja rizika za zdravlje. Osim toga, do danas nije otkriven agens efikasan u terapiji trovanja kadmijem s obzirom na to da je kadmij intracelularni kation. U ovom radu dan je sažet pregled važnih mehanizama toksičnosti kadmija, kao što su nastanak oksidativnog stresa i interakcije s esencijalnim elementima, cinkom i magnezijem, na osnovi dostupnih literaturnih podataka, kao i naših ispitivanja koja upućuju na to da povećani unos navedenih esencijalnih elemenata pokazuje pozitivne efekte pri ekspoziciji kadmiju. Obrazložena je prednost suplementacije magnezijem pred suplementacijom cinkom i razmatrana preventivna uloga magnezija pri intoksikaciji kadmijem. Ovi su rezultati doprinos rješavanju problema profi lakse i terapije trovanja kadmijem

Thermodinamic analysis of phase equilibria, volumetric anda transport properties of multicomponent systems of ionic liquids and organic solvents

U ovoj doktorskoj disertaciji eksperimentalno su određene rastvorljivosti binarnih i pseudo - binarnih smeša, odnosno termodinamičke ravnoteže tečno - tečno i čvrsto - tečno, kao i uticaj dodavanja različitih ko - rastvarača na pomeranje fazne ravnoteže, na atmosferskom pritisku i u temperaturnom intervalu od 288.15 K do 371.15 K . Svi dobijeni rezultati prikazani su grafički, formiranjem faznih dijagrama temperatura - sastav. Izvršena su merenja ravnotežnih, volumetrijskih i transportnih svojstava višekomponentnih sistema ekoloških rastvarača: jonskih tečnosti, polimera i alkohola sa organskim rastvaračima. Eksperimentalno su određivana termodinamička svojstva čistih komponenata i njihovih smeša u temperaturnom opsegu od T=(288.15-333.15) K i na atmosferskom pritisku. Eksperimentalno su merene gustine, indeksi refrakcije i viskoznosti ekoloških rastvarača u smeši sa industrijskim zagađivačima. Iz eksperimentalnih podataka izračunate su dopunske molarne zapremine E V , promena viskoznosti Δη, promena indeksa refrakcije nD kao i dopunske termodinamičke veličine: E G dopunska Gibsova energija aktivacije viskoznog toka, E S dopunska enrtopija i E H dopunska entalpija, koeficijent izobarske ekspanzije α, dopunski koeficijent izobarske ekspanzije αE. Izračunate termodinamičke veličine su korišćene za analizu specifičnih molekulskih interakcija i efekata mešanja između komponenata smeša, uzimajući u obzir geometrijska pakovanja između komponenata i uticaj temperature. Ravnotežni podaci čvrsto - tečno za sva četiri binarna sistema su uspešno korelisani NRTL modelom sa dva različita temperaturno zavisna parametra, 12 g i 21 g Fourier-ova transformaciona infracrvena (FT-IR) spektroskopija binarnih smeša nikotina sa alkoholima i odgovarajućih čistih komponenata izvedena je na 298.15 K. u cilju pojašnjenja molekulske strukture, intra - i inter - molekulskih interakcija u rastvorima. Modelovanje viskoziteta rađeno je sa dva modela: modelima doprinosa grupa UNIFAC-VISCO i ASOG-VISCO modelima, i korelativnim McAllister dvoparametarski three-body i troparametarski four-body modelima...In this doctoral dissertation, binary and pesudobinary mixtures were experimentally determined. Those were thermodynamic equilibrium liquid - liquid and solid - liquid, as well as the influence of adding different co - solvents on the phase balance displacement at atmospheric pressure and in the temperature range from 288.15 K to 371.15 K. All obtained results are presented graphically by forming phase diagrams of temperature - content. Measurements of equilibrium, volumetric and transport properties of multicomponent ecological solvent systems were performed: ionic liquids, polymers and alcohols with organic solvents. The thermodynamic properties of pure components and their mixtures in the temperature range from T = (288.15-333.15) K and at atmospheric pressure were determined experimentally. Density, refractive indices and viscosity of organic solvents in mixtures with industrial pollutants were experimentally measured. Complementary molar volumes E V , change in viscosity Δη, change in refractive index nD , as well as additional thermodynamic sizes were computed from the experimental data: E G additional Gibbs viscosity current activation energy, E S supplemental entropy and E H supplemental enthalpy, coefficient of isobar expansion α, supplementary iso-expansion expansion ekspanzije αE. The calculated thermodynamic quantities were used to analyze specific molecular interactions and mixing effects between the components of the mixture, taking into account the geometric packings between the components and the effect of the temperature. The equilibrium data firmly-fluently for all four binary systems were successfully correlated with the NRTL model with two different temperature-dependent parameters 12 g and 21 g Fourier's transformation infrared (FT-IR) spectroscopy of binary mixtures of nicotine with alcohols and corresponding pure components was performed at 298.15 K in order to clarify molecular structure and intra - and intermolecular interactions in solutions..

Antagonism between cadmium and magnesium: a possible role of magnesium in therapy of cadmium intoxication

One of the important mechanisms of cadmium (Cd) toxicity is its interactions with bioelements, including magnesium (Mg). Exposure to Cd leads to disturbances in Mg metabolism in the organism, while Mg supplementation has an adverse effect on Cd absorption, accumulation and toxicity. According to the available results, which indicate a protective role of Mg against Cd toxicity, it remains to be seen whether magnesium may influence the important unsolved problem of Cd intoxication therapy. In this review, the interactions between the toxic metal Cd and the bioelement Mg are discussed on the basis of the available literature and our own results. We discuss these interactions mainly based on experimental data because data from human studies are scarce

Thermodynamic and spectroscopic interpretation of molecular interactions of nicotine plus alcohol binary mixtures

Density rho, viscosity eta and refractive index n(D) have been experimentally measured for four binary mixtures nicotine + 1-butanol, nicotine + 2-butanol, nicotine + 1,2-propanediol and nicotine + 1,3-propanediol over the temperature range T = (293.15-323.15) K with temperature step 5 K and at atmospheric pressure. Excess molar volumes V-E, viscosity deviations Delta eta, deviations in refractive index Delta n(D), excess Gibbs free energy of activation of viscous flow Delta G*(E), thermal expansion coefficients a, excess thermal expansion coefficients alpha(E), partial molar volumes (V) over bar (i), excess partial molar volumes (V) over bar (E)(i) and it's values at infinite dilutions (V) over bar (E,infinity)(i) were calculated from experimental data and used to analyze non-ideal behavior of mixtures. Fourier-transform infrared analysis of binary mixtures and corresponding pure components was performed at 298.15 K in order to gain insight into the molecular structure of mixtures and possible intermolecular interactions. Performed infra-red analysis confirms the presence of hydrogen bonding between unlike compounds, except for the system nicotine + 1-butanol. Here, the non-ideal behavior of mixtures is contributed to strong intermolecular interaction or in the case of nicotine + 1-butanol due to geometrical packing or dispersion forces of different species

Zinc, copper or magnesium supplementation against cadmium toxicity: An experimental study

Cadmium (Cd) is currently one of the most important toxic metals in occupational and environmental toxicology. It causes adverse effects on kidneys, liver, lungs, bones, testes, etc, and is classified in group 1 of human carcinogens. However, the mechanisms of Cd toxicity, particularly the role in disturbances of bioelements, are still not clear. Furthermore, there is at present no clinically useful chelating agent for the treatment of cadmium poisoning. According to the available results on antagonism between Cd and certain bioelements it remains to be answered whether zinc (Zn), copper (Cu) or magnesium (Mg) supplementation could have a protective effect against cadmium toxicity. This chapter displays present knowledge on interactions between toxic metal cadmium and essential metals Zn, Cu and Mg accompanied by our own investigations on this topic. In this work the influence of supplemental Zn, Cu or Mg on Cd content in blood, urine, brain, liver, heart, kidneys, lungs, pancreas, spleen, muscles and bones in rabbits exposed to cadmium has been investigated. The rabbits were divided into 5 groups: control group; Cd group-animals treated per os for 28 days with 10 mg Cd/kg b.w./day. The other four groups received daily 10 mg Cd/kg b.m. and bioelements: Cd+Mg group - 40 Mg/kg b.w.; Cd+Zn group - 20 mg Zn/kg b.w.; Cd+Cu group - 10 mg Cu/kg b.w. The cadmium concentration was determined by atomic absorption spectrophotometry. Zn and Mg supplementation decreased blood Cd although no significant changes of cadmium level were observed in urine. Both bioelements caused significant decrease of cadmium content in kidneys, spleen and bones, while Zn treatment additionally reduced cadmium content in brain. On the contrary, copper even increased Cd level in blood, liver and heart. The obtained results indicate antagonism between Zn and Cd, as well as Mg and Cd. These findings confirm the beneficial effect of Zn and Mg on Cd content and thus open the possibility of a new approach to the therapy and prophylaxis of Cd intoxication. Anyhow, Mg supplementation has advantage over Zn as it has positive effect on Cd level in the organism, but contrary to Zn, induces no marked disturbances of investigated bioelements

Effects of solid poly (ethylene glycols) addition to the solutions of aniline or N,N-dimethylaniline with water: Experimental measurements and modelling

In this work, the liquid-liquid and solid-liquid phase behaviour of ten aqueous pseudo-binary and three binary systems containing polyethylene glycol (PEG) 2050, polyethylene glycol 35000, aniline, N,N-dimethylaniline and water, in the temperature range 298.15-350.15 K and at ambient pressure of 0.1 MPa, was studied. The obtained temperature-composition phase diagrams showed that the only functional co-solvent was PEG2050 for aniline in water, while PEG35000 even showed a clear anti-solvent effect in the N,N-dimethylaniline aqueous system. The experimental solid-liquid equilibria (SLE) data have been correlated by the non-random two-liquid (NRTL) model, and the correlation results are in accordance with the experimental results

Effect of magnesium pretreatment on reduced glutathione levels in tissues of mice exposed to acute and subacute cadmium intoxication: a time course study

The study was designed to investigate the role of magnesium (Mg) pretreatment on reduced glutathione (GSH) levels in kidney, liver and testis of mice intoxicated with cadmium (Cd). Animals were divided into four groups: I - controls, 11 - Cd group: mice intoxicated with Cd, III - Mg+Cd group: mice given Mg 1 h before Cd, and IV - Mg group: mice given only Mg. In acute time - response studies, the single oral dose of Cd was 20 mg Cd/kg b.w. and 40 mg Mg/kg b.w. GSH levels were determined after 4, 6, 12, 24, and 48 h. In subacute experiments, mice were given 10 mg Cd/kg b.w. orally every day and 20 mg Mg/kg b.w., and GSH content was determined in investigated organs after 1 and 2 weeks. Acute cadmium intoxication significantly decreased the GSH content in liver 4, 6 and 12 h after Cd administration and increased GSH in kidney after 12, 24 and 48 h, but did not cause significant GSH alterations in testis. Mg pretreatment reduced the observed changes of GSH content in kidney and liver. Subacute Cd intoxication induced diminished renal GSH levels compared with the controls while the increased GSH levels were observed in liver and testes after 2 weeks Cd treatment. Mg pretreatment was efficient in restoring renal and testis GSH levels towards the control group, but had no effect on hepatic GSH