Nicotine aqueous solutions: pH-measurements and salting-out effects - analysis of the effective Gibbs energies of hydration and ionic strengths of the solutions

This work is a continuation of our previous studies on the phase demixing - salting-out effects - in aqueous nicotine solutions. Thus, pH measurements were carried out allowing a brief analysis of the existing hydrogen bond interactions. Salting-out effects - the related experimental cloud point shifts - provoked by the addition of two inorganic salts, potassium nitrate and sodium sulfate, which were not studied so far, were determined. Analysis of the current and our previously reported salting-out/or salting-in phenomena in nicotine aqueous solutions was performed. In this respect, five studied salts were included: four inorganic salts (sodium chloride, potassium nitrate, sodium sulfate and sodium phosphate (Na3PO4)) and ionic liquid 1-ethyl-3-methylimidazolium ethyl sulfate ([C2mim][EtSO4] or ECOENG212?). Based on the pH measurements the effective Gibbs energies of hydration and ionic strengths of the respective ternary solutions were calculated and plotted against the related cloud-point shifts caused by the addition of the salts. For the studied salts, the results and diagram obtained within this work may be used to predict the cloud-points shifts, based on the related quantities of the salts added and/or the molar Gibbs energies of hydration and/or ionic strengths requested in each case.

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Synthesis of Thermo-Responsive Fluorinated Star-Shaped Polymers by Living Cationic Polymerization

MRS Proceedings ◽

10.1557/opl.2011.130 ◽

2011 ◽

Vol 1312 ◽

Cited By ~ 1

Author(s):

Tomomi Irita ◽

Katsuhiko Imoto ◽

Takabumi Nagai ◽

Sadahito Aoshima

Keyword(s):

Aqueous Solutions ◽

Cloud Point ◽

Cationic Polymerization ◽

Solution Temperature ◽

Responsive Polymers ◽

Molecular Weight Distributions ◽

Living Cationic Polymerization ◽

Bifunctional Initiators ◽

Cloud Points ◽

End Group

ABSTRACTWell-controlled fluorinated star-shaped polymers with oxyethylene units were designed and synthesized by living cationic polymerization. These fluorinated star-shaped polymers were prepared using successive fluorinated initiators to generate fluorinated, end-functionalized and hydrophilic segments with oxyethylene. Poly(vinyl ether)s with oxyethylene units are known to be thermo-responsive polymers that exhibit a lower critical solution temperature (LCST) in aqueous solutions. These novel fluorine-containing star-shaped polymers with oxyethylene were also thermo-responsive, as expected. In addition, the hetero-fluorinated star-shaped polymers with oxyethylene segments and different fluorine compositions were synthesized with various bifunctional initiators by living cationic polymerization having narrow molecular weight distributions (Mw/Mn=1.23−1.29) and contained very little, if any, presence of the linear homopolymer precursor, as evidenced by GPC. The LCST of this polymer depended on the end group fluorine composition and significant changes in cloud points were observed in water, as confirmed by static light scattering (SLS) measurements. As an example, aqueous solutions the star-shaped polymers without fluorine terminal groups showed no cloud point below up to 60 ºC in aqueous solution. After the fluoro-functionality was incorporated into the terminal groups, the cloud point of the aqueous solutions decreased to almost 20 ºC.

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Salting-Out of n-Propyl Alcohol with Potassium Nitrate from Aqueous Solutions

Russian Journal of Applied Chemistry ◽

10.1007/s11167-005-0303-2 ◽

2005 ◽

Vol 78 (3) ◽

pp. 394-398

Author(s):

S. I. Sinegubova ◽

D. G. Cherkasov ◽

K. K. Il’in

Keyword(s):

Aqueous Solutions ◽

Potassium Nitrate ◽

Salting Out ◽

Propyl Alcohol

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Salting-out of isopropyl alcohol from aqueous solutions with potassium nitrate

Russian Journal of Applied Chemistry ◽

10.1007/s11167-005-0194-2 ◽

2004 ◽

Vol 77 (12) ◽

pp. 1924-1928 ◽

Cited By ~ 2

Author(s):

S. I. Sinegubova ◽

K. K. Il?in ◽

D. G. Cherkasov ◽

V. F. Kurskii ◽

N. V. Tkachenko

Keyword(s):

Aqueous Solutions ◽

Isopropyl Alcohol ◽

Potassium Nitrate ◽

Salting Out

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Salting out of triethylamine from aqueous solutions by potassium nitrate

Russian Journal of Applied Chemistry ◽

10.1134/s1070427211050107 ◽

2011 ◽

Vol 84 (5) ◽

pp. 798-802 ◽

Cited By ~ 1

Author(s):

D. G. Cherkasov ◽

K. K. Il’in

Keyword(s):

Aqueous Solutions ◽

Potassium Nitrate ◽

Salting Out

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Enhanced Adsorption of Bisphenol A from Aqueous Solution with 2-Vinylpyridine Functionalized Magnetic Nanoparticles

Polymers ◽

10.3390/polym10101136 ◽

2018 ◽

Vol 10 (10) ◽

pp. 1136 ◽

Cited By ~ 10

Author(s):

Qiang Li ◽

Fei Pan ◽

Wentao Li ◽

Dongya Li ◽

Haiming Xu ◽

...

Keyword(s):

Bisphenol A ◽

Aqueous Solutions ◽

Adsorption Capacity ◽

Magnetic Nanoparticle ◽

Maximum Adsorption Capacity ◽

Salting Out ◽

Functionalized Magnetic Nanoparticles ◽

Ft Ir ◽

Fe3o4 Nanospheres ◽

Enhanced Adsorption

In this study, a novel 2-vinylpyridine functionalized magnetic nanoparticle (Mag-PVP) was successfully prepared. The prepared Mag-PVP was characterized by transmission electronic microscopy (TEM), Fourier transform infrared spectrophotometry (FT-IR), vibrating sample magnetometry (VSM) and thermogravimetric analysis (TGA), and was used for the adsorption of bisphenol A (BPA) from aqueous solutions. Mag-PVP, which is composed of Fe3O4 nanoparticles and poly divinylbenzene-2-vinylpyridine (with a thickness of 10 nm), exhibited magnetic properties (Ms = 44.6 emu/g) and thermal stability. The maximum adsorption capacity (Qm) of Mag-PVP for BPA obtained from the Langmuir isotherm was 115.87 mg/g at 20 °C, which was more than that of Fe3O4 nanospheres. In the presence of NaCl, the improved adsorption capacity of Mag-PVP was probably attributed to the screening effect of Mag-PVP surface charge and salting-out effect. In the presence of CaCl2 and humic acid (HA), the adsorption capacity of BPA decreased due to competitive adsorption. The adsorption of BPA by Mag-PVP increased slightly with the increase in pH from 3.0 to 5.0 and obtained the largest adsorption amount at pH 5.0, which was probably attributed to hydrogen bonding interactions. Moreover, in actual water, Mag-PVP still showed excellent adsorption performance in removing BPA. The high adsorption capacity and excellent reusability performance in this work indicated that Mag-PVP was an effective adsorbent for removing BPA from aqueous solutions.

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