Vitrification Assessment: Thermal Analysis of Cryoprotective Aqueous Solutions 1,2 Propanediol and Ethylene Glycol

2018 ◽  
Vol 16 (3) ◽  
pp. 207-216
Author(s):  
Muhamad Abidalla ◽  
Pio F. Roversi
Keyword(s):  
Thermal Analysis ◽  
Ethylene Glycol ◽  
Aqueous Solutions

scholarly journals Synthesis of Mn(II)-containing paratungstate B from aqueous solutions acidified by acetic acid

2021 ◽  
pp. 39-48
Keyword(s):  
Thermal Analysis ◽  
Acetic Acid ◽  
Aqueous Solutions ◽  
Equilibrium Constants ◽  
Background Electrolyte ◽  
Equilibrium Processes ◽  
Transformation Processes ◽  
Paratungstate B ◽  
Solution Acidity ◽  
Tungstate Anion

The method of pH-potentiometric titration and mathematical simulation were used to study the equilibrium processes in aqueous solutions of the WO42––CH3COOH–H2O system in the acidity range Z=(CH3COOH)/(Na2WO4)=0.8–1.7 at СW=0.01 mol L–1 and T=2980.1 K, a constant ionic strength being maintained by sodium nitrate as a background electrolyte ((NaNO3)=0.10 mol L–1). We developed the models of polyoxotungstate anions formation and the equilibrium transformation processes, which adequately describe experimental pH vs. Z dependences. It was found that acetic acid using to create the solution acidity that is necessary for the formation of isopoly tungstate anion contributes only to the formation of protonated paratungstate B anions Нх[W12O40(ОН)2](10–х)– (where x=0–4). We calculated the logarithms of the concentration equilibrium constants of the polyanion formation and plotted the distribution diagrams. Double sodium-manganese(II) paratungstate B Na8(H2O)28Mn(H2O)2[H2W12O42]4H2O was synthesized at Z=1.00 to confirm the results of the mathematical modeling. The chemical composition of the prepared salt was established by chemical elemental analysis, thermal analysis, FTIR spectroscopy, and single crystal X-ray analysis. The stepwise process of salt dehydration was studied by means of differential thermal analysis.

A2BA2Block Copolymers of Poly(N-isopropylacrylamide) (A) and Poly(ethylene glycol) (B): Synthesis and Thermal Gelation Properties of Aqueous Solutions

2010 ◽  
Vol 48 (2) ◽  
pp. 177-185 ◽  
Author(s):  
Mircea Teodorescu ◽  
Ioana Negru ◽  
Paul O. Stanescu ◽  
Constantin Drăghici ◽  
Anamaria Lungu ◽  
...  
Keyword(s):  
Ethylene Glycol ◽  
Aqueous Solutions ◽  
Poly Ethylene Glycol ◽  
Thermal Gelation ◽  
Poly Ethylene
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