Viscosity of sodium carboxymethylcellulose in ethylene glycol-water mixed solvent media: Separation of the influences of polyion conformation and electrostatic interactions on the reduced viscosity

2010 ◽  
Vol 48 (11) ◽  
pp. 1196-1202 ◽  
Author(s):  
Ramesh Sharma ◽  
Bijan Das ◽  
Prabir Nandi ◽  
Chanchal Das
Soft Matter ◽  
2019 ◽  
Vol 15 (12) ◽  
pp. 2511-2516 ◽  
Author(s):  
Hongyao Yin ◽  
Yujun Feng ◽  
Peixun Li ◽  
James Doutch ◽  
Yixiu Han ◽  
...  

Cryogenic wormlike micellar solutions with a freezing point far below 0 °C and unique rheological behavior are fabricated from the self-assembly of a C22-tailed zwitterionic surfactant in a mixed solvent of ethylene glycol and water. Such fluids could find applications in areas where viscoelasticity is highly desired at subfreezing temperatures.


Energies ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 124
Author(s):  
Yang Han ◽  
Kent Hoekman ◽  
Umakanta Jena ◽  
Probir Das

This study reviewed and summarized the literature regarding the use of alcohols during hydrothermal liquefaction (HTL) of algal biomass feedstocks. The use of both pure alcohols and alcohol-water co-solvents were considered. Based upon this review, laboratory experiments were conducted to investigate the impacts of different alcohol co-solvents (ethanol, isopropanol, ethylene glycol, and glycerol) on the HTL treatment of a specific saltwater microalga (Tetraselmis sp.) at two temperatures: 300 °C and 350 °C. Based on their performance, two co-solvents, isopropanol and ethylene glycol, were selected to explore the effects of varying solvent concentrations and reaction temperatures on product yields and biocrude properties. The type and amount of added alcohol did not significantly affect the biocrude yield or composition. Biocrude yields were in the range of 30–35%, while a nearly constant yield of 21% insoluble products was observed, largely resulting from ash constituents within the algal feedstock. The benefits of using alcohol co-solvents (especially isopropanol) were the reduced viscosity of the biocrude products and reduced rates of viscosity increase with biocrude aging. These effects were attributed mainly to the physical properties of the co-solvent mixtures (solubility, polarity, density, etc.) rather than chemical processes. Under the reaction conditions used, there was no evidence that the co-solvents participated in biocrude production by means of hydrogen donation or other chemical processes. Recovery and recycling of the co-solvent present various challenges, depending upon the type and amount of the co-solvent that is used. For example, glycol solvents are recovered nearly completely within the aqueous product stream, whereas simple alcohols are partitioned between the biocrude and aqueous product streams. In commercial applications, the slight benefits provided by the use of co-solvents must be balanced by the challenges of co-solvent recovery and recycling.


2018 ◽  
Vol 7 (3.3) ◽  
pp. 143
Author(s):  
Veerati Radhika ◽  
. .

Nucleophilic substitution reaction of benzyl bromide and cyclicamines in ethanol aqueous intermediate reactivity can suggest that the nucleophile increases through their pKa values. A linear correlation exists between computed values of the dipole moment, rate and electronegativity of the nucelophiles. The two reactants suggest that frontier molecular orbital interactions ion-solvation and correlation of time with the HOMO-LUMO breach of that the reaction.  But it is not orbital controlled as well as forbidden by the electrostatic interactions along with mixed solvent composition between the reactants. The influence on the solvation of ions before reaction has been discuss with facilitate by R-factor. Thermodynamic properties are evaluate and report. The consequences of the learning to be interpreted in terms of ion-solvent exchanges and solvent properties comparing with electrostatic interaction between the reactants.   


2021 ◽  
Author(s):  
Liang Huang ◽  
Xianghui Jin ◽  
xumei Tao ◽  
Chen Yang ◽  
Yuanyuan Han

Abstract In this paper, NiAlCe hydrotalcite was prepared by co-precipitation method and hydrothermal method in different volume fractions of ethylene glycol-water mixed solvent and polyethylene glycol-water mixed solvent, and the effect of photocatalytic degradation of methyl orange under ultraviolet light was studied. Samples were characterized by XRD, XPS, UV-Vis and FT-IR in order to find the reasons for the improvement of photocatalytic performance under co-solvent system. NiAlCe-10%EG(h) and NiAlCe-15%PEG(h) had smaller particle size, which was beneficial to photocatalytic performance. The degradation rate of methyl orange could reach up to 100% in 42 min using NiAlCe hydrotalcite with 10% volume fraction of EG and in 48 min using NiAlCe hydrotalcite with 15% volume fraction of PEG. The photocatalytic effect of NiAlCe hydrotalcite samples prepared by hydrothermal method were better than that prepared by co-precipitation method. This provided a new type of catalyst for the degradation of dyes: preparing with ethylene glycol-water mixed solvent.


2018 ◽  
Vol 876 ◽  
pp. 52-56 ◽  
Author(s):  
Huu Vinh Nguyen ◽  
Tran Van Thuan ◽  
Sy Trung Do ◽  
Duy Trinh Nguyen ◽  
Dai Viet Nguyen Vo ◽  
...  

We report the facial synthesis of BiVO4crystals with different morphologies by the solvothermal and hydrothermal process. The phase structure and morphology as-synthesized samples were characterized by XRD, FE-SEM, and UV-vis DRS spectroscopy. We also investigated the photocatalytic activity of BiVO4for the decomposition of rhodamine B (RhB) under visible light irradiation. The results showed that oliver-like BiVO4was obtained when using the mixed solvent of ethylene glycol and water while starflower-like BiVO4was obtained using the mixed solvent of ethylene glycol monomethyl ether and water. The hydrothermal evolution process the BiVO4product with a rod-like morphology. Oliver-like BiVO4with pure monoclinic scheelite phase and high specific surface area exhibits efficient photodegradation of RhB (k = 7.82x10-3min-1).


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