Studies of proton-transfer equilibria of different charge type acids in the glycerol-water solvent system at 25.degree.C

1987 ◽  
Vol 32 (1) ◽  
pp. 117-121 ◽  
Author(s):  
Amrita Lal De ◽  
Arup Kumar Atta
2012 ◽  
Vol 116 ◽  
pp. 190-194 ◽  
Author(s):  
Yu Yang ◽  
Changwei Hu ◽  
Mahdi M. Abu-Omar
Keyword(s):  

2016 ◽  
Vol 860 ◽  
pp. 81-84
Author(s):  
Bandu Madhukar Kale ◽  
Jakub Wiener ◽  
Jiri Militky ◽  
Hafiz Shahzad Maqsood

Cellulose solution was used for coating and it was prepared by dissolving pulp cellulose in Urea-Thiourea-NaOH-Water solvent system. Reactive Red 240 dye was used for dyeing the coated as well as control cotton fabric. The effect of cellulose coating on the dyeing properties of cotton fabric was studied by measuring K/S values of the coated substrate at various concentrations of cellulose and dye. K/S value decreased after coating cellulose on the surface of cotton fabric. The lightness of cotton fabric increased after cellulose coating. SEM micrographs revealed that coated cellulose was attached to cotton fibers. Tensile strength increased after cellulose coating.


Catalysts ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 517 ◽  
Author(s):  
Huiping Ji ◽  
Jie Fu ◽  
Tianfu Wang

Conversion of biorenewable feedstocks into transportation fuels or chemicals likely necessitates the development of novel heterogeneous catalysts with good hydrothermal stability, due to the nature of highly oxygenated biomass compounds and the prevalence of water as a processing solvent. The use of carbon-based materials, derived from sugars as catalyst precursors, can achieve hydrothermal stability while simultaneously realizing the goal of sustainability. In this work, the simultaneous pyrolysis of glucose and taurine in the presence of multi-walled carbon nanotubes (MWCNTs), to obtain versatile solid acids, has been demonstrated. Structural and textural properties of the catalysts have been characterized by TEM, TGA, and XPS. Additionally, solid state nuclear magnetic resonance (ssNMR) spectroscopy has been exploited to elucidate the chemical nature of carbon species deposited on the surface of MWCNTs. Al(OTf)3, a model Lewis acidic metal salt, has been successfully supported on sulfonic groups tethered to MWCNTs. This catalyst has been tested for C6 sugar dehydration for the production of HMF in a tetrahydrofuran (THF)/water solvent system with good recyclability.


2010 ◽  
Vol 2010 ◽  
pp. 1-8 ◽  
Author(s):  
Bachar Zebib ◽  
Zéphirin Mouloungui ◽  
Virginie Noirot

The purpose of present study was to stabilize curcumin food pigment by its complexation with divalent ions like , in “green media” and evaluate its stability in vitro compared to curcumin alone. The curcumin complexes were prepared by mechanical mixture of curcumin and sulfate salts of each metal (metal : curcumin 1/1mol) into unconventional and nontoxic glycerol/water solvent. Two stoichiometry of complex were obtained, 1 : 1 and 1 : 2 (metal/curcumin), respectively. On evaluation of in vitro stability, all complexes were found to provide a higher stability from curcumin alone.


1988 ◽  
Vol 14 (4) ◽  
pp. 531-535 ◽  
Author(s):  
Syogo Takahashi ◽  
Kazutoshi Otake ◽  
Tolu Takahashi ◽  
Akihiro Iguchi

1972 ◽  
Vol 50 (11) ◽  
pp. 1729-1733 ◽  
Author(s):  
E. A. Symons ◽  
E. Buncel

Sigma-complex formation between 1,3,5-trinitrobenzene (TNB) and hydroxide ion has been studied quantitatively as a function of medium composition for part of the dimethylformamide (DMF)–water solvent system by spectrophotometric methods. Only a 1:1 complex is detected under the conditions of measurement, with [TNB] ≥ [OH−]. The equilibrium constant (Keq) for complex formation in 22 mol % DMF has the value 3 × 10−3 l mol−1, compared with 3 l mol−1 in purely aqueous medium. Further increases in Kcq occur as the DMF content of the medium is raised; in 50 mol % DMF Keq ≈ 105, but reliable Keq values could not be obtained in this region of medium composition. The increase in Keq with increasing DMF content is interpreted largely on the basis of hydroxide ion desolvation.


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