Effect of water concentration on photoreduction of anthraquinone-2-sulfonate by 2-propanol in aqueous acetonitrile solution

1987 ◽  
Vol 91 (26) ◽  
pp. 6547-6551 ◽  
Author(s):  
Akihiro. Wakisaka ◽  
Thomas W. Ebbesen ◽  
Hirochika. Sakuragi ◽  
Katsumi. Tokumaru
Keyword(s):  
Water Concentration ◽  
Acetonitrile Solution ◽  
Aqueous Acetonitrile ◽  
Effect Of Water

scholarly journals Fast anisotropic Mg and H diffusion in wet forsterite

2021 ◽  
Author(s):  
Joshua Muir ◽  
Feiwu Zhang ◽  
Andrew Walker
Keyword(s):  
Density Functional ◽  
Diffusion Rate ◽  
Water Concentration ◽  
Experimental Conditions ◽  
Functional Theory ◽  
Strong Function ◽  
Effect Of Water ◽  
Large Numbers ◽  
Relationship Of ◽  
The Relationship

Mg diffusion, which is important for properties of forsterite such as conductivity and deformation, is a strong function of water content. The mechanism behind this effect, however, has not been fully elucidated. In this study we use Density Functional Theory to predict the diffusivity of 〖(2H)〗_Mg^X and we find that they are around 1000 times slower than H-free Mg vacancies V_Mg^''. In most wet conditions the concentration of 〖(2H)〗_Mg^X is much higher than that of V_Mg^'' and thus the primary effect of water on increasing the Mg-diffusion rate in forsterite is by producing large numbers of H-bearing Mg vacancies. A water induced increase in diffusion rate is predicted to be accompanied by a large increase in diffusional anisotropy primarily in the [001] direction. Using a previously developed model of H distribution in forsterite we predict that the effect of water on Mg diffusion is strongly dependent upon environmental conditions such as pressure or temperature. An exponent (r) describing the relationship of water concentration to Mg diffusion is found to vary between 0.5-1.6 across common experimental conditions with pressure decreasing this exponent and temperature increasing it. With 100 wt. ppm water Mg diffusion rates are predicted to increase by over 2 orders of magnitude at high temperature and low pressure (2000 K, 0 GPa) and by over 3.5 orders of magnitude at low temperature and high pressure (1000 K, 10 GPa) while the anisotropy of diffusion is predicted to increase by ~2/over 5.5 orders of magnitude respectively. A conversion from “dry” to “wet” rheological laws is predicted to occur at <~1 ppm. These results suggest that Mg diffusion in wet forsterite could vary considerably throughout mantle conditions in ways that cannot be captured with a simple one component equation. Finally we considered the effects of the diffusion of H-bearing Mg vacancies on conductivity in forsterite and olivine. We combined our diffusivity results with experimentally determined results for phonon conductivity but this predicted significaly lower conductivities than have been observed experimentally in olivine, particularly at low temperatures (~1000 K). This suggests that the effect of water on olivine conductivity is not primarily due to bulk 〖(2H)〗_Mg^X diffusion and operates via a different unknown mechanism.

scholarly journals Process Simulation of the Separation of Aqueous Acetonitrile Solution by Pressure Swing Distillation

Processes ◽  
2019 ◽  
Vol 7 (7) ◽  
pp. 409 ◽  
Author(s):  
Jing Li ◽  
Keliang Wang ◽  
Minglei Lian ◽  
Zhi Li ◽  
Tingzhao Du
Keyword(s):  
Acetonitrile Solution ◽  
Optimum Process ◽  
Total Annual Cost ◽  
Heat Integration ◽  
Reflux Ratio ◽  
Water Mixture ◽  
Aqueous Acetonitrile ◽  
Design Variables ◽  
Pressure Swing ◽  
Pressure Swing Distillation

The separation of aqueous acetonitrile solution by pressure swing distillation (PSD) was simulated and optimized through Aspen Plus software. The distillation sequence of the low pressure column (LPC) and high pressure column (HPC) was determined with a phase diagram. The pressures of the two columns were set to 1 and 4 atm, respectively. Total annual cost (TAC) was considered as the objective function, and design variables, such as the tray number, the reflux ratio, and the feeding position, were optimized. The optimum process parameters were obtained. For the reduction of energy consumption, the PSD with full-heat integration was designed. The TAC of this method is lower by 32.39% of that of the PSD without heat integration. Therefore, it is more economical to separate acetonitrile and water mixture by PSD with full-heat integration, which provides technical support for the separation design of such azeotropes.

Poly (SNS) Quantitative Electrosynthesis and Electrodissolution

1993 ◽  
Vol 328 ◽  
Author(s):  
T. F. Otero ◽  
E. Brillas ◽  
J. Carrasco ◽  
A. Figueras
Keyword(s):  
Conducting Polymers ◽  
Thick Films ◽  
Industrial Applications ◽  
Cathodic Reduction ◽  
Acetonitrile Solution ◽  
Aqueous Acetonitrile ◽  
Acetonitrile Solutions

ABSTRACTThe electrogeneration and electrodissolution of poly (SNS) have been improved by using aqueous acetonitrile solutions having a 1% (ν/ν) of water constant. Compact, adherent and thick films (until 0.4 Mg cm-2) were galvanostatically electrogenerated. The electrodeposited (oxidized) polymer is insoluble in 0.1 M L?CIO4 aqueous acetonitrile solution and solubilizes by cathodic reduction. Both, electrogeneration and electrodissolution, are faradaic processes. Those facts mimic electrodeposition and electroerosion of metals and their concomitant industrial applications. New technological possibilities using polymers in electrophotography, electroreprography, electropolishing, electro-erosion and electromachining are open through polymeric electrodissolution altogether to a new processible way, through the obtained solution, for the conducting polymers.

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