scholarly journals Carbon Monoliths with Hierarchical Porous Structure for All-Vanadium Redox Flow Batteries

Batteries ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 55
Author(s):  
Jose Francisco Vivo-Vilches ◽  
Blagoj Karakashov ◽  
Alain Celzard ◽  
Vanessa Fierro ◽  
Ranine El Hage ◽  
...  
Keyword(s):  
Sodium Chloride ◽  
Textural Properties ◽  
Initial Mixture ◽  
Carbon Surface ◽  
Electrochemical Performances ◽  
Oxidation Potentials ◽  
Hierarchical Porous ◽  
The Difference ◽  
Vanadium Redox ◽  
Composition Changes

Carbon monoliths were tested as electrodes for vanadium redox batteries. The materials were synthesised by a hard-templating route, employing sucrose as carbon precursor and sodium chloride crystals as the hard template. For the preparation process, both sucrose and sodium chloride were ball-milled together and molten into a paste which was hot-pressed to achieve polycondensation of sucrose into a hard monolith. The resultant material was pyrolysed in nitrogen at 750 °C, and then washed to remove the salt by dissolving it in water. Once the porosity was opened, a second pyrolysis step at 900 °C was performed for the complete conversion of the materials into carbon. The products were next characterised in terms of textural properties and composition. Changes in porosity, obtained by varying the proportions of sucrose to sodium chloride in the initial mixture, were correlated with the electrochemical performances of the samples, and a good agreement between capacitive response and microporosity was indeed observed highlighted by an increase in the cyclic voltammetry curve area when the SBET increased. In contrast, the reversibility of vanadium redox reactions measured as a function of the difference between reduction and oxidation potentials was correlated with the accessibility of the active vanadium species to the carbon surface, i.e., was correlated with the macroporosity. The latter was a critical parameter for understanding the differences of energy and voltage efficiencies among the materials, those with larger macropore volumes having the higher efficiencies.

scholarly journals Effect of Air Oxidation on Texture, Surface Properties and Dye Adsorption of Wood-Derived Porous Carbon Materials

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1675 ◽  
Author(s):  
Suhong Ren ◽  
Liping Deng ◽  
Bo Zhang ◽  
Yafang Lei ◽  
Haiqing Ren ◽  
...  
Keyword(s):  
Surface Area ◽  
Functional Groups ◽  
Porous Carbon ◽  
Carbon Materials ◽  
Dye Adsorption ◽  
Carbon Surface ◽  
Air Oxidation ◽  
Activation Temperature ◽  
Porous Carbon Materials ◽  
Hierarchical Porous

Hierarchical porous carbon materials made from cork were fabricated using a facile and green method combined with air activation, without any templates and chemical agents. The influence of air activation on the texture and other surface characteristics of the carbon materials were evaluated by various characterization techniques. Results indicate that air oxidation can effectively improve the surface area and the hierarchical porous structure of carbon materials, as well as increase the number of oxygen-containing functional groups on the carbon surface. The specific surface area and the pore volume of the carbon material activated by air at 450 °C (C800-M450) can reach 580 m2/g and 0.379 cm3/g, respectively. These values are considerably higher than those for the non-activated material (C800, 376 m2/g, 0.201 cm3/g). The contents of the functional groups (C–O, C=O and O–H) increased with rising activation temperature. After air activation, the adsorption capacity of the carbon materials for methylene blue (MB) and methyl orange (MO) was increased from 7.7 and 6.4 mg/g for C800 to 312.5 and 97.1 mg/g for C800-M450, respectively. The excellent dye removal of the materials suggests that the porous carbon obtained from biomass can be potentially used for wastewater treatment.

scholarly journals ACRYLAMIDE (CO)POLYMERS DISSOLUTION IN WATER-SALINE SOLUTIONS

2018 ◽  
Vol 54 (3) ◽  
pp. 329-337 ◽  
Author(s):  
D. N. Davlyud ◽  
P. D. Vorobiev ◽  
Yu. V. Matrunchik ◽  
E. V. Vorobieva ◽  
N. P. Krutko
Keyword(s):  
Sodium Chloride ◽  
Potassium Chloride ◽  
Solvent System ◽  
Ionogenic Group ◽  
Dissolution Time ◽  
Chloride Solutions ◽  
Sodium Chloride Solutions ◽  
The Difference ◽  
Capillary Viscosimetry ◽  
Saline Solutions

Dissolution of acrylamide anionic (co)polymers in saline solutions (potassium and sodium chlorides) with concentration of 3.4 mol/l was studied by atomic absorption spectroscopy, optical microscopy, gel-test and capillary viscosimetry. It has been established that with increasing in the content of ionogenic groups and the transition from sodium chloride to potassium chloride solutions the dissolution rate of (co)polymer increases. The concentration of cations of low molecular weight electrolytes is higher in the swollen polymer phase than in the solution in the swelling stage of polymers, the difference in the counter ion content decreases with increasing dissolution time. Comparative analysis of the Huggins constant and the hydrodynamic radii of acrylamide (co)polymers has showed that increase in the interaction in polymer-solvent system is accompanied by the increase in size of macromolecular coils. The Kuhn segment of polymer macromolecules is higher in sodium chloride solutions than in potassium chloride solutions and increases with the decrease in ionogenic group content.

scholarly journals Characteristics of Activated Carbon from Oil Palm Fronds with the Addition of Sodium Carbonate (Na2CO3) and Sodium Chloride (NaCl) as an Activator

2019 ◽  
Vol 1 (1) ◽  
pp. 30-35
Author(s):  
Seri Maulina ◽  
Gewa Handika
Keyword(s):  
Activated Carbon ◽  
Sodium Chloride ◽  
Sodium Carbonate ◽  
Oil Palm ◽  
Elaeis Guineensis ◽  
Activation Temperature ◽  
Spectra Analysis ◽  
Oil Palm Fronds ◽  
The Difference ◽  
Palm Fronds

This paper aims to understand the difference in characteristics of activated carbon produced from oil palm fronds (Elaeis guineensis Jacq) through the addition of two different activators, namely sodium carbonate (Na2CO3) and sodium chloride (NaCl). To do this, activator concentration of 10 percent each with activation temperature of 600 oC were applied in the experiment. Moreover, to determine the quality of activated carbon produced, a morphological analysis of activated carbon surfaces as well as FTIR spectra analysis on activated carbon. Identification using FTIR spectrophotometer revealed that the activated carbon in this study contained functional groups of O-H, C = O, C = C, C-C, and C-H.

Tailoring the textural properties of hierarchical porous carbons for supercapacitors

2015 ◽  
Vol 159 ◽  
pp. 377-380 ◽  
Author(s):  
Yafei Zhang ◽  
Chuanxiang Zhang ◽  
Guangxu Huang ◽  
Baolin Xing ◽  
Yuling Duan
Keyword(s):  
Textural Properties ◽  
Porous Carbons ◽  
Hierarchical Porous ◽  
Hierarchical Porous Carbons

Hierarchical porous carbon microtubes derived from willow catkins for supercapacitor applications

2016 ◽  
Vol 4 (5) ◽  
pp. 1637-1646 ◽  
Author(s):  
Lijing Xie ◽  
Guohua Sun ◽  
Fangyuan Su ◽  
Xiaoqian Guo ◽  
Qingqiang Kong ◽  
...  
Keyword(s):  
Porous Carbon ◽  
Electrochemical Performances ◽  
Hierarchical Porous Carbon ◽  
Organic Electrolytes ◽  
Hierarchical Porous ◽  
Supercapacitor Applications

Hierarchical porous carbon microtubes derived from willow catkins exhibited excellent electrochemical performances in both aqueous and organic electrolytes.

The Effect of Ni Precursor Salts on Diatomite Supported Ni-Mg Catalysts in Methanation of CO2

2021 ◽  
Vol 1016 ◽  
pp. 1417-1422
Author(s):  
Chao Sun ◽  
Jugoslav Krstic ◽  
Vojkan Radonjic ◽  
Miroslav Stankovic ◽  
Patrick da Costa
Keyword(s):  
Catalytic Activity ◽  
Atmospheric Pressure ◽  
Textural Properties ◽  
Catalytic Performance ◽  
Nickel Salt ◽  
Nitrate Salt ◽  
Efficient Catalyst ◽  
Mild Conditions ◽  
The Difference ◽  
Supported Ni

This study is aimed to investigate the effect of Ni precursor salts on the properties (textural, phase-structural, reducibility, and basicity), and catalytic performance of diatomite supported Ni-Mg catalyst in methanation of CO2. The NiMg/D-X catalysts derived from various nickel salts (X = S-sulfamate, N-nitrate or A-acetate) were synthesized by the precipitation-deposition (PD) method. The catalysts were characterized by N2-physisorption, XRD, TPR-H2, and TPD-CO2 techniques. The different catalytic activity (conversion) and selectivity, observed in CO2 methanation carried out under relatively mild conditions (atmospheric pressure; temperatures: 250-450 °C) are related and explained by the difference in textural properties, metallic Ni-crystallite size, reducibility, and basicity of studied catalysts. The results showed that catalyst derived from Ni-nitrate salt (NiMg/D-N) is more suitable for the preparation of efficient catalyst for CO2 methanation than its counterparts derived from sulfamate (NiMg/D-S) or acetate (NiMg/D-A) nickel salt. The NiMg/D-N catalyst showed the highest specific surface area and total basicity, and the best catalytic performance with CO2 conversion of 63.3 % and CH4 selectivity of 80.9 % at 450 °C.

Hierarchical porous NiCo2O4/CeO2 hybrid materials for high performance supercapacitors

2018 ◽  
Vol 5 (12) ◽  
pp. 3126-3134 ◽  
Author(s):  
Chengzhen Wei ◽  
Rui Zhang ◽  
Xuan Zheng ◽  
Qinglong Ru ◽  
Qingyun Chen ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Hybrid Materials ◽  
High Performance ◽  
Solvothermal Method ◽  
Subsequent Heat Treatment ◽  
Electrochemical Performances ◽  
Hierarchical Porous

Hierarchical porous NiCo2O4/CeO2 hybrid materials are successfully synthesized via a simple solvothermal method and subsequent heat treatment and exhibit remarkable electrochemical performances in supercapacitors.

Effects of sodium chloride and betaine on hydration status of lambs at slaughter

2008 ◽  
Vol 48 (9) ◽  
pp. 1194 ◽  
Author(s):  
K. L. Pearce ◽  
D. G. Masters ◽  
R. H. Jacob ◽  
D. L. Hopkins ◽  
D. W. Pethick
Keyword(s):  
Sodium Chloride ◽  
Carcass Characteristics ◽  
Carcass Weight ◽  
Urine Specific Gravity ◽  
Hydration Status ◽  
Chloride Salt ◽  
Feeding Period ◽  
High Salt Diet ◽  
Access To Water ◽  
The Difference

Under commercial conditions in Australia, lambs are often dehydrated at slaughter despite access to water at the abattoir. Dehydration results in reduced fluid content of meat, which causes liveweight and carcass weight loss. Two experiments evaluated hydration status and carcass characteristics in lambs fed increased levels of sodium chloride (salt) and/or betaine before slaughter. Both experiments were 2 × 2 factorial designs with two levels of salt added [0 and 50 g/kg dry matter (DM)] and two levels of betaine added (0 and 6.7 g/kg DM) to the diets. The treatment diets were introduced to sheep over a 7–8-day period and then fed at 1.5 kg/day for the following 7 days. In experiment 1, 96 Poll Dorset–Merino cross wether lambs (45.9 ± 0.17 kg) were fed in individual pens and in experiment 2, 204 Merino wether lambs (43.1 ± 0.35 kg) were fed in group pens. In the first experiment, water and feed were withheld from the end of the treatment feeding period until slaughter 48 h later. In the second experiment, feed and water were withheld for the first 24 h after treatment but water was available for the next 24 h immediately before slaughter. In both experiments, consumption of the high salt diet decreased urine specific gravity and osmolarity at the end of the feeding period and after 24 h without access to water. This indicates an improved hydration status at this time. However, the difference in hydration status related to feeding salt declined during the 48-h lairage period and there were no significant differences in hot carcass weight or muscle DM among groups at slaughter. It could be concluded from this result that the addition of salt has little commercial value; however, this may not be the case. The lambs in experiment 2 did not behave according to industry expectations. They all drank water in the last 24 h in lairage and none of the groups showed severe dehydration. Further research is justified to determine if the lambs fed the diets with no added salt drunk in lairage as a learned response from the lambs fed salt and, if so, whether this can be developed into a commercial strategy. Feeding betaine did not result in any changes in hydration status or carcass characteristics.

scholarly journals Coal-Based Activated Carbons for the Removal of Sulphur Dioxide via Adsorption

1997 ◽  
Vol 15 (10) ◽  
pp. 803-814 ◽  
Author(s):  
A.M. Youssef ◽  
M.R. Mostafa ◽  
E.M. Dorgham
Keyword(s):  
Activated Carbon ◽  
Low Temperature ◽  
Zinc Chloride ◽  
Sulphur Dioxide ◽  
Activated Carbons ◽  
Textural Properties ◽  
Nitrogen Adsorption ◽  
Carbon Surface ◽  
Steam Activation ◽  
Pore Widening

Zinc chloride-activated carbons and steam-activated carbons were prepared from Maghara coal. The textural properties were determined from low-temperature nitrogen adsorption. Zinc chloride activation is usually associated with the creation of new micropores while steam activation involves pore widening particularly when the percentage burn-off is high. The adsorption of SO2 on steam-activated carbon is high compared with ZnCl2-activated carbons. Steam activation develops surface basic groups which provide chemisorption sites for SO2. The adsorption of SO2 is enhanced in the presence of O2 and water vapour and involves the formation of sulphuric acid in this case. Sulphur dioxide adsorption is related to the chemistry of the carbon surface rather than to the extent of the surface area of the activated carbon.

scholarly journals Comparison of different methods for determination of sodium chloride in cheese

2010 ◽  
Vol 55 (1) ◽  
pp. 65-77 ◽  
Author(s):  
Milos Rajkovic ◽  
Ivana Sredovic ◽  
Zorana Miloradovic
Keyword(s):  
Sodium Chloride ◽  
Standard Addition ◽  
Weight Fraction ◽  
Practical Method ◽  
Solution Concentration ◽  
Indirect Measurement ◽  
Chloride Ions ◽  
Selective Electrode ◽  
The Difference

The content of NaCl (weight fraction of Cl-ions, in %) was analysed in different cheeses, which were bought in supermarkets, and made by domestic manufacturers. Sodium chloride in cheese samples was analysed after the extraction of chloride by nitric acid solution. Concentration of chloride ions was potentiometricly determined, with the chloride selective electrode and titrimetricly by Volhard method. According to the results in the analysis of the content of NaCl in %, by different methods it was determined that the share of NaCl in % ranged from 0.66 to 4.43% (determined by potentiometric route) that is from 0.97 to 4.72% (determined by titrimetric route by Volhard method). The difference in received results in different methods is less if the share of NaCl, in % is higher than 3%. If the share is less than 3%, the difference in results rapidly increases, and the biggest difference is when the share is less than 1%. This analysis was done according to the results received by Volhard method, which is accepted as a standard method. As Volhard method is in connection with cheese resolving by intense oxidation means, azotic acid and potassium permanganate, obligatory in fume board (hood), it is not a practical method. On the other hand, the potentiometric method with usage of the chloride-selective electrode is very simple and gives reliable and reproductive results. In case of a small content of NaCl, in %, higher precision and accuracy of determination by chloride-selective electrode can be obtained by indirect measurement of chloride-ions (by standard addition method).

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