scholarly journals Study on the Adsorption Behavior between an Imidazolium Ionic Liquid and Na-Montmorillonite

Molecules ◽  
2019 ◽  
Vol 24 (7) ◽  
pp. 1396 ◽  
Author(s):  
Jingjing Pei ◽  
Xuesong Xing ◽  
Boru Xia ◽  
Ziming Wang ◽  
Zhihua Luo
Keyword(s):  
Ionic Liquid ◽  
Cation Exchange ◽  
Ph Value ◽  
Exchange Capacity ◽  
Adsorption Behavior ◽  
Exchangeable Cation ◽  
Imidazolium Ionic Liquid ◽  
Cationic Group ◽  
Adsorption Amount ◽  
Thermal Stability Of

Interactions between 1-butyl-3-methylimidazolium tetrafluoroborate (IL), an ionic liquid, and Na-montmorillonite (Na-MMT) were studied under different kinetic conditions to investigate the adsorption behavior of IL by Na-MMT. The adsorption of IL by Na-MMT was rapid, with a fast rate, reaching a capacity of 0.43 mmol/g, lower than Na-MMT’s cation exchange capacity (CEC) of 0.90 mmol/g. Meanwhile, the highest adsorption rate occurred at the IL concentration of 1000 mg/L. The exchangeable cation of Na-MMT could not be completely substituted by the cation group of IL regardless of the IL concentration. Stoichiometric desorption experiments confirmed that the cation exchange was the dominating adsorption mechanism for the IL adsorption by Na-MMT. The pH value of the solution between 2 and 11 had a negligible effect on the adsorption amount of IL by Na-MMT. The cation group of IL interacted into the interlayer of Na-MMT successfully, resulting in the change in the wettability of Na-MMT. A bilayer formation of the cationic group should occur in the interlayer of the modified Na-MMT and the configuration of IL was dependent on the adsorption amount of IL. Furthermore, the thermal stability of the modified Na-MMT was also dependent on the adsorption amount of IL.

scholarly journals THE EFFECT OF CHLORO ACETIC ACID CONCENTRATION AND TEMPERATURE REACTION OF CARBOXYMETHYL CHITOSAN FORMATION ON CATION EXCHANGE CAPACITY AND THERMAL STABILITY

2018 ◽  
Vol 10 (1) ◽  
pp. 31
Author(s):  
Candra Purnawan ◽  
Edi Pramono ◽  
Purwanto Purwanto
Keyword(s):  
Thermal Stability ◽  
Acetic Acid ◽  
Cation Exchange ◽  
Acid Concentration ◽  
Cation Exchange Capacity ◽  
Exchange Capacity ◽  
Carboxymethyl Chitosan ◽  
Temperature Reaction ◽  
Acetic Acid Concentration ◽  
Thermal Stability Of

<p>The research on the effect of chloro acetic concentration and temperature reaction of carboxymethyl chitosan formation on cation exchange capacity and thermal stability of polymer have been done. Carboxymethyl chitosan was synthesized by reaction of chitosan and chloro acetic acid with NaOH as catalyst. Polymer was characterized by Fourier Transform Infrared Spectrofotometer, cation exchange capacity test, and thermal analysis with thermogravimetric method. Carboxymethyl chitosan has strong FTIR adsorption of carboxyl group (-COO-) in 1606,70 cm<sup>-1</sup> and 1444,68 cm<sup>-1</sup>. The increasing of chloro acetic acid concentration and reaction temperature decreased cation exchage capacity and changed thermal stability of polymer.</p>

scholarly journals THE EFFECT OF CHLORO ACETIC ACID CONCENTRATION AND TEMPERATURE REACTION OF CARBOXYMETHYL CHITOSAN FORMATION ON CATION EXCHANGE CAPACITY AND THERMAL STABILITY

2016 ◽  
Vol 10 (1) ◽  
pp. 31
Author(s):  
Candra Purnawan ◽  
Edi Pramono ◽  
Purwanto Purwanto
Keyword(s):  
Thermal Stability ◽  
Acetic Acid ◽  
Cation Exchange ◽  
Acid Concentration ◽  
Cation Exchange Capacity ◽  
Exchange Capacity ◽  
Carboxymethyl Chitosan ◽  
Temperature Reaction ◽  
Acetic Acid Concentration ◽  
Thermal Stability Of

<p>The research on the effect of chloro acetic concentration and temperature reaction of carboxymethyl chitosan formation on cation exchange capacity and thermal stability of polymer have been done. Carboxymethyl chitosan was synthesized by reaction of chitosan and chloro acetic acid with NaOH as catalyst. Polymer was characterized by Fourier Transform Infrared Spectrofotometer, cation exchange capacity test, and thermal analysis with thermogravimetric method. Carboxymethyl chitosan has strong FTIR adsorption of carboxyl group (-COO-) in 1606,70 cm<sup>-1</sup> and 1444,68 cm<sup>-1</sup>. The increasing of chloro acetic acid concentration and reaction temperature decreased cation exchage capacity and changed thermal stability of polymer.</p>

scholarly journals Lab Study on the Effect of Cation Exchange Capacity on Slurry Performance in Slurry Shields

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
By Pinghe Sun ◽  
Binkui Zhao ◽  
Han Cao ◽  
Jingyuan Wang ◽  
Dingqiang Mo ◽  
...  
Keyword(s):  
Cation Exchange ◽  
Rheological Properties ◽  
Cation Exchange Capacity ◽  
Ph Value ◽  
Field Work ◽  
Exchange Capacity ◽  
Rheological Parameters ◽  
Flow Index ◽  
Linear Change ◽  
Design Requirements

Ion stabilizers can enhance the reinforcement slurry effect on the wall and stabilize the wall actively in slurry shields. This paper presents different cation exchange capacities obtained by changing the content of the ion stabilizer (1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, 5.0%, 5.5%, and 6.0%) in slurry associated with the basis of the existing slurry formula through the laboratory tests. In order to study the effect of the cation exchange capacity on the performance of slurry properties, the rheological properties of the slurry are analyzed and evaluated by the power law model. Results indicate that the cation exchange capacity of the slurry decreases first and then increases with the increase of the ion stabilizer content. When the content of the ion stabilizer is maintained at 3.50%, the cation exchange capacity reaches the minimum value of 2.92. The filtration volumes, pH values, and rheological parameters of the slurry also indicate an obvious linear change with the change of the cation exchange capacity. The minimum filtration volume is 9.70 mL/30 min when the ion stabilizer content reaches 3.50%. However, the pH value reaches the maximum, that is, 11.34 which is changed from 10, and the change could be considered as a constant value in the field work. When the cation exchange capacity increases, the continuity of polymer structure in the slurry decreases first and then increases, the flow index and consistency coefficient are located within a reasonable range, and the rheological properties of the slurry meet the design requirements of the standards.

scholarly journals Interactions of bentonite with metal and concrete from the FEBEX experiment: mineralogical and geochemical investigations of selected sampling sites

Clay Minerals ◽  
2018 ◽  
Vol 53 (4) ◽  
pp. 745-763 ◽  
Author(s):  
S. Kaufhold ◽  
R. Dohrmann ◽  
K. Ufer ◽  
F. Kober
Keyword(s):  
Cation Exchange ◽  
Large Scale ◽  
Test Site ◽  
Exchange Capacity ◽  
Metal Corrosion ◽  
Special Role ◽  
Exchangeable Cation ◽  
Bentonite Buffer ◽  
The Face ◽  
High Level

ABSTRACTThe FEBEX experiment, a full-scale, high-level radioactive waste repository test, ran for ~18 years and hence is the longest-running disposal test to date. The test consisted of a heater emplaced in an envelope of compacted bentonite at the Grimsel test site, Switzerland. The water content of the bentonite was somewhat lower near the heater and increased towards the granite. This phenomenon probably led to gradients in the exchangeable cation population at various locations within the bentonite buffer. The cement (shotcrete) bentonite interface of one block was characterized by a thin (0.1–1.0 mm) reaction zone in which bentonite constituents, carbonates and sulfates occurred. Cation exchange and a slight decrease of the cation exchange capacity were observed near the heater. Oxic corrosion was observed predominantly at the bentonite/steel liner interfaces, pointing towards a role of air entrapped between the liner and heater during emplacement. At the liner surface, intimate intergrowth of bentonite constituents, metal and corrosion products was observed. At the face of the heater, the bentonite blocks were in direct contact with the heater surface without any signs of metal corrosion. Instead, a significant increase in the Mg content was recorded, which is in agreement with previous large-scale disposal tests. The FEBEX experiment proved that the Mg increase and corrosion were independent processes. The increase in Mg may be explained by the formation of trioctahedral domains or the precipitation of neoformed silicates. For the first time, however, brucite was identified as an additional phase that formed at the metal/bentonite interface, pointing towards a special role for Mg mobility in the bentonite barrier.

Mineralogical investigations of the first package of the alternative buffer material test – II. Exchangeable cation population rearrangement

Clay Minerals ◽  
2013 ◽  
Vol 48 (2) ◽  
pp. 215-233 ◽  
Author(s):  
R. Dohrmann ◽  
S. Olsson ◽  
S. Kaufhold ◽  
P. Sellin
Keyword(s):  
Cation Exchange ◽  
Large Scale ◽  
Vertical Direction ◽  
Exchange Capacity ◽  
Maximum Temperature ◽  
Exchangeable Cation ◽  
Water Tank ◽  
Material Test ◽  
Buffer Material ◽  
Iron Tube

AbstractBentonites are candidate materials for the encapsulation of radioactive waste. In the ‘Alternative Buffer Material test’ (ABM), compacted ring-shaped blocks of eleven different buffer materials (mainly bentonites) were packed vertically on top of each other with an iron tube as heater in the centre. These buffer materials started with various exchangeable cation populations (ECpopulation). The first ‘ABM package’ was terminated 28 months after installation and the bentonites had been exposed to the maximum temperature (130°C) for about one year. The aim of the present study is first: to describe modification of the cation exchange population, and second to understand the influence of the groundwater on cation exchange at different scales. No significant horizontal variation of any exchangeable cation (EC) was detected between 1 and 7 cm distance from contact with the iron tube. Large total differences of the ECpopulations, however, were observed for the individual blocks after the field experiment (n = 21 blocks) with respect to the composition of the reference materials. The average cation exchange capacity (CEC) values of the analysed bentonites (n = 9 blocks) decreased by 5.5 meq/100 (1.1 – 8.8 meq/100 g) after the experiment. Exchangeable Na+ and Mg2+ decreased on average, whereas Ca2+ increased. This trend was pronounced in the top region of the parcel (upper seven blocks). Although most changes occurred on the large scale of the whole test parcel, small but important changes were also recorded in the vertical direction on the centimetre scale. The observed differences cannot be explained assuming simply that a bentonite reacts only with neighbouring blocks, which would mean that the system was more or less closed. The differences are much larger and the only conclusion from this observation is that the whole package seems to be influenced by the groundwater which was added from a water tank at the experiment site, enabling at least partial equilibration between the different blocks.

Superior cellulose-protective effects of cosolvent during enhanced dissolution in imidazolium ionic liquid

Holzforschung ◽  
2016 ◽  
Vol 70 (6) ◽  
pp. 519-525 ◽  
Author(s):  
Juan Tao ◽  
Takao Kishimoto ◽  
Satoshi Suzuki ◽  
Masahiro Hamada ◽  
Noriyuki Nakajima
Keyword(s):  
Ionic Liquid ◽  
Degree Of Polymerization ◽  
Regenerated Cellulose ◽  
Cellulose Ii ◽  
Protective Effects ◽  
Imidazolium Ionic Liquid ◽  
Amorphous Cellulose ◽  
Enhanced Dissolution ◽  
Characteristic Features ◽  
Thermal Stability Of

Abstract To improve the solubility of cellulose at lower temperatures, several polar organic solvents were examined as cosolvents in imidazolium ionic liquid (IL). All tested cosolvents increased the solubilization efficiency of ILs at lower temperatures. Among these, N-methylimidazole, N-methyl-2-pyrrolidone, and dimethyl sulfoxide (DMSO) were notably efficient; in case of Avicel the solubility was increased, with 12–15% cellulose dissolution in 1-allyl-3-methylimidazolium chloride ([Amim]Cl) at 30°C. IR spectra of the regenerated celluloses from IL/cosolvent systems showed characteristic features of cellulose II and/or amorphous cellulose. Thermogravimetric analyses showed significantly higher thermal stability of regenerated cellulose from [Amim]Cl/DMSO compared with that without DMSO. Moreover, dimethylacetamide (DMAc) increased the solubility of filter paper pulp in 1-ethyl-3-methylimidazolium acetate ([Emim]OAc), with 12% pulp dissolution at 30°C. No decrease in the degree of polymerization (DP) of cellulose was observed with [Emim]OAc/DMAc, whereas 8–9% DP decrease was observed with [Emim]OAc, even at 30°C. These results indicate that some cosolvents including DMSO and DMAc increase solubilization efficiency and have superior cellulose-protective effects during enhanced dissolution in ILs.

scholarly journals Evaluation of the lime requirement of tropical soils in terms of other soil characteristics

1969 ◽  
Vol 36 (2) ◽  
pp. 155-160
Author(s):  
M. A. Lugo López ◽  
F. Abruña ◽  
J. Roldán
Keyword(s):  
Cation Exchange ◽  
Clay Mineral ◽  
Cation Exchange Capacity ◽  
Ph Value ◽  
Organic Matter Content ◽  
Clay Content ◽  
Tropical Soils ◽  
Exchange Capacity ◽  
Matter Content ◽  
Significant Regression

The quantity of limestone required to bring the pH of various acid Puerto Rican soils to 6.5 was investigated and found to vary from several hundred to several thousands pounds per acre. To investigate the relation of clay-mineral type, clay content, cation-exchange capacity, organic-matter content, and pH to lime requirement, these properties were determined for several soils. A highly significant regression of lime requirement on pH was obtained which can be expressed by the equation: Y = 18.39 — 3.196 X, where Y is the lime requirement and X is the pH value. Multiple regressions including other factors did not significantly increase the variability which could be explained on terms of the first regression. Further analysis were made by arranging the data according to the predominant clay mineral. For kaolinitic soils highly significant correlations were obtained between lime requirement and either pH or cation exchange capacity. The regressions were: (a) Y = 15.26 — 2.632 pH, and (b) Y = 3.048 + 0.5774 (cation-exchange capacity), where Y is the lime requirement. A regression of lime requirement on both factors did not significantly increase the variability explained by the second equation. No significant regressions were obtained for beidellitic soils.

Changes in effective cation exchange capacity and exchangeable aluminum with soil pH in lime-amended field soils

Soil Research ◽  
1992 ◽  
Vol 30 (2) ◽  
pp. 177 ◽  
Author(s):  
Z Hochman ◽  
DC Edmeades ◽  
E White
Keyword(s):  
Cation Exchange ◽  
Linear Relationship ◽  
Soil Ph ◽  
Cation Exchange Capacity ◽  
Ph Value ◽  
Exchange Capacity ◽  
Exchangeable Cations ◽  
Acidic Soils ◽  
Hydrogen Ion Concentration ◽  
Wide Range

Eleven acidic soils from northern N.S.W., having a wide range of values for ECEC, A1 and soil organic carbon (%C), were treated in the field with five rates of lime. The relationships between soil pH and the effective cation exchange capacity (ECEC), and between pH and exchangeable aluminium (Al), were investigated for the top 10 cm of these soils. Increases in the total exchangeable cations (TEC) calculated as ECEC-Al, were shown to be madelup almost entirely by increases in exchangeable calcium. There were no consistent changes in the amount of exchangeable magnesium, potassium or sodium due to liming these acidic soils. Formulae used to predict changes in A1 and ECEC with pH in the 'Lime-it' model were tested and modified on the 11 soils from northern N.S.W. A strong linear relationship was observed in each soil between Al and pH (transformed to hydrogen ion concentration x 103). The slope of this relationship (SALs) can be predicted from the pH and A1 values of unlimed soils. Strong linear relationships were also observed between pH and TEC, for each of the 11 soils. The SL, (the slope of the linear relationship TEC/pH for any soil 's') was shown by multiple regression analysis to be a function of TECi/pHi (where TECi is the sum of exchangeable cations of unlimed soil 's'; and pHi is the pH value of unlimed soil 's'), %C of the unlimed soil, and SALs. By using the measured values of pH, ECEC, Al and %C of unlimed soils, the values of Al, and TEB can be predicted for any pH value that may be measured (or predicted) after liming. The predictive relationships developed on N.S.W. soils were tested against independent data from New Zealand. The results confirmed the Al/pH predictions (R2 = 0.955), while the TEC/pH predictions were less well matched (R2= 0.62) possibly due to unusual clay mineralogy or organic matter fractions of 3 of the 18 soils tested.

Chemical and charge characteristics of kaolinitic soils of south-east Queensland

Soil Research ◽  
1983 ◽  
Vol 21 (3) ◽  
pp. 271 ◽  
Author(s):  
JO Skjemstad ◽  
AJ Koppi
Keyword(s):  
Cation Exchange ◽  
Surface Area ◽  
Cation Exchange Capacity ◽  
Negative Charge ◽  
Ph Value ◽  
Divalent Cations ◽  
Active Surface ◽  
Exchange Capacity ◽  
Oxide Surface ◽  
Oxalate Extraction

Cation exchange capacity at field pH and net negative charge at pH 8.5 of 39 kaolinitic soils were studied in relation to surface area and other soil characteristics. All soils exhibited an anion exchange capacity at field pH, but this was very low compared with cation exchange capacity. Little evidence could be found for the presence of amorphous aluminium or silica, or short-range order alumino-silicates on the basis of acid oxalate-extraction, in contrast to Tiron extraction. All samples had significant permanent negative charge as deduced using the method of Gillman and Uehara, in addition to pHdependent charge. The former was strongly related to the exchangeable divalent cations, and this may explain the great variation in base saturation observed. Most of the charge in these soils is derived from the small poorly crystalline kaolins, although at high pH oxalate-extractable iron contributes significantly to the negative charge. Based on the results for those soils containing less than 5% iron oxide, surface area determined by ethylene glycol is linearly related to the net negative charge at pH 8.5. The average surface charge density on the soils containing <5% hematite and goethite measured at this pH value is 0.9 nm2/charge. Hematite and goethite show much lower negative charge densities and effectively dilute the active surface.

Sign in / Sign up

Export Citation Format

Share Document