23Na and7Li NMR study ofNitellacell walls before and after an ion-induced loss of the cationic exchange capacity

1994 ◽  
Vol 45 (8) ◽  
pp. 1077-1084 ◽  
Author(s):  
C. Gillet ◽  
C. Labille ◽  
J.B. Nagy
Keyword(s):  
Exchange Capacity ◽  
Nmr Study ◽  
Before And After ◽  
Cationic Exchange

Synthesis and Characterization of Silver-Histidine Complex Doped Montmorillonite Antibacterial Agent

2012 ◽  
Vol 510 ◽  
pp. 757-761 ◽  
Author(s):  
Shu’e Duan ◽  
Yun Hui Zhai ◽  
Ying Juan Qu
Keyword(s):  
Antibacterial Agent ◽  
Sea Water ◽  
Antibacterial Activities ◽  
Exchange Capacity ◽  
Salt Tolerant ◽  
X Ray Diffraction ◽  
Ion Exchange Reaction ◽  
Cationic Exchange ◽  
Loading Amount

In this paper a novel colorless and salt-tolerant silver-histidine complex doped montmorillonite (Na-MMT) antibacterial agent (SHMMT) power was synthesized by ion exchange reaction using silver-histidine complex ion [Ag (his)] + as precursor, and characterized by atomic absorption spectrophotometer (AAS) and power X-ray diffraction (XRD). The antibacterial activities against Pseudoalteromonas carrageenovora were examined by a modified broth dilution test and the plate counting method. The salt-tolerant property was determined by the antibacterial activities of the sea water soaked SHMMT. The results showed that the Ag loading amount of SHMMT powder reached 1.7mmol/g, far more than the cationic exchange capacity (CEC) of Na-MMT. SHMMT powder had high bacterial activity eventhough it was soaked in the sea water for 30 days. 1

scholarly journals Changes in suspension properties of structural modified montmorillonites

Cerâmica ◽  
2001 ◽  
Vol 47 (301) ◽  
pp. 4-8 ◽  
Author(s):  
C. Volzone ◽  
L. B. Garrido
Keyword(s):  
Particle Size ◽  
Structural Disorder ◽  
Physicochemical Characteristics ◽  
Exchange Capacity ◽  
X Ray Diffraction ◽  
Flow Properties ◽  
Flow Curves ◽  
Structural Modifications ◽  
Fine Particle Size ◽  
Cationic Exchange

Rheological changes were found in smectite (Wyoming- and Cheto-type montmorillonites) suspensions after structural modifications. The effect of the particle size and Na+ exchange on the flow curves of 6% wt/wt suspensions of smectites with and without Na2CO3 were examined. Mineralogical, structural and physicochemical characteristics were studied by X-ray diffraction (XRD), infrared spectroscopy (IR), cationic exchange capacity (CEC), Mg2+, Al3+ determinations, particle size distribution and swelling index (SI). Grinding in an oscillating mill modified the particle sizes. The montmorillonite grain size and the structural disorder increased after larger grinding times. The grinding treatment modified the apparent viscosity and the yield stress of the montmorillonite suspensions. The homoionic Na Cheto-type montmorillonite with fine particle size (obtained by grinding) increased the flow properties. Nevertheless, rheological properties were lower than those of suspensions of the Wyoming-type montmorillonite. Montmorillonite-types reacted differently with Na2CO3 additions and this behavior may be related to their structural composition. The Na2CO3 activation improved the flow properties of the original Wyoming-type montmorillonite and after 30 s grinding.

scholarly journals Mineralogical characterization of natural clays from Brazilian Southeast region for industrial applications

Cerâmica ◽  
2017 ◽  
Vol 63 (366) ◽  
pp. 253-262 ◽  
Author(s):  
N. I. Alvarez Acevedo ◽  
M. C. G. Rocha ◽  
L. C. Bertolino
Keyword(s):  
Specific Surface ◽  
Clay Fraction ◽  
Exchange Capacity ◽  
Size Analysis ◽  
Mineralogical Characterization ◽  
Southeast Region ◽  
Pore Size Analysis ◽  
Two Samples ◽  
Natural Clays ◽  
Cationic Exchange

Abstract Characterization studies of clays are often performed to identify possible markets for these materials. Bearing this in mind, two samples of natural clays from the Southeast region of Brazil were studied. Conventional techniques of characterization were used. Granulometric analysis and determination of cationic exchange capacity of these clays were also performed. Nitrogen adsorption-desorption measurements were used to determine the Brunauer-Emmett-Teller specific surface area, and Barrett-Joyner-Halenda and t-plot pore size analysis were carried out. The results obtained were similar for the two clays. Both present high clay fraction (above 80 wt%) composed of illite, kaolinite and quartz minerals. Stratified illite-smectite structures were also observed. Traces of calcite were detected in one of the clay samples, while traces of montmorillonite were observed in the other sample. These results were corroborated by the low cationic exchange capacity values obtained for both clays. These clays showed good adsorptive properties, evidenced by their specific surface areas, with predominantly mesoporous structures and slit-like pores. According to their features, these clays have potential use as adsorbents to replace more expensive materials due to their easy availability and low cost.

scholarly journals The Identification of Electrolyte Property of Humus-Contained Andosol Soil Using Cu-Zn Electrodes

2020 ◽  
Vol 3 (2) ◽  
pp. 71
Author(s):  
Irvan Maulana Firdaus ◽  
Diva N.M.D. Masyitoh ◽  
Tharra A.N. Azizah ◽  
Febiyanto Febiyanto
Keyword(s):  
Single Cell ◽  
Cell System ◽  
Exchange Capacity ◽  
Waste Materials ◽  
Humus Substance ◽  
Electrode Area ◽  
Electrode Distance ◽  
Cationic Exchange ◽  
Cu And Zn

<p><em>This study investigated the electrolyte property of humus-contained andosol soil using Volta cell. The electrodes that are used were Cu and Zn for cathode and anode, respectively. This research was done by varying electrode area and distance between Cu and Zn electrodes. The varied electrode area was 20, 30, and 40 cm<sup>2</sup>, whereas the electrode distance was 3, 4, and 5 cm. Then, the current and voltage profiles of Volta cell system were measured using a digital multimeter. The result showed that humus-contained andosol soil has an electrolyte property. Electrolyte property of andosol soil might be due to the humus substance that has a high cationic-exchange capacity. Besides, it showed that the increase of the electrode area, the current and voltage were increased gradually. In contrast, the increase in current and voltage could be found by the decrease of electrode distance. In addition, the use of 24-Volta cells system enhancing current and voltage compared to a single cell. It suggests that the increase of current and voltage was relatively proportional to the number of Volta cell. Therefore, this research can be a reference for the identification of electrolyte property of natural or waste materials.</em></p>

scholarly journals COMPOSITE OF CHITOSAN VANILIN / SULFONATED POLYSTYRENE AS POLYMER ELECTROLYTE MEMBRANES : CATIONIC EXCHANGE CAPACITY, SWELLING DEGREE AND THERMAL PROPERTIES

2016 ◽  
Vol 10 (2) ◽  
pp. 116
Author(s):  
Edi Pramono ◽  
Candra Purnawan ◽  
Yuniawan Hidayat ◽  
Jati Wulansari ◽  
Sayekti Wahyuningsih
Keyword(s):  
Thermal Properties ◽  
Composite Membranes ◽  
Exchange Capacity ◽  
Membrane Composition ◽  
Sulfonated Polystyrene ◽  
Swelling Degree ◽  
Electrolyte Membranes ◽  
Three Stages ◽  
Cationic Exchange

Research on the preparation and characterization of sulfonated polystyrene (PST) /chitosan vanillin (KV) composite as electrolyte membranes has been conducted in order to investigate the effect of PST and KV composition  to its chemical and physical properties. Polystyrene was modified by sulfonation reaction to produces PST<strong>, </strong>meanwhile chitosan was modified by schift base reaction to produces KV. The composite membranes were prepared by casting method and were characterized in order to identify the functional groups contained in the composite, the cation exchange capacity (CEC), the Swelling Degree (SD), the thermal properties and the morphology. The peak of imine vibration in the FTIR spectrum indicates that the chitosan vanilin was succesfully synthesized. Meanwhile, the peak of sulfonate vibration indicates the product of sulfonation on polystyrene. The result of CEC analysis shows that the addition of sulfonate groups on polystyrene and the addition of phenolic groups on chitosan increase the CEC value. The increasing of PST and KV concentration in membrane enhance the CEC value. However, the increasing of PST concentration in membrane composition even decrease the Swelling Degree of membranes. Meanwhile, the increasing of KV concentration increase the swelling degree of membranes. Thermal analysis shows that the thermal decomposition of membranes occurs in three stages i.e. the dehydration of water molecules, the degradation of the subtituen groups and the plasticizer and the degradation of the back bone of chitosan and polystyrene.

X-ray photoelectron spectroscopic analysis of halloysites with different composition and particle morphology

Clay Minerals ◽  
1992 ◽  
Vol 27 (4) ◽  
pp. 413-421 ◽  
Author(s):  
M. Soma ◽  
G. J. Churchman ◽  
B. K. G. Theng
Keyword(s):  
Photoelectron Spectroscopy ◽  
Cation Exchange Capacity ◽  
Spectroscopic Analysis ◽  
Surface Composition ◽  
Particle Morphology ◽  
Exchange Capacity ◽  
Surface Layers ◽  
X Ray ◽  
Fe Content ◽  
Before And After

AbstractThe surface composition of some halloysites with different particle morphology has been investigated by X-ray photoelectron spectroscopy (XPS) before and after removal of external Fe. The Fe(III) 2p3/2 binding energy of external Fe is appreciably smaller than that of structural Fe. Particle morphology is influenced by structural Fe content. The long-tubular halloysite has very little surface Fe, and its concentration tends to increase with the proportion of non-tubular particles in the samples. The spheroidal sample contains the most structural Fe which, however, does not appear to influence particle shape directly. Study by XPS indicates that Fe substitutes for Al in octahedral positions in approximately 1 : 2 proportion. As a result, an increase in octahedral vacancies and cation exchange capacity would be predicted. Further, halloysite layers within a crystal are generally inhomogeneous in composition. Built up like “onion skins”, the surface layers would either be enriched or depleted in Fe depending on the chemical environment in which crystal growth occurs.

ESTIMATION OF THE INORGANIC AND ORGANIC pH-DEPENDENT CATION EXCHANGE CAPACITY OF THE B HORIZONS OF PODZOLIC AND BRUNISOLIC SOILS

1968 ◽  
Vol 48 (1) ◽  
pp. 53-63 ◽  
Author(s):  
J. S. Clark ◽  
W. E. Nichol
Keyword(s):  
Organic Matter ◽  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Acid Soils ◽  
Exchange Capacity ◽  
Hydrous Oxides ◽  
Before And After ◽  
Ph Dependent ◽  
The Difference ◽  
Wyoming Bentonite

Heating in hydrogen peroxide, dilute oxalic acid, and dilute aluminum oxalate did not change the effective cation exchange capacity (CEC) or the pH-7 CEC of Wyoming bentonite and Alberni clay soil containing excess Al(OH)x. This indicated that treatment of soils with H2O2 to oxidize organic matter and the possible production of oxalates during oxidation did not change the CEC values of the inorganic fraction of soils even if some clay exchange sites were blocked by hydrous oxides of Al.With soils of pH less than approximately 5.4, oxidation of organic matter did not change the effective CECs although the pH-7 CEC values were decreased. Thus, organic matter in acid soils appeared to have little or no effective CEC. Because of this and the negligible effect of H2O2 oxidation on the CEC values of clays, the difference of the pH-7 CEC of soils before and after H2O2 oxidation provided a simple means of estimating the amount of organic pH-dependent CEC in acid soils.The amount of organically derived pH-dependent CEC was determined in a number of soils by means of peroxide oxidation. The technique provided a useful indication of the quantities of sesquioxide–organic matter complexes accumulated in medium- and fine-textured soils.

Preparation of Organovermiculite for Adsorption of Organic Compounds

2012 ◽  
Vol 727-728 ◽  
pp. 1451-1456
Author(s):  
Andréa Lopes Silva ◽  
Francisco Kegenaldo Alves de Souza ◽  
Gelmires Araújo Neves ◽  
Romualdo Rodrigues Menezes ◽  
Hélio Lucena Lira ◽  
...  
Keyword(s):  
Organic Compounds ◽  
Organic Pollutants ◽  
Organic Contaminants ◽  
Exchange Capacity ◽  
Natural Clay ◽  
Modified Clay ◽  
Organically Modified ◽  
Dimethyl Ammonium ◽  
Cationic Exchange ◽  
Clay Materials

Organically modified clay minerals are widely used as sorbents for hydrophobic organic compounds e.g., organic pollutants treatment from water solutions. Natural clay materials are hydrophilic and therefore they are not efficient sorbents for organic compounds. Intercalations of natural clay materials, with organic cations, with quaternary ammonium groups may become these clays hydrophobic. Vermiculite is the mineralogical name given to hydrated laminar magnesium-aluminum-iron silicate; this natural clay was modified and used for the production of organically modified clay (organovermiculite), with the purpose of its use in removing organic contaminants. The organovermiculite was prepared using different concentrations of distearyl dimethyl ammonium chloride (praepagen) based on cationic exchange capacity of the clay. It was evident from the X-ray diffraction that the salt was incorporated to the clay structure confirming its organophilization and through the Foster swelling test it was observed the affinity between the organic pollutants and the organovermiculite.

scholarly journals Selected elements cations exchange in acidic medium on sorbents surface based on modified brown coal

2017 ◽  
Vol 33 (1) ◽  
pp. 139-150 ◽  
Author(s):  
Agata Stempkowska ◽  
Piotr Izak ◽  
Joanna Mastalska-Popławska
Keyword(s):  
Hydrochloric Acid ◽  
Chemical Modification ◽  
Brown Coal ◽  
Elevated Temperatures ◽  
Exchange Capacity ◽  
Distilled Water ◽  
Desorption Process ◽  
Second Stage ◽  
Before And After ◽  
Static Conditions

Abstract Studies on the sorption and desorption of selected Na+, Ca2+, Mg2+, Mn2+, Cu2+ and Cr3+ cations by materials based on modified brown coal were carried out. The chemical modification of the sorbent material consisted of grinding involving different inorganic substances and organic polymers. Samples were subjected to chemical modification at elevated temperatures for several hours. For comparative purposes, as apart from brown coal, pure humic acids are known for the highest cations exchange capacity, samples of brown coal before and after purification were also analyzed. The ion capacity was determined under static conditions, measuring the difference in the concentration of cations in the sorbent before and after sorption and then after rinsing the sorbent with distilled water (A), and after the desorption process with hydrochloric acid (B). Studies have shown that sorbents based on modified brown coal have rather significant exchange capacities in the range of 270-450 meq/100 g for the first stage and 90-200 meq/100 g for the second stage. It was also found that purified humic acid (450-200 meq/100 g) has the highest exchange capacity and modified brown coal obtained at 250°C has the lowest. The measurement of desorption showed that approximately 10% of the cations are already leached by distilled water and the residue is desorbed under the influence of 10% hydrochloric acid, but the total amount of cations is compatible with the measurement process of the second stage. The sorption affinity to various cations is different. In the case of the sorption measurements, modified sorbents show the highest sorption affinity with respect to calcium, while the unmodified raw brown coal with respect to chromium. The next stage of the measurement showed that the valence of the cation has the highest impact on the sorption affinity.

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