Modification of layer charge in smectites by microwaves

Zemanová, M.; Link, Guido; Takayama, Shuichi; Nüesch, R.; Janek, M.

doi:10.1016/j.clay.2006.01.002

Cited by 26 publications

(15 citation statements)

References 23 publications

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“…For example, it is well known that exchangeable Li can migrate within the smectite structure. However, this process occurs under dry heating only, as shown by Zemanova et al (2006). In case of Li migration, the final location of Li (ditrigonal cavities/vacant octahedra) depends on the crystal chemistry of smectite (i.e., occurrence of octahedral vacancies, negative charge value and distribution.…”

Section: Isotope Fractionation Factorsmentioning

confidence: 96%

Quantifying Li isotope fractionation during smectite formation and implications for the Li cycle

Vigier

Decarreau

Millot

et al. 2008

Geochimica et Cosmochimica Acta

286

225

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Section: Isotope Fractionation Factorsmentioning

confidence: 96%

Quantifying Li isotope fractionation during smectite formation and implications for the Li cycle

Vigier

Decarreau

Millot

et al. 2008

Geochimica et Cosmochimica Acta

286

225

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“…The treatment details have been published elsewhere. − Briefly, the procedure includes the removal of carbonates, iron oxides, and organic matter such as humic material and fractionation to a defined particle size. X-ray diffraction and IR analysis proved that the final solid was pure montmorillonite with cation-exchange capacity equal to 0.95 ± 0.04 mmol/g . The Na form of montmorillonite was used in dispersion to prepare solid samples with different molar ratios of exchangeable Li + to Na + cations.…”

Section: Methodsmentioning

confidence: 99%

Fluorescence Dynamics of Coumarin C522 on Reduced-Charge Montmorillonite in Aqueous Dispersion

Žitňan¹,

Szöcs²,

Janek³

et al. 2009

Langmuir

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Solvation is an important phenomenon, especially in association with heterogeneous phase interactions. Coumarin C522, C(14)H(12)NO(2)F(3), is used as a fluorophore probe to study the interaction between coumarin and a reduced-charge montmorillonite (RCM) surface. Such hydrophilic and hydrophobic interactions are of interest for sorption processes in confined environments. The prepared RCM series with 0.00, 0.12, 0.26, 0.43, 0.66, and 0.97 Li(+) molar fractions provide different surface charges. The aqueous dispersion of the C522/water/RCM system is studied by using steady-state and time-resolved fluorescence spectroscopies. Both the Stokes shift and the dynamics of the solvation process varied as a function of surface charge. Steady-state fluorescence spectroscopy reveals that the C522 Stokes shift varies from 5,115 cm(-1) for the 0.00 Li(+) molar fraction to 3,988 cm(-1) for the 0.97 Li(+) molar fraction. Time-resolved fluorescence spectroscopy determines that the decay time T((1)) varies from 1.0 ps for the 0.00 Li(+) molar fraction to 3.6 ps for the 0.97 Li(+) molar fraction. Within the range of a few picoseconds, the dynamics of the water solvation shell may be described with H-bond rearrangement, modified with the different RCM surface charges. Two models illustrating the interactions between C522 and RCM in water are proposed which qualitatively describe the dynamics. To the best of our knowledge, this experiment is the first measurement of solvation dynamics on a montmorillonite structure surface using ultrafast laser fluorescence spectroscopy.

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“…When the microwave is full powered, the Ag-MMT with the highest silver probably within a few minutes of the treatment [19] , the irradiation time of the microwave-assisted ion exchange reaction is much shorter than the conventional procedures ( > 24 h). The effect of the microwave irradiation time on the Ag content of Ag-MMT is shown in Figure 2 .…”

Section: The Influence Of Microwave Irradiation Powermentioning

confidence: 98%

Preparation and characterization of antibacterial silver loaded montmorillonite under microwave irradiation

Tian

Zhang

Song

et al. 2013

Science and Engineering of Composite Materials

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Silver loaded montmorillonite (Ag-MMT) was prepared by ion exchange reaction under microwave irradiation. The effects of microwave irradiation time, AgNO 3 concentration, and microwave power on the silver content of Ag-MMT were investigated using the Volhard method. The time of ion exchange reaction was found to be greatly shortened under microwave irradiation. The most suitable reaction condition was in 0.2 m AgNO 3 under 100 % microwave power irradiation for 4 min, and the silver content was determined and was found to be 1.23 wt % . The results of the Fourier transform infrared spectrum (FT-IR) and Ag + release tests confirmed the successful loading of silver and its good slow-release property. The X-ray diffraction (XRD) patterns and ultraviolet-visible (UV-vis) spectra proved the existence of metallic Ag nanoparticles. The Ag-MMT showing a large inhibition zone, high inhibition ratio, and low minimum inhibitory concentration (MIC) value against Staphylococcus aureus ATCC6535 presented a very good antibacterial property.

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Modification of layer charge in smectites by microwaves

Cited by 26 publications

References 23 publications

Quantifying Li isotope fractionation during smectite formation and implications for the Li cycle

Quantifying Li isotope fractionation during smectite formation and implications for the Li cycle

Fluorescence Dynamics of Coumarin C522 on Reduced-Charge Montmorillonite in Aqueous Dispersion

Preparation and characterization of antibacterial silver loaded montmorillonite under microwave irradiation

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