A new family of fast ion conductor-montmorillonites

Fan, Yi; Wu, Hui

doi:10.1016/s0167-2738(96)00446-8

Cited by 20 publications

(15 citation statements)

References 7 publications

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“…Garcfa et al [8] found a linear dependence of log(or) with the water partial pressure for Na § and Li+-montmorillonite at 25 ~ which was divided into two linear regions with different slopes. A linear behaviour was also reported by Fan et al [9] for Na +-and Li+-montmorillonite. They did not, however, report two separate linear regions.…”

Section: Introductionsupporting

confidence: 79%

“…An increase of log(r with the water content of the clay or with the relative humidity has been reported [6][7][8][9]. Garcfa et al [8] found a linear dependence of log(or) with the water partial pressure for Na § and Li+-montmorillonite at 25 ~ which was divided into two linear regions with different slopes.…”

Section: Introductionmentioning

confidence: 99%

“…Zhu et al [10] reported a decrease in conductivity with increasing temperature from 90 up to about 200 ~ then an increase up to 610 ~ As to the mechanism of conductivity observed in clay minerals, usually protons are considered to be the most mobile charge carrying species (Calvet [7], Boutehala [2]). On the other hand, Fan et al [9] emphasized the determining role that interlayer cations play in the conduction process and question the main role of protons. Zhu et al [10] expected a combined conductivity of protons and interlayer cations.…”

Section: Introductionmentioning

confidence: 99%

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Electrochemical measurements on clay minerals for possible sensor applications

Fokkens¹,

Schäf²,

Guth

1999

Ionics

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Abstract. Natural clays were characterized by XRD, TGA and SEM/EDX, then pressed to pellets and analyzed by impedance measurements under various defined gas compositions and temperatures. From the Nyquist plot, conductivity values were calculated for the different clay samples. A strong dependence of the conductivity on the water vapour concentration at low temperatures was found for all investigated clay samples. Partial substitution of water by methanol led to a decrease in conductivity at low temperatures, confirming the essential role water plays in the conductivity mechanism at these temperatures. Increasing the temperature resulted in a decrease in conductivity, until a turn-over point was reached. Beyond this temperature an Arrhenius behaviour was observed, suggesting a change in the conductivity mechanism.

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Section: Introductionsupporting

confidence: 79%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Electrochemical measurements on clay minerals for possible sensor applications

Fokkens¹,

Schäf²,

Guth

1999

Ionics

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“…The band at 3624 cm -1 is absent in the MMTPEO. This is due to the interaction between the ether-oxygen of PEO segments and the free -OH groups of clay layers via hydrogen bonding [26]. This can be seen as the disappearing of the band at 3624 cm -1 and appearing of well-transformed peak at 3447 cm -1 .…”

Section: Ionic Conductivity Studiesmentioning

confidence: 96%

Ionic Conductivity of poly(ethylene oxide) (PEO)-montmorillonite(MMT) Nanocomposites Prepared by Intercalation from Aqueous Medium

2006

Int J Electrochem Sci

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Solid electrolyte systems, especially solid polymer electrolyte systems have been widely used as potential technological applications in secondary energy sources and electrochromic devise nowadays. The ion-transport behavior of these systems is to be well understood to enhance electronic properties. It is apparent that these materials show ionic conductivity when ionic salts are dissolved in them. The mechanism of ionic mobility is still controversial. We have made an attempt to address these problems by choosing montmorillonite/poly(ethylene oxide)(PEO)/cation as a model system and systematically understanding the bonding, intercalation and ionic conductivity by Fourier Transformed Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD) and AC-Impedance Spectroscopy respectively. The systems of Na + -montmorillonite, Li + -montmorillonite, and Li + -montmorillonite-PEO are characterized. The XRD data showed that the Na + -montmorillonite has a d-spacing of 15.49 Å attributing to the presence of Na + and two water layers within interlayers of MMT at room temperature. The removal of water brings the d-spacing to 9.97 Å. Solution intercalation of PEO into Li + -montmorillonite results in the enhancement of d-spacing up to 18.73 Å which readily takes up water, enhancing the d-spacing to 23.33 Å. These results show clearly that PEO is readily intercalated in montmorillonite at a composition of 6 wt% PEO, and leaching of PEO at successive washing takes place below 6 wt% of PEO. In the FT-IR spectrum of montmorillonite two types of ν (OH) are seen; isolated ν (OH) groups and those involved in hydrogen bonding. The Li + exchange decreases the extent of isolated hydroxyl groups, but the extent of H-bonding increases. This suggests that Li + is coordinated by the octahedral unit of the clay, through the O atoms (ions) of free Al-O-H groups. The ionic conductivity figures measured using AC-impedance analyzer is in agree with this bonding arrangement. It has been found that the intercalation of PEO in Li + -montmorillonite reverses the above process by the coordination of Li + ions with O atoms of PEO. The amount of free O-H then increases and the extent of hydrogen bonded O-H decreases.

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“…Измерение электропроводности монтмориллонитов как природных (выделенных из бентонитовых глин) [6,7], так и подвергнутых обогащению щелочными ионами по методикам ионного обмена [8][9][10] показали, что величина удельной проводимости этих твердых электролитов не позволяет отнести их к группе суперионных проводников. Тем не менее, функциональный потенциал этого материала, на наш взгляд, далеко не исчерпан.…”

Section: Introductionunclassified

Synthesis of a material with Na+ superionic conductivity based on Al2O3-pillared montmorillonite

Бутман¹,

Ovchinnikov²,

Nuralyev³

et al. 2013

LoM

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Предложена методика синтеза материалов с суперионной проводимостью по ионам щелочных металлов на основе слоисто-столбчатых алюмосиликатов. Измерена электропроводность Al 2 O 3-пилларного монтмориллонита, допированного ионами натрия, которая существенно выше, чем у исходного монтмориллонита и его обогащенной ионами Na+ формы, и достигает рекордных значений, обнаруженных ранее у бета-глиноземной керамики. Ключевые слова: монтмориллонит, пилларированный монтмориллонит, ионная проводимость, твердый электролит, суперионный проводник.

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A new family of fast ion conductor-montmorillonites

Cited by 20 publications

References 7 publications

Electrochemical measurements on clay minerals for possible sensor applications

Electrochemical measurements on clay minerals for possible sensor applications

Ionic Conductivity of poly(ethylene oxide) (PEO)-montmorillonite(MMT) Nanocomposites Prepared by Intercalation from Aqueous Medium

Synthesis of a material with Na+ superionic conductivity based on Al2O3-pillared montmorillonite

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