Determination of Pore Size in Mesoporous Thin Films from the Annihilation Lifetime of Positronium

Dull, T. L.; Frieze, W. E.; Gidley, David W.; Sun, Jianing; Yee, A. F.

doi:10.1021/jp004182v

Cited by 270 publications

(268 citation statements)

References 27 publications

(70 reference statements)

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“…3) were useful for checking possibility to apply contemporary theoretical models, connecting EFV size and positronium lifetimes, to our experimental results. We mean here extended Tao-Eldrup (ETE) model suggested by Goworek et al [16,17] and so-called "classical regime", considering Ps atom as a classical particle in a large hole [18,19]. Analysis of our TD-data shows that the classical free path concept Distribution of the free volume holes sizes in polymeric sorbent LPS200X found from the sorption experiments.…”

Section: Concentration and Size Distribution Of Elementary Free Volumessupporting

confidence: 50%

Some Aspects of Free Volume Studies in Molecular Substances Using Positron Annihilation Experiments

et al. 2005

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Section: Concentration and Size Distribution Of Elementary Free Volumessupporting

confidence: 50%

Some Aspects of Free Volume Studies in Molecular Substances Using Positron Annihilation Experiments

et al. 2005

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“…The average pore diameter for τ 3 was calculated using the Tao-Eldrup model assuming infinitely long cylindrical pore shape [30,31]. The pore sizes for the long lifetimes (τ 4 and τ 5 ) were calculated using the rectangular Tao-Eldrup (RTE) model based on an infinitely long channel [32].…”

Section: Characterisationmentioning

confidence: 99%

Desalination of seawater ion complexes by MFI-type zeolite membranes: Temperature and long term stability

Zhu

Zhou

Milne

et al. 2014

Journal of Membrane Science

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Desalination of seawater ion complexes by MFI-type zeolite membranes: temperature and long term stability, Journal of Membrane Science, http://dx.doi.org/10.1016/j.memsci. 2013.10.071 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting galley proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. 2 high rejection (>93%) for all major seawater ions including Na + (except for K + , 83%) at an applied pressure of 700 kPa and room temperature (22 °C), but showed a continuous decrease in ion rejection when increasing the temperature from 22 °C and 90 °C. Permeation flux of the zeolite membrane significantly increased with increasing in temperature. Upon closer observation of the major cations, size selective diffusion in the zeolite membrane was observed over the temperatures tested. Larger ions Ca 2+ and Mg 2+ were less responsive to temperature than smaller ions Na + and K + . No changes in membrane structure were observed by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) after 180 days seawater exposure. However, energy-dispersive X-ray spectroscopy (EDS) mapping on the surface of the membrane revealed a small quantity of tightly bound divalent cations present in the structure, which appear to have penetrated the zeolite, accelerated by temperature. They were suspected to have altered the permstructure, explaining why original high rejections at room temperature were not reversed after heat exposure. The work has shown that zeolite membranes can desalinate seawater, but other unusual effects such as ion selective diffusion as a function of temperature indicate a unique property for desalination membrane materials.

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“…were calculated using the rectangular Tao-Eldrup (RTE) model based on an infinitely long channel [29].…”

Section: Palsmentioning

confidence: 99%

Designing hierarchical porous features of ZSM-5 zeolites via Si/Al ratio and their dynamic behavior in seawater ion complexes

Zhu

Doherty

et al. 2013

Microporous and Mesoporous Materials

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MFI-type zeolites were characterized using powder x-ray diffraction (XRD), and positron annihilation lifetime spectroscopy (PALS) to uncover the hierarchical porous * Corresponding author. Tel: +61 3 9919 7682; fax: +61 3 9919 7696. Email: mikel.duke@vu.edu.au (M. Duke). overall release of ions, principally Na + and K + , which were liberated mainly from the zeolite channels, yet these materials adsorbed Ca 2+ in the microporous grain boundaries and Mg 2+ in the mesoporous grain boundaries. Si/Al = 100 appeared to be a unique ratio, allowing the material to possess the same Na + adsorption features (and hydrophilicity) of high alumina materials, but ion interactions resembling high silica materials. MFI-type zeolite is therefore shown to be highly configurable using Si/Al ratio for a wide variety of applications in the presence of ions.

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Determination of Pore Size in Mesoporous Thin Films from the Annihilation Lifetime of Positronium

Cited by 270 publications

References 27 publications

Some Aspects of Free Volume Studies in Molecular Substances Using Positron Annihilation Experiments

Some Aspects of Free Volume Studies in Molecular Substances Using Positron Annihilation Experiments

Desalination of seawater ion complexes by MFI-type zeolite membranes: Temperature and long term stability

Designing hierarchical porous features of ZSM-5 zeolites via Si/Al ratio and their dynamic behavior in seawater ion complexes

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