FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W1969210908> ?p ?o ?g. }

• W1969210908 endingPage "6438" @default.
• W1969210908 startingPage "6430" @default.
• W1969210908 abstract "Variable temperature 39K and 2H nuclear magnetic resonance (VT NMR) spectroscopy of K+-saturated hectorite, a prototypical smectite clay, provides new insight into the relationships between the structural and dynamical behavior of K+ and H2O in confinement and at surfaces. In d = 10 Å K-exchanged hectorite, interlayer K+ is rigidly held by the silicate rings, probably in 12-coordinate inner-sphere sites as in muscovite mica. In a 1/1.5 by weight hectorite/water paste, K+ occurs on interlayer and external surface sites that are indistinguishable by 39K NMR. The K+ environments experience changes in dynamical behavior over the temperature range from −50 to 60 °C that are directly related to H2O dynamics. 39K NMR of the paste sample shows dynamic line narrowing at low temperatures due to modulation of the electric field gradient (EFG) at frequencies of the order of the static line width (≈20 kHz) and two “melting”-type dynamic transitions near −10 °C, one for surface and one for confined K+. At and above 0 °C, K+ remains closely associated with the clay surfaces and experiences motion at frequencies greater than 200 kHz and less than 10 MHz, as revealed by 39K T1 relaxation behavior, nutation behavior, and the 39K quadrupolar product. These data are consistent with rapid exchange between inner- and outer-sphere K+ sites reported previously for K-montmorillonite based on molecular dynamics simulations. Deuterium NMR shows the presence of two unique H2O environments in the system: one structurally and dynamically consistent with bulk water between particles and one attributable to H2O confined in the interlayer. Confined H2O experiences anisotropic motion between −50 and 0 °C via fast rotation (>2 MHz) about a single axis oriented 127.5 ± 0.5° from the principal axis of the 2H EFG, potentially due to C2 rotation. This motion does not affect the 39K EFG significantly. Melting of free and confined H2O occurs between −10 and 0 °C and near 0 °C, respectively, similar to the melting behavior of K+ and likely reflecting the onset of molecular diffusion. At and above 10 °C, all H2O environments experience motion near or in excess of 300 kHz through at least three NMR-indistinguishable mechanisms, including Brownian motion of free water, exchange of free and confined H2O near particle edges, and diffusive motion of H2O that remains confined on the experimental time scale. The correlation between the rates of 2H and 39K motion and the observed melting transitions for both spin populations strongly suggest that 39K melting and dynamics above the melting transition are linked to an increase in the motional freedom of H2O." @default.
• W1969210908 created "2016-06-24" @default.
• W1969210908 creator A5054596487 @default.
• W1969210908 creator A5066434647 @default.
• W1969210908 creator A5089001432 @default.
• W1969210908 date "2008-03-28" @default.
• W1969210908 modified "2023-10-03" @default.
• W1969210908 title "H₂O and Cation Structure and Dynamics in Expandable Clays: ²H and ³⁹K NMR Investigations of Hectorite" @default.
• W1969210908 cites W1528929242 @default.
• W1969210908 cites W1965262661 @default.
• W1969210908 cites W1971338208 @default.
• W1969210908 cites W1971864741 @default.
• W1969210908 cites W1974711152 @default.
• W1969210908 cites W1980329105 @default.
• W1969210908 cites W1984436535 @default.
• W1969210908 cites W1985184053 @default.
• W1969210908 cites W1986813980 @default.
• W1969210908 cites W1992653965 @default.
• W1969210908 cites W1994468670 @default.
• W1969210908 cites W1997020364 @default.
• W1969210908 cites W1998880854 @default.
• W1969210908 cites W2000621608 @default.
• W1969210908 cites W2005374785 @default.
• W1969210908 cites W2011008315 @default.
• W1969210908 cites W2014964864 @default.
• W1969210908 cites W2015132445 @default.
• W1969210908 cites W2025878233 @default.
• W1969210908 cites W2026675615 @default.
• W1969210908 cites W2028102816 @default.
• W1969210908 cites W2029839663 @default.
• W1969210908 cites W2041949618 @default.
• W1969210908 cites W2048246800 @default.
• W1969210908 cites W2050407654 @default.
• W1969210908 cites W2051164538 @default.
• W1969210908 cites W2051543925 @default.
• W1969210908 cites W2053076401 @default.
• W1969210908 cites W2054055240 @default.
• W1969210908 cites W2055038512 @default.
• W1969210908 cites W2055042825 @default.
• W1969210908 cites W2055452803 @default.
• W1969210908 cites W2059836006 @default.
• W1969210908 cites W2060718485 @default.
• W1969210908 cites W2065446476 @default.
• W1969210908 cites W2075047161 @default.
• W1969210908 cites W2076841586 @default.
• W1969210908 cites W2085087109 @default.
• W1969210908 cites W2087881622 @default.
• W1969210908 cites W2092514196 @default.
• W1969210908 cites W2103212314 @default.
• W1969210908 cites W2108715087 @default.
• W1969210908 cites W2122316263 @default.
• W1969210908 cites W2127343304 @default.
• W1969210908 cites W2140430991 @default.
• W1969210908 cites W2147359847 @default.
• W1969210908 cites W2148316121 @default.
• W1969210908 cites W2149142713 @default.
• W1969210908 cites W2170809278 @default.
• W1969210908 cites W2274451004 @default.
• W1969210908 cites W4245677282 @default.
• W1969210908 doi "https://doi.org/10.1021/jp7119087" @default.
• W1969210908 hasPublicationYear "2008" @default.
• W1969210908 type Work @default.
• W1969210908 sameAs 1969210908 @default.
• W1969210908 citedByCount "38" @default.
• W1969210908 countsByYear W19692109082012 @default.
• W1969210908 countsByYear W19692109082013 @default.
• W1969210908 countsByYear W19692109082014 @default.
• W1969210908 countsByYear W19692109082015 @default.
• W1969210908 countsByYear W19692109082016 @default.
• W1969210908 countsByYear W19692109082017 @default.
• W1969210908 countsByYear W19692109082018 @default.
• W1969210908 countsByYear W19692109082019 @default.
• W1969210908 countsByYear W19692109082020 @default.
• W1969210908 countsByYear W19692109082021 @default.
• W1969210908 crossrefType "journal-article" @default.
• W1969210908 hasAuthorship W1969210908A5054596487 @default.
• W1969210908 hasAuthorship W1969210908A5066434647 @default.
• W1969210908 hasAuthorship W1969210908A5089001432 @default.
• W1969210908 hasConcept C113196181 @default.
• W1969210908 hasConcept C121332964 @default.
• W1969210908 hasConcept C1276947 @default.
• W1969210908 hasConcept C15744967 @default.
• W1969210908 hasConcept C159467904 @default.
• W1969210908 hasConcept C159985019 @default.
• W1969210908 hasConcept C178790620 @default.
• W1969210908 hasConcept C185592680 @default.
• W1969210908 hasConcept C192562407 @default.
• W1969210908 hasConcept C2776029896 @default.
• W1969210908 hasConcept C2776581184 @default.
• W1969210908 hasConcept C2777515222 @default.
• W1969210908 hasConcept C2779451542 @default.
• W1969210908 hasConcept C2779870107 @default.
• W1969210908 hasConcept C2781248345 @default.
• W1969210908 hasConcept C32891209 @default.
• W1969210908 hasConcept C46141821 @default.
• W1969210908 hasConcept C4839761 @default.
• W1969210908 hasConcept C62520636 @default.
• W1969210908 hasConcept C66974803 @default.

• next