Browsing by Author "Wang, TH"

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    Interactions involving strontium and various organic acids on the surface of bentonite (MX-80)
    (Springer, 2015-04-01) Wang, TH; Payne, TE; Harrison, JJ; Teng, SP
    The adsorption of strontium (Sr) by bentonite in the presence of various dicarboxylic and aromatic acids was investigated. Strontium uptake was strongly influenced by ionic strength, but not by the presence of the organic acids. However, Sr significantly affected the binding of the organic acids. X-ray diffraction (XRD) results suggested that the interlayer spacing of MX-80 bentonite was affected by the presence of Sr, particularly when organic acids were also present. Cation exchange is the major Sr uptake mechanism, and competition with divalent ions should be considered. Thermodynamic modelling and XRD results suggested that surface precipitation of Sr occurs at high pH values. © 2015, Springer.
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    Ultrasensitive barocaloric material for room-temperature solid-state refrigeration
    (Springer Nature, 2022-04-28) Ren, QY; Qi, J; Yu, DH; Zhang, Z; Song, R; Song, WL; Yuan, B; Wang, TH; Ren, WJ; Zhang, ZD; Tong, X; Li, B
    One of the greatest obstacles to the real application of solid-state refrigeration is the huge driving fields. Here, we report a giant barocaloric effect in inorganic NH4I with reversible entropy changes of ΔSmax P0!P ∼71 J K−1 kg−1 around room temperature, associated with a structural phase transition. The phase transition temperature, Tt, varies dramatically with pressure at a rate of dTt/dP ∼0.79 K MPa−1, which leads to a very small saturation driving pressure of ΔP ∼40 MPa, an extremely large barocaloric strength of ΔSmax P0!P=ΔP∼1.78 J K−1 kg−1 MPa−1, as well as a broad temperature span of ∼41 K under 80 MPa. Comprehensive characterizations of the crystal structures and atomic dynamics by neutron scattering reveal that a strong reorientation-vibration coupling is responsible for the large pressure sensitivity of Tt. This work is expected to advance the practical application of barocaloric refrigeration. © The Author(s) 2022. This article is licensed under a Creative Commons Attribution 4.0 International License.