Hydration enthalpies of inorganic porous materials with different structures

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Author(s)

    • SUZUKI Masaya
    • National Industrial research institute of Nagoya, AIST, MITI
    • MAEDA Masaki
    • National Industrial research institute of Nagoya, AIST, MITI
    • TOMURA Shinji
    • National Industrial research institute of Nagoya, AIST, MITI
    • MIZOTA Tadato
    • Department of Advanced Materials Science and Engineering, Faculty of Engineering, Yamaguchi University

Abstract

The hydration enthalpies of three inorganic porous materials (sepiolite, MCM41 and synthesized allophane) were measured by means of the adiabatic vapor absorption calorimeter. The average hydration enthalpy (−Δ<I>H</I><SUB>h</SUB>) were in the order, allophane (−57kJ/mol)<sepiolite (−54kJ/mol)<MCM41 (−49kJ/mol) when the samples were hydrated for 10 minutes in the calorimeter, after dehydration in vacuum at 100°C. Samples with smaller pore radius give the larger absolute values of the hydration enthalpy (−Δ<I>H</I><SUB>h</SUB>). The −Δ<I>H</I><SUB>h</SUB> values of sepiolite increased with dehydration temperature and decreased with hydration duration, whereas that of MCM41 remained almost constant regardless of dehydration temperature and hydration duration. The hydration rates for these samples were large in the early stage, but quickly lost the rate. The hydration state of the porous materials with large voids is concluded being similar to that of free water.

Journal

  • Mineralogical Journal

    Mineralogical Journal 22(1), 1-10, 2000-01-01

    Japan Association of Mineralogical Sciences

References:  14

Cited by:  5

Codes

  • NII Article ID (NAID)
    10008773619
  • NII NACSIS-CAT ID (NCID)
    AA00739590
  • Text Lang
    ENG
  • Article Type
    Journal Article
  • ISSN
    05442540
  • Data Source
    CJP  CJPref  J-STAGE 
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