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Structure of liquid and glassy methanol confined in cylindrical pores

Denis Morineau·Regis Guegan·Yongde Xia·Christiane Alba-Simionesco
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Abstract

We present a neutron scattering analysis of the density and the static structure factor of confined methanol at various temperatures. Confinement is performed in the cylindrical pores of MCM-41 silicates with pore diameters D=24 angstrom and D=35 angstrom. A change of the thermal expansivity of confined methanol at low temperature is the signature of a glass transition, which occurs at higher temperature for the smallest pore. This is an evidence of a surface induced slowing down of the dynamics of the fluid. The structure factor presents a systematic evolution with the pore diameter, which has been analyzed in terms of excluded volume effects and fluid-matrix cross-correlation. Conversely to the case of Van der Waals fluids, it shows that stronger fluid-matrix correlations must be invoked most probably in relation with the H-bonding character of both methanol and silicate surface.

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Denis Morineau, Regis Guegan, Yongde Xia, Christiane Alba-Simionesco. 2004-03-12. Structure of liquid and glassy methanol confined in cylindrical pores. https://doi.org/10.1063/1.1762872

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