TY - JOUR

T1 - Quantifying adsorption-induced deformation of nanoporous materials on different length scales

AU - Morak, Roland

AU - Braxmeier, Stephan

AU - Ludescher, Lukas

AU - Balzer, Christian

AU - Putz, Florian

AU - Busch, Sebastian

AU - Hüsing, Nicola

AU - Reichenauer, Gudrun

AU - Paris, Oskar

PY - 2017

Y1 - 2017

N2 - A new in situ setup combining small-angle neutron scattering (SANS) and dilatometry was used to measure water-adsorption-induced deformation of a monolithic silica sample with hierarchical porosity. The sample exhibits a disordered framework consisting of macropores and struts containing two-dimensional hexagonally ordered cylindrical mesopores. The use of an H2O/D2O water mixture with zero scattering length density as an adsorptive allows a quantitative determination of the pore lattice strain from the shift of the corresponding diffraction peak. This radial strut deformation is compared with the simultaneously measured macroscopic length change of the sample with dilatometry, and differences between the two quantities are discussed on the basis of the deformation mechanisms effective at the different length scales. It is demonstrated that the SANS data also provide a facile way to quantitatively determine the adsorption isotherm of the material by evaluating the incoherent scattering contribution of H2O at large scattering vectors.

AB - A new in situ setup combining small-angle neutron scattering (SANS) and dilatometry was used to measure water-adsorption-induced deformation of a monolithic silica sample with hierarchical porosity. The sample exhibits a disordered framework consisting of macropores and struts containing two-dimensional hexagonally ordered cylindrical mesopores. The use of an H2O/D2O water mixture with zero scattering length density as an adsorptive allows a quantitative determination of the pore lattice strain from the shift of the corresponding diffraction peak. This radial strut deformation is compared with the simultaneously measured macroscopic length change of the sample with dilatometry, and differences between the two quantities are discussed on the basis of the deformation mechanisms effective at the different length scales. It is demonstrated that the SANS data also provide a facile way to quantitatively determine the adsorption isotherm of the material by evaluating the incoherent scattering contribution of H2O at large scattering vectors.

KW - mesoporous materials; small-angle neutron scattering; dilatometry; adsorption-induced deformation; adsorption isotherms.

U2 - 10.1107/S1600576717012274

DO - 10.1107/S1600576717012274

M3 - Article

VL - 50

SP - 1404

EP - 1410

JO - Journal of applied crystallography

JF - Journal of applied crystallography

SN - 1600-5767

M1 - 5

ER -