TY - JOUR

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

AU - Morak, Roland

AU - Braxmeier, Stephan

AU - Ludescher, Lukas

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) anddilatometry was used to measure water-adsorption-induced deformation of amonolithic silica sample with hierarchical porosity. The sample exhibits adisordered framework consisting of macropores and struts containing twodimensionalhexagonally ordered cylindrical mesopores. The use of an H2O/D2O water mixture with zero scattering length density as an adsorptive allows aquantitative determination of the pore lattice strain from the shift of thecorresponding diffraction peak. This radial strut deformation is compared withthe simultaneously measured macroscopic length change of the sample withdilatometry, and differences between the two quantities are discussed on thebasis of the deformation mechanisms effective at the different length scales. It isdemonstrated that the SANS data also provide a facile way to quantitativelydetermine the adsorption isotherm of the material by evaluating the incoherentscattering contribution of H2O at large scattering vectors.

AB - A new in situ setup combining small-angle neutron scattering (SANS) anddilatometry was used to measure water-adsorption-induced deformation of amonolithic silica sample with hierarchical porosity. The sample exhibits adisordered framework consisting of macropores and struts containing twodimensionalhexagonally ordered cylindrical mesopores. The use of an H2O/D2O water mixture with zero scattering length density as an adsorptive allows aquantitative determination of the pore lattice strain from the shift of thecorresponding diffraction peak. This radial strut deformation is compared withthe simultaneously measured macroscopic length change of the sample withdilatometry, and differences between the two quantities are discussed on thebasis of the deformation mechanisms effective at the different length scales. It isdemonstrated that the SANS data also provide a facile way to quantitativelydetermine the adsorption isotherm of the material by evaluating the incoherentscattering 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 - 50.2017

SP - 1404

EP - 1410

JO - Journal of applied crystallography

JF - Journal of applied crystallography

SN - 1600-5767

M1 - 5

ER -