Characterization of worm-like micro- and mesoporous silicas by small-angle scattering and high-resolution adsorption porosimetry

Mesoporous silica with worm-like pores of 9-10 nm in size were studied by small-angle neutron scattering (SANS) and high-resolution porosimetry, using nitrogen at 77 K and argon at 87 K. The pore sizes determined from SANS are in excellent agreement with those obtained from a recently developed non-local density functional theory (NLDFT) approach. Furthermore, the additional micropores in the mesopore walls could be quantified by SANS and physisorption, and again good agreement between both methods was observed. Our results clearly demonstrate that the NLDFT approach allows an accurate determination of the pore size distribution of materials which contain both narrow micropores and mesopores larger than 10 nm.