Distribution of functional groups in periodic mesoporous organosilica materials studied by small-angle neutron scattering with in situ adsorption of nitrogen.

ABSTRACT: Periodic mesoporous materials of the type (R'O)(3)Si-R-Si(OR')(3) with benzene as an organic bridge and a crystal-like periodicity within the pore walls were functionalized with SO(3)H or SO(3) (-) groups and investigated by small-angle neutron scattering (SANS) with in situ nitrogen adsorption at 77 K. If N(2) is adsorbed in the pores the SANS measurements show a complete matching of all of the diffraction signals that are caused by the long-range ordering of the mesopores in the benzene-PMO, due to the fact that the benzene-PMO walls possess a neutron scattering length density (SLD) similar to that of nitrogen in the condensed state. However, signals at higher q-values (>1 1/Å) are not affected with respect to their SANS intensity, even after complete pore filling, confirming the assumpt

SUBMITTER: Sharifi M 

PROVIDER: S-EPMC3388367 | biostudies-literature | 2012

REPOSITORIES: biostudies-literature