The combination of physisorption experiments with simultaneous in situ small-angle X-ray and neutron scattering (SAXS/SANS) was used to elucidate the porosity in mesoporous silica with a trimodal pore structure. The material ("KLE-IL") contains spherical mesopores of 14 nm in diameter, worm-like mesopores (2-3 nm), and micropores, templated by a block copolymer and an ionic liquid surfactant, while the micropores originate from the hydrophilic block of the block copolymer. The main objective of the study was the quantification of the microporosity and the small mesopores and to find out if they are indeed located between the larger, spherical mesopores. Our in situ SAXS/SANS experiments took advantage of contrast matching of nitrogen (SANS, T = 77 K) and dibromomethane (SAXS, T = 290 K). By using the latter gas with a slightly larger kinetic diameter, it was possible to judge the accessibility of the pores under ambient conditions. The in situ experiments were supported by high-precision ex situ physisorption. Using suitable approaches for the SAXS/SANS analysis, it was possible to separate the content of the micropores and small mesopores.

The solution structure and the aggregation behavior of stiff polymer-peptide nanofibers, selfassembled from well-defined poly(ethylene oxide)-peptide conjugates are described. Aqueous solutions at different concentrations of core-shell nanofibers were investigated by cryo-fixation transmission electron microscopy (cryoTEM) and small-angle neutron scattering (SANS). Both methods show the presence of stiff, extended nanofibers in dilute solution, providing nanodimensions for the fiber cross section, which are in good agreement with previously shown investigations on dried and deposited fibers. Moreover the previously suggested coreshell character of the fiber cross section could be verified by SANS density profiles. In concentrated solutions exceeding 2 mg/mL, the nanofibers tended to further organize into nematic "bundles". Polarized optical microscopy (POM) indeed shows birefringence of the solutions and typical Schlieren textures in shear oriented films, consistent with high aspect ratio nanofibers. The results of this investigation are discussed in the context of the Flory theory of rigid rods.