Real Time 3D Observations of Portland Cement Carbonation at CO Storage Conditions.

Depleted oil reservoirs are considered a viable solution to the global challenge of CO storage. A key concern is whether the wells can be suitably sealed with cement to hinder the escape of CO. Under reservoir conditions, CO is in its supercritical state, and the high pressures and temperatures involved make real-time microscopic observations of cement degradation experimentally challenging.

Nonionic Fluorinated Surfactant Removal from Mesoporous Film Using sc-CO.

Surfactant templated silica thin films were self-assembled on solid substrates by dip-coating using a partially fluorinated surfactant R(EO) as the liquid crystal template. The aim was 2-fold: first we checked which composition in the phase diagram was corresponding to a 2D rectangular highly ordered crystalline phase and second we exposed the films to sc-CO to foster the removal of the surfactant. The films were characterized by in situ X-ray reflectivity (XRR) and grazing incidence small angle X-ray scattering (GISAXS) under CO pressure from 0 to 100 bar at 34 °C.

X-Ray Nanoscopy of a Bulk Heterojunction.

Optimizing the morphology of bulk heterojunctions is known to significantly improve the photovoltaic performance of organic solar cells, but available quantitative imaging techniques are few and have severe limitations. We demonstrate X-ray ptychographic coherent diffractive imaging applied to all-organic blends. Specifically, the phase-separated morphology in bulk heterojunction photoactive layers for organic solar cells, prepared from a 50:50 blend of poly(3-hexylthiophene) (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM) and thermally treated for different annealing times is imaged to high resolution.

Stability of Polymer Ultrathin Films (<7 nm) Made by a Top-Down Approach.

In polymer physics, the dewetting of spin-coated polystyrene ultrathin films on silicon remains mysterious. By adopting a simple top-down method based on good solvent rinsing, we are able to prepare flat polystyrene films with a controlled thickness ranging from 1.3 to 7.