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We show that the morphology of polymer-based solar cells substantially changes after annealing using small angle neutron scattering. Phenyl-C61-butyric acid methyl ester (PCBM) is found reasonably well dispersed within the poly(3-hexylthiophene) (P3HT) rich phase after initial processing (spin coating). However, the PCBM structure coarsens after annealing, clearly evidenced by the increase in scattering intensity at a small wave vector. The change in morphology at the nanoscale is related to improved device performance and the simultaneous, contradictory, increase in photoluminescence.

17The pore size distribution and architecture in gas shale were studied using a combination of 18 small-angle neutron scattering (SANS), mercury injection capillary pressure (MICP), and helium 19 ion microscopy (HIM). SANS analysis shows that the pore size population is not a power-law 20 distribution across many length scales, typical of sedimentary rocks, but contains an anomalous 21 population of pores on-the-order ~2 nm, housed primarily in the organic matter. A model is 22presented showing how a "foamy porosity" with such a characteristic size is a direct result of 23 diagenetic evolution of kerogen. Cross-linking of the kerogen combined with phase separation 24 of gas/oil, leads to arrested coarsening with a length scale set by cross-length density. These 25 pore populations determined by the scattering model are directly supported by HIM images. 26Pore connectivity determined through pore size-to-pore-throat analysis, suggests that inter pore 27 connections are also distinct from typical sedimentary rocks. The pore/throat ratio, unlike the 28 simple ratios predicted from sphere packing and found for clastic rocks, is nearly constant over 29 all pore sizes. Kerogen diagenesis is a recognized source of excess internal pressure. When this 30 pressure causes failure of the material surrounding the kerogen to create escape pathways for the 31 phase-separated fluid, it is likely that escape pathways will connect intergranular porosity via 32 microfractures, producing the relatively narrow aperture size distribution. 33 34

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