Crosslinked poly(ethylene glycol diacrylate) (PEGda) oligomers differing in molecular weight, and their nanocomposites prepared with up to 10 wt.‐% methacrylate‐functionalized fumed silica (FS) or an organically‐modified nanoclay, have been examined as amorphous CO2‐selective membranes. These novel materials have been characterized by dynamic rheology before and after crosslinking to ascertain the effect of incorporated FS on mechanical properties. The permeabilities of CO2, H2, N2, and O2 have been measured as functions of PEGda molecular weight, nanofiller content and temperature. In all cases, CO2 displays relatively high permeability, coupled with high CO2 selectivity, due to the specific interaction between quadrupolar CO2 and the ether linkages along the PEG backbone, and the accompanying enhancement in CO2 solubility. Variable‐temperature permeation exhibits Arrhenius behavior, and the activation energy for CO2 permeation is found to be i) markedly lower than that of any of the other gases examined, and ii) independent of both PEGda molecular weight and nanofiller content.

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Birefringence, arising from locally preferred orientation of molecules or functional groups in polymeric and related materials has been observed in a near-field scanning optical microscope (NSOM) at suboptical spatial resolution. Our observations were successfully correlated to existing structural models of the samples, demonstrating the utility of birefringence observations in NSOM. We present data acquired from thin sections of a partially ordered polymer fiber (Kevlar) and a polymer dispersed small-moleculeliquid-crystal composite.

SUMMARY Incorporation of liquid crystalline polymers (LCPs) into commodity polymers remains a challenge in the design of high-performance, low-cost polymeric blends. Blends of a thermoplastic polymer and a nematic LCP are produced here by mechanical alloying. Functionality sensitive X-ray microscopy reveals LCP dispersions as small as 100 nm in diameter. Intimate mixing remains upon subsequent melt processing, indicating that mechanical alloying is suited for applications such as recycling.