The ability to examine conducting filler particles in an insulating polymer matrix by scanning electron microscopy (SEM) was investigated. The detection of selected secondary electrons is necessary to resolve sub-micron scale filler particles, but not every SEM detector seems to be able to monitor the small changes introduced by the conducting filler particles. The influence of SEM parameters and the challenge of image interpretation in view of the apparent lack of appropriate information in literature are discussed. In accordance with other experiments on light element samples, all monitored electrons seem to be emitted within approximately 50 nm of the sample depth and no information is accessible from deeper regions even by increasing the acceleration voltage.

a b s t r a c tQuaternary ammonium compounds are known to have extremely high affinity to carbon dioxide. Two new highly hydrophilic compounds containing one or two quaternary ammonium moieties attached to the reactive trimethoxy silane were synthesized and studied for physico-chemical and gas transport properties in the dry and wet environments. Both compounds in the form of blends with PEBAX ® MH 1657 showed high CO 2 solubility coefficients and high CO 2 /N 2 (up to 1500) and CO 2 /H 2 (up to 1350) solubility selectivity. The dry gas measurements revealed the presence of specific interaction with CO 2 resulting in strong binding of the gas molecule to the polymer active center resulting in increased solubility and decreased diffusion coefficients. At low temperatures CO 2 was irreversibly sorbed in the quaternary ammonium compound and was released only at temperatures higher than 60 • C. For the sample modified by co-hydrolysis with TEOS the temperature of 60 • C was found to be an additional transition point giving for H 2 , N 2 , O 2 and CO 2 break on the solubility coefficient Arrhenius plots. Measurements carried out with humid feed revealed up to 35-fold increase of gas permeability without CO 2 /N 2 and CO 2 /H 2 ideal selectivity loss compared to the dry gas measurements.

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