Microstructural characterization of an oriented silicalite film

The crystal orientation of a submicron silicalite membrane is examined using standard x-ray diffraction and pole-figure analyses. Results indicate that the crystals in the molecular sieving layer are preferentially oriented with both straight and sinusoidal channel networks of the zeolite parallel to the membrane surface. This requires that transport across the membrane proceed down the c-axis of the crystals which can occur by jumping between the two channel networks. EDAX data confirms that the molecular sieving layer is the pure silica zeolite silicalite.