Fabrication of Al-beta/silicalite-1 hydrophilic-hydrophobic zeolite membranes.

Hydrophobic-hydrophilic composite membranes containing silicalite-1 and Al-beta zeolites are prepared on the outer surface of the porous alpha-alumina tube for the first time. The hydrophilic layer with aluminum serves as an active catalytic domain, whereas the hydrophobic layer containing silicalite-1 with medium pore-size is expected to assist in separating the reaction products based on their hydrophobicity as well as shape-selectivity. The continuous defect-free composite membranes are fabricated by two-step synthesis approach by initial deposition of Al-beta crystals on the outer surface of porous alumina tube followed by coating of silicalite-1 crystals over the Al-beta layer in the second step under hydrothermal conditions.

Zeolites as new chromatographic carriers for proteins--easy recovery of proteins adsorbed on zeolites by polyethylene glycol.

Zeolites are able to adsorb proteins on their surface and might be suitable as a new type of chromatographic carrier material for proteins and for their conjugates (Matsui et al., Chem. Eur.

A Novel Layered Silicate with a Helical Morphology.

Helices composed of stacked layers are present in the novel silicate obtained from a silica sol and NaOH by hydrothermal synthesis in the presence of tetramethylammonium (TMA) hydroxide and 1,4-dioxane. The helical morphology is evident in scanning electron micrographs (see picture). The TMA and sodium ions of the silicate are readily replaced by protons, and on heating to 200°C a reversible phase transition occurs in which water molecules are lost from between the layers.