Preparation of a Completely Oriented Molecular Sieve Membrane

Abstract

Growth of oriented seed crystals on a substrate led to a completely oriented and continuous membrane of LTA-type zeolite. The seed crystals of cubic morphology were dip-coated onto a tilted substrate (see schematic diagram) with the zeolite channels normal to the surface. The substrate was hydrothermally treated in a reaction mixture containing the organic ligand 2,2-bis(hydroxymethyl)-2,2',2"-nitrilotriethanol, which lowers the degree of supersaturation of [Al(OH)(4)](-) ions and preferentially facilitates the intergrowth of the seed crystals.

Organization of Zeolite Microcrystals for Production of Functional Materials

“…The adsorption methods were slow evaporation, 30 dip coating, 27,32 and convective assembly (vertical deposition). 31 Polystyrene can also be applied for stronger adhesion.…”

Crystallization and crystal morphology of silicalite-1 prepared from silica gel using different amines as a base

“…The pH value of this suspension was adjusted to about 10 using 20% TPAOH aqueous solution. This suspension was spread onto a glass substrate by the dip-coating method, which we reported previously [28].…”

Oriented growth and assembly of zeolite crystals on substrates

“…Tsapatsis et al [52] repeated dip-coating and subsequent drying procedure up to 5 times to fabricate fully covered silicalite-1 (~100 nm) seed layer. Besides, Takahashi et al [53] conducted dip-coating by immersing the substrate at a tilt angle of 45° to prepare the fully covered and (h00)-oriented LTA-type zeolite seed layer. Bein et al [54] adopted the spin-coating technique to assemble b-oriented ZSM-5 crystals (15 and 30 nm) on various substrates such as silicon wafer, Au, and LiNbO 3 .…”