title: Fabrication of b-Oriented MFI Zeolite Films under Neutral Conditions without the Use of Hydrogen Fluoride.
abstract: The fabrication of MFI zeolite films with particular b-axis orientation is especially fascinating. Unlike the conventional alkaline or hydrofluoric acid (HF) assisted neutral synthesis route, here we develop a novel neutral synthesis solution system of TPABr/fumed silica/H2 O without the use of HF and successfully synthesize highly b-oriented MFI zeolite films on glass-plate substrates by secondary growth. The localized weak alkaline environment created by the dissolved Na2 O species from the substrate is identified as the key factor for the depolymerization of fumed silica and subsequently the in-plane growth of zeolite seed layers. Continuous b-oriented MFI films can also be synthesized on other substrates in the presence of a glass plate or a trace amount of NaOH, which making our neutral synthesis route promising for the direct synthesis of MFI zeolite films and membranes on various substrates.
authors.affiliation: College of Chemical and Biological Engineering and MOE Engineering Research Center of Membrane and Water Treatment Technology, Zhejiang University, Hangzhou 310027 (PR China).
authors.forename: Yong
authors.initials: Y
authors.lastname: Peng
authors.forename: Xiaofei
authors.initials: X
authors.lastname: Lu
authors.forename: Zhengbao
authors.initials: Z
authors.lastname: Wang
authors.forename: Yushan
authors.initials: Y
authors.lastname: Yan
keywords: MFI; hydrothermal synthesis; oriented film; thin films; zeolites