Contactez-nous! +33 (0)2 31 45 28 21
lcs@ensicaen.fr
  • Français
Laboratoire Catalyse et SpectrochimieLaboratoire Catalyse et SpectrochimieLaboratoire Catalyse et SpectrochimieLaboratoire Catalyse et Spectrochimie
  • Who are we?
  • Research at LCS
    • Publications
    • EDRF Projects
    • ANR projects
    • Research at LCS
      • Spectrocat group
      • Zeolithes group
    • News
    • Lab activities and organization
    • Education
    • The doctoral and postdocs blog
    • History
  • Technical platforms
    • Catalytic Tests & Chemisorption Platform
    • VISIO platform
    • Solid State NMR platform
      (NMR center of Caen-Normandy)
    • Synthesis & Characterization Platform
  • Industrial partnership
  • Contact us!
    • Work at the lab
    • Contact us!
    • Laboratory staffs
    • LCSValoris serving companies
Next Previous

Silicate ionic liquid synthesis of zeolite merlinoite: Crystal size control from crystalline nanoaggregates to micron-sized single-crystals

22 July 2014

Mohamed Haouas, Louwanda Lakiss, Charlotte Martineau, Jaafar El Fallah, Valentin Valtchev, Francis Taulelle

Microporous and Mesoporous Materials

DOI: 10.1016/j.micromeso.2014.07.011

Highlights1-s2.0-S1387181114003692-fx1
•Hydrated silicate ionic liquid is obtained by a two-steps procedure from TEOS.
•Coacervation was observed in highly alkaline solution.
•Phase separation by decantation allows extraction of silicate phase.
•Synthesis of purely mineral merlinoite was achieved from clear liquid.
•Large single-crystals are formed in low Al and water content precursors.

Abstract
A new procedure for zeolite synthesis based on a silicate ionic liquid is reported. The method consists of a two-step precursor preparation. In the first step, a liquid silicate is prepared by hydrolyzing tetraethylorthosilicate (TEOS) with KOH-H2O mixture, which induces coacervation resolved into full phase demixing and subsequent separation from a water-ethanol phase by simple decantation. In the second step, an appropriate amount of an alkaline aluminate is mixed with the first liquid silicate, avoiding therefore precipitation. To the best of our knowledge, this represents the first example of homogeneous liquid synthesis, and not a clear sol or a gel, of an Al-rich zeolite, free of organic template. The approach is exemplified by the synthesis of merlinoite with potassium hydroxide as mineral base and could be extended to other zeolitic systems by varying the chemical composition and the nature of the alkali cation. The synthesis yield depends on the Al content and the crystalline products showed a very large range of particle sizes varying from nanometer scale to about a hundred microns when increasing the Al concentration. Crystallization proceeds most likely through nucleation from a liquid where nucleation and growth directly affects the ultimate crystal size and morphology.

Keywords
Colloid; Silicate Nanoparticles; Silicate Ionic Liquid; Coacervation; NMR; Zeolite Synthesis; Merlinoite

Copyright 2021 - Laboratoire Catalyse & Spectrochimie - Directeur de publication : Guillaume CLET | Creative Commons 4.0 International
  • Français
Laboratoire Catalyse et Spectrochimie
Login

Lost your password?

Reset Password

Log in