rdf-syntax-grammar
mods:
  schema location: http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
  title info:
    title: Study of pure-silica zeolite nucleation and growth from solution
  name:
    name part: Li, Xiang.
    role:
      role term: creator
  name:
    name part: Shantz, Daniel F.
    role:
      role term: thesis advisor.
  type of resource: text
  genre: bibliography
  origin info:
    place:
      place term: txu
    date issued: 2011
    issuance: monographic
  language:
    language term: eng
  physical description:
    form: remote
    extent: 1 online resource.
  abstract: Zeolites are microporous crystalline materials, which are widely used in catalysis, adsorption, and ion-exchange processes. However, in most cases, the synthesis of novel zeolites as functional materials still relies on trial-and-error methods, which are time consuming and expensive. Therefore, the motivation for this thesis work is to understand the zeolite synthesis mechanismand further develop knowledge for manipulating zeolite properties and ultimately the rational design of porous materials. This work focused on formation of silicalite-1 (pure-silica ZSM-5) from basic aqueous solutions containing tetraorthosilicate (TEOS) as silica source, and tetrapropylammonium (TPA) cations as the organic structure-directing agent. The presence of silica precursor particles with size of 2-5 nm in these mixtures prior to and during hydrothermal treatments have been observed through dynamic light scattering (DLS), small-angle X-ray (SAXS) and transmission electron microscopy (TEM). However, to quantify composition and the molecular structure transformation of these silica precursor particles during zeolite synthesis is still a technical challenge. Another important yet unresolved question is how organocations interact with these nanoparticles and direct zeolite nuclei. Unlike many studies performed analyzing the inorganic phase (silica) present in synthesis mixtures, this study quantified the organocation-silica particle interaction and its ultimate effect on zeolite growth mainly through probing the behavior of the organocations. Pulsed-field gradient (PFG) NMR was used to capture the mobility change of organocations, and was complemented with scattering measurements (DLS, SAXS) on the silica nanoparticles. On the basis of the measurement results, the thermodynamic and kinetic properties of the organic-inorganic interaction were derived. Upon aging at room temperature, this interaction manifested as binding of TPA onto the silica particles due to electrostatic interactions, a…
  note: by Xiang Li.
  note: "Major Subject: Chemical Engineering"
  note: Title from author supplied metadata (automated record created 2011-11-01 09:04:20).
  note: Electronic resource.
  note: Doctor of Philosophy Texas A&M University 2011 http://hdl.handle.net/1969.1/ETD-TAMU-2011-08-9825
  note: Includes bibliographical references.
  note: Text (Dissertation)
  subject:
    topic: Major chemical engineering
  subject:
    topic: PFG NMR
  subject:
    topic: nucleation and crystallization
  subject:
    topic: kinetics
  subject:
    topic: zeolites
  identifier: http://hdl.handle.net/1969.1/ETD-TAMU-2011-08-9825
  record info:
    record content source: TXA
    record creation date: 111115
    record change date: 20151202144228.0
    record identifier: in00002727657