% IMPORTANT: The following is UTF-8 encoded.  This means that in the presence
% of non-ASCII characters, it will not work with BibTeX 0.99 or older.
% Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or
% “biber”.

@PHDTHESIS{Hoffmann:141527,
      author       = {Hoffmann, Jan},
      title        = {{I}nnovative {B}eschichtungs- und
                      {C}harakterisierungsmethoden für die nasschemische
                      {H}erstellung von asymmetrischen {G}astrennmembranen auf
                      {B}asis von {S}i{O}$_{2}$},
      volume       = {195},
      school       = {Universität Bochum},
      type         = {Dissertation},
      address      = {Jülich},
      publisher    = {Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag},
      reportid     = {FZJ-2013-06695},
      isbn         = {978-3-89336-917-1},
      series       = {Schriften des Forschungszentrums Jülich Reihe Energie $\&$
                      Umwelt / Energy $\&$ Environment},
      pages        = {V, 152 S.},
      year         = {2013},
      note         = {Dissertation, Universität Bochum, 2013},
      abstract     = {Introducing membrane separations in industrial processes
                      has the potential to increase the energy efficiency and
                      reduce the environmental impact of their corresponding
                      processes. One prominent example is the use of membranes for
                      CO$_{2}$ capture in fossil fuel power plants. Ceramic
                      membranes are promising candidates for this application due
                      to their high resistance to significant thermal and
                      mechanical strain. It is well studied and known that
                      SiO$_{2}$-based membranes show the desired gas separation
                      properties for CO$_{2}$. According to the current state of
                      the art, these gas separation properties are based on a
                      molecular sieving process that wasdemonstrated
                      experimentally on a laboratory scale. The lab scale
                      membranes yielded low reproducibility on a small tested
                      area. For potential industrial use, SiO$_{2}$-based membrane
                      production must be readily reproducible and scalable to
                      larger areas. The present work deals with the study of
                      production and characterization methods to increase the
                      reproducibility of graded SiO$_{2}$ membranes. A model
                      system is introduced that utilizes a standardized membrane
                      structure consisting of a $\alpha$-Al$_{2}$O$_{3}$
                      substrate, a $\gamma$-Al$_{2}$O$_{3}$ interlayer and a
                      SiO$_{2}$-function layer. A characterization routine is
                      developed to evaluate this model system and specific
                      variations of the structure (e.g. the use of alternative
                      substrates). With that routine, it is possible to
                      systematically analyze the individual components of the
                      structure and obtain influencing factors on reproducibility.
                      The characterization of different sets of samples shows that
                      defects in the functional layer contribute largely to
                      reduced reproducibility. A method is developed for the
                      targeted analysis of these defects, which allows for a
                      space-resolved characterization in various optical analysis
                      techniques to be performed. Space-resolved characterization
                      shows that both inhomogeneity in the substrate and
                      contamination with foreign particles causes defects that
                      lower the reproducibility of the resulting SiO$_{2}$ layers.
                      In addition, a novel process for the preparation of
                      SiO$_{2}$ functional layers for gas separation using ink jet
                      printing is introduced. This method is scalable to large
                      areas and offers the advantage of a digital controller. It
                      is shown that by using an appropriate parameter set,
                      SiO$_{2}$-based homogeneous functional layers can be printed
                      on a $\alpha$-Al$_{2}$O$_{3}$ substrate and a
                      $\gamma$-Al$_{2}$O$_{3}$-interlayer. The heat treatment is
                      done by a rapid thermal heating process of the layers, which
                      significantly shortens the duration of the manufacturing
                      process. Characterization of these layers shows that
                      H$_{2}$/CO$_{2}$ selectivity can be clearly achieved up to
                      50. The results provide a solid starting point for future
                      improvements on the reproducible production of ceramic
                      layers for gas separation. In particular, the method of
                      space-resolved characterization may lead to better
                      evaluation of the factors that influence reproducibility.
                      From an industrial perspective, the developed ink-jet
                      printing model offers the advantages of efficiency,
                      scalability, and reproducible production of SiO$_{2}$
                      functional layers.},
      keywords     = {Dissertation (GND)},
      cin          = {IEK-1},
      cid          = {I:(DE-Juel1)IEK-1-20101013},
      pnm          = {123 - Fuel Cells (POF2-123)},
      pid          = {G:(DE-HGF)POF2-123},
      typ          = {PUB:(DE-HGF)3 / PUB:(DE-HGF)11},
      url          = {https://juser.fz-juelich.de/record/141527},
}