Atomic Layer Deposition-Modified Ordered Mesoporous Silica Membranes

Authors

  • David E. Cassidy,

    1. Department of Chemical and Biological Engineering, University of Maine Orono, ME 04469 (USA)
    Search for more papers by this author
  • William J. DeSisto

    Corresponding author
    1. Department of Chemical and Biological Engineering, University of Maine Orono, ME 04469 (USA)
    2. Laboratory for Surface Science and Technology, University of Maine Orono, ME 04469 (USA)
    • Department of Chemical and Biological Engineering, University of Maine Orono, ME 04469 (USA).
    Search for more papers by this author

  • We acknowledge the technical assistance of Nick Hill, the assistance of Scott Collins with the scanning electron microscope images, helpful discussions with Douglas Ruthven, and funding from the National Science Foundation CAREER Award 0547103.

Abstract

Mesoporous silica membranes, prepared by surfactant-templating with a pore diameter of ∼4 nm on an alumina support, are modified by atomic layer deposition (ALD) of aluminum oxide. ALD of aluminum oxide is achieved using trimethyl aluminum (TMA) and water as reactants. Membranes modified up to 50 ALD reaction cycles are characterized periodically during progressive reaction cycles to provide details of the pore modification process. A decrease in light gas permeance, pore size distribution shift to lower pore sizes, and a decrease in porosity provide evidence for pore-size reduction through ALD. Further analysis of the data indicates that the ALD reaction favors larger pores and defects, and becomes less efficient as the pore size decreases.

Ancillary