AVS 61st International Symposium & Exhibition
    Spectroscopic Ellipsometry Focus Topic Friday Sessions
       Session EL+AS+BI+EM+SS-FrM

Paper EL+AS+BI+EM+SS-FrM4
Polymer- and Ceramic-Supported Hybrid Gas Separation Membranes Characterized by Ellipsometry

Friday, November 14, 2014, 9:20 am, Room 304

Session: Application of SE for the Characterization of Organic and Biological Materials
Presenter: Ioannis A. Mergos, The Ohio State University
Authors: I.A. Mergos, The Ohio State University
H. Verweij, The Ohio State University
Correspondent: Click to Email
Membrane structures consist of thin continuous layers deposited on porous ceramic or polymer supports. We have been developing inorganic and hybrid membranes for various applications that include gas separation (e.g. post-combustion CO2 capture), water purification, Solid Oxide Fuel Cells (SOFC) and sensors. Spectroscopic Ellipsometry (SE) is a major non-destructive characterization tool, which can be used to obtain the thickness (typical range 50 nm…2 μm) and complex refractive index (n,k) of the supported membrane layers. This information, in turn, is used to obtain information about membrane composition, porosity and gas or water sorption. The characterization of fully-ceramic structures on optically smooth porous α-alumina surfaces (roughness ~25 nm, higher than most typical SE applications) has been employed by our group for several years. Recently we have expanded the use of SE to characterization of multi-layered membranes, and of inorganic or polymer layers on polymer supports, on coarser α alumina surfaces, and on ceramic tubes. Examples are γ- and α-alumina on polyethersulfone (PES) and poly-sulfone (PES), Ce0.9Gd0.9O1.95 on tubular α-alumina, and successive layers of amorphous microporous silica and polydimethylsiloxane (PDMS) on mesoporous intermediate layers. We have achieved signal detection and interpretation to acquire meaningful results, even in multi-layered structures and in cases with substantial interfacial of surface roughness, or curvature. Overall, the application of SE, including non-destructive characterization at intermediate stages between deposition and processing steps, can significantly facilitate the design of gas separation membrane structures that combine organic and polymer layers.