Preparation of microporous films with sub nanometer pores and their characterization using stress and FTIR measurements
- Sandia National Labs., Albuquerque, NM (United States)
- Sandia National Labs., Albuquerque, NM (United States). Ceramic Processing Science Dept.
The authors have used a novel technique, measurement of stress isotherms in microporous thin films, as a means of characterizing porosity. The stress measurement was carried out by applying sol-gel thin films on a thin silicon substrate and monitoring the curvature of the substrate under a controlled atmosphere of various vapors. The magnitude of macroscopic bending stress developed in microporous films depends on the relative pressure and molar volume of the adsorbate and reaches a value of 180 MPa for a relative vapor pressure, P/Po = 0.001, of methanol. By using a series of molecules, and observing both the magnitude and the kinetics of stress development while changing the relative pressure, they have determined the pore size of microporous thin films. FTIR measurements were used to acquire adsorption isotherms and to compare pore emptying to stress development, about 80% of the change in stress takes place with no measurable change in the amount adsorbed. The authors show that for sol-gel films, pore diameters can be controlled in the range of 5--8 {angstrom} by ``solvent templating``.
- Research Organization:
- Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States); National Science Foundation, Washington, DC (United States)
- DOE Contract Number:
- AC04-94AL85000
- OSTI ID:
- 244629
- Report Number(s):
- SAND-96-1279C; CONF-960401-36; ON: DE96010536; TRN: AHC29613%%104
- Resource Relation:
- Conference: Spring meeting of the Materials Research Society (MRS), San Francisco, CA (United States), 8-12 Apr 1996; Other Information: PBD: [1996]
- Country of Publication:
- United States
- Language:
- English
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