Appl. Magn. Reson. 22, 175-186 (2002) Applled Magnetic Resonance 9 Springer-Verlag 2002 Printed in Austria Spatially Resolved Adsorption Isotherms of Thermally Polarized Perfluorinated Gases in Yttria-Stabilized Tetragonal-Zirconia Polycrystal Ceramic Materials with NMR Imaging S. D. Beyea l, A. Caprihan 1, C. E M. Clewett I, and S. J. Glass 2 t New Mexico Resonance, Albuquerque, New Mexico, USA 2SandŸ National Laborato¡ Albuquerque, New Mexico, USA Received September 5, 2001; revised December 18, 2001 Abstract. This paper presents the results obtained by nuclear magnetic resonance (NMR) imaging of perfluorinated gases in mesoporous solids. NMR images of nuclear spin density a s a function of gas pressure permits spatially resolved measurements that are analogous to conventional bulk Brunauer- Emmett-Teller adsorption isotherm measurements. The use of NMR imaging allows the nondestruc- tive evaluation of macroscopic spatial variations in the underlying mesoporous structure, for materi- als such as partially sintered Y-TZP (ytt¡ tetragonal-zirconia polycrystal) ceramics. All NMR measurements were performed with octafluorocyclobutane (C4F8) gas, using only the thermal Boltzman nuclear magnetization. 1 Introduction Nuclear magnetic resonance (NMR) is a well established and useful method for studying porous media, due to its sensitivity to parameters such as porosity, pore radius, tortuosity and phase state [1-4]. Generally, studies have focused on liq- uids in porous materials such as rocks and soils. NMR of hyperpolarized 129Xe gas has also recently been used to study po- rous solids [5]. In these studies, the ability to produce a large nuclear magneti- zation is used to overcome the inherently small spin density of gases, so as to allow NMR measurements of the time-dependent diffusion coefficient, and hence the tortuosity of the underlying pore structure. These measurements generally require that the 129Xe molecules do not significantly interact with the solid pore matrix, as these interactions often act to rapidly return the hyperpolarization to its equilibrium Boltzman value. The study of how gases interact with porous materials is, however, an im- portant area of scientific research. Studies of gas/liquid phase equilibria in po- rous solids provide information on the physics of finite-size effects and surface