[19p-P1-1~10] 1.5 Instrumentation, measurement and Metrology

[19p-P1-4] Characterization of mesoporous silica membrane using hyperpolarized gas NMR

〇Mineyuki Hattori¹ (1.NMIJ AIST)

Keywords:NMR, hyperpolarization, porous media

¹²⁹Xe NMR spectra of natural abundant xenon gas trapped in fully dehydrated mesoporous materials with pore sizes smaller than 2 nm in diameter were observed under atmospheric pressure in the temperature range between 168 and 373 K. The diameters of three porous materials studied in this paper were 0.5, 1 and ~ 2 nm for molecular sieves 5A and 13X and synthesized mesoporous silica, respectively. The samples were fully dehydrated using an ultra-high vacuum (UHV) system and xenon gas was introduced into pre-cooled state at 168 K just above the boiling point of xenon. The ¹²⁹Xe NMR spectra were observed by increasing temperature and the ¹²⁹Xe shift, line width and area intensity were observed at each temperature for the three samples under atmospheric pressure. The behaviors of xenon atoms in small pores observed in equilibrium states can provide important information on relationships between the pore structure and ¹²⁹Xe chemical shift.