화학공학소재연구정보센터
Journal of Physical Chemistry B, Vol.103, No.7, 1158-1160, 1999
Cross polarization and cross relaxation from laser-polarized xenon to surface species
The high polarization of optically pumped Xe-129 was transferred to surface carbon and silicon species under magic angle spinning (MAS) conditions to afford enhanced solid-state NMR of surfaces. High-resolution Si-29 MAS spectra of fumed silica and C-13 spectra of chemisorbcd methanol on silica were obtained using a steady flow of hyperpolarized xenon adsorbed onto the surface at 135 K. Cross polarization to Si-29 from SPINOE enhanced hydroxyl protons and to C-13 from enhanced methyl protons is observed with good efficiency. A direct SPINOE transfer from Xe-129 to C-13 without cross polarization is observed to give the highest enhancement under these conditions.