Proton spin relaxation study of methanol absorbed on cellulose

Abstract

The proton NMR relaxation times T1, T1p and T2 have been measured as a function of temperature between 383 K and 133 K for cellulose saturated with methanol. The resonance frequency was 30 MHz and the spin locking field pulse strength used to measure T1p was 10 Gauss. T1 shows a single component at all temperatures. T1p displays two components and T2 displays three components. The three components are attributed to protons on the cellulose molecule, protons on methanol molecules hydrogen bonded at the OH sites of the cellulose and protons on methanol molecules hydrogen bonded at the CH 20H sites of the cellulose. The temperature dependence of T1 is consistent with relaxation dominated by reorientation of the CH 3 group of the methanol molecules, with a broad distribution of correlation times.