Time-domain NMR study of the drying of hemicellulose extracted aspen (Populus tremuloides Michx.)
The effect of hot water on aspen chips has been evaluated using time-domain low-field nuclear magnetic resonance (NMR) spectroscopy. At moisture contents above fiber saturation point, treated chips exhibit relaxation times of free water longer than for the control. This is consistent with the removal of hemicelluloses given the hydrophilicity of these polysaccharides. The rate of decrease in free water upon drying is greater for the pretreated samples. These results indicate that hot water treatment modifies both the chemical and physical properties of the chips and may therefore impact product manufacture and performance.