NMR_T2_evaporation-of-water_porous-media

Nuclear magnetic resonance (NMR) transversal relaxation time T2 during evaporation of water from porous media was collected. Both homogeneous and inhomogeneous porous media was applied in experiments. Homogeneous porous media was made of uniform-sized glass beads with diameter at either 25 μm or 150 μm. Inhomogeneous porous media included two parts with top and bottom part made of fine and coarse beads respectively. By adjusting the proportion of each part, multiple inhomogeneous porous media was made. The temperature during experiment was controlled at 50 °C and T2 data was recorded every 30 minutes (individual experiment lasted from 3 to 5 days). Carr-Purcell-Meiboom-Gill (CPMG) sequence was applied in data recording and parameters were set at TE=0.2 ms and NECH=18000. Each recording collects 5000 pairs of T2 and corresponding signal amplitude, based on which the transient water content and distribution could be obtained.