Fast and robust quantification of liquid inside thin fibrous porous materials with single-sided NMR

Single-sided NMR with the NMR-MOUSE is employed for the characterization of fluids in fibrous and open foam materials. One of the key aspects of this study is the quantification of the fluid amount. To this end critical information was provided by a relaxation study. Using 2 mM/L of a Gd³⁺ relaxation agent the repetition time could be shortened to 250 ms, improving the correlation coefficient between liquid amount and signal amplitude from R² = 0.893 to R² = 0.982. To assess reproducibility and instrument precision, calibration experiments were repeated several times and their variation investigated. The results showed that the device is highly precise and robust with a standard deviation for liquid quantification of less than 1%.