Self-Diffusion:
The self-diffusion measurements were carried out with a 20 MHz minispec bench-top pulsed NMR analyzer (Bruker Analytic GmbH, Germany), equipped with a permanent magnet, and a 10-mm temperature controlled probe head. Prior to each measurement, the samples were stabilized at 40 °C for 40 min and then allowed to equilibrate inside the instrument for 5 min (Meiri et al., 2015). The self-diffusion coefficient, D, was determined by the pulsed-field gradient spin echo (PFGSE) method (Stejskal and Tanner, 1965). The pulse sequence was used with 16 scans, τ  of 7.5 ms, and a recycle delay of 6 s. Typical gradient parameters were Δ  of 7.5 ms, δ  of 0.5 ms, time between the 90° pulse to the first gradient pulse of 1 ms, and G  of 1.6 T/m. Each reported self-diffusion coefficient (D) value is the average of ten measurements.