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.