FIGURE 1.

Temperature dependence of ²³Na NMR in 100 mM NaCl solution. (a) 1D ²³Na NMR spectra reveal temperature‐dependent ²³Na chemical shift changes and broadening. (b) The ²³Na longitudinal relaxation (R ₁) rates obtained from inversion‐recovery data at different temperatures (shown in Figure S1). The dashed line (dark red) shows the expected trend of R1 changes calculated based on the η/T ratio variation. The error bars are smaller than the symbol size. (c) Temperature dependence of ²³NaCl translational diffusion coefficients (Dtr) obtained through PFG‐NMR diffusion experiments. The temperature‐dependent changes in Dtr is more pronounced than the expected trend calculated based on the T/η ratio variation (dashed line in dark red). PFG, pulse field gradient