The dynamic viscosity η of the PEG-H 2 O mixtures was determined for increasing PEG concentration c PEG using the non-equilibrium method of Hess et al. . Our results show an increase of η by a factor of about 30 when increasing c PEG from 0.01 to 100, in good agreement with experimental results from Jora et al. (Fig. ). The steepest increase occurs for intermediate PEG concentration (c PEG ≈ 1), corresponding to the semi-dilute regime where the interaction between PEG molecules are non negligible . In the diluted regime c PEG → 0, one recovers the viscosity of pure water, η → 1 mPa • s. In the concentrated regime c PEG > 10, the viscosity of the AA simulation is 40±10 mPa•s, which is only slightly lower than the experimental viscosity of 50 ± 5 mPa • s. Then, the NMR relaxation rate R 1 was calculated using Eqs. (2-5). Our results obtained using AA calculations show that R 1 increases for increasing PEG concentration c PEG (Fig. ). As c PEG increases from 0.01 to 100, R 1 increases by a factor of about 20, in good agreement with the experimental results from Ref. . In the diluted limit, c PEG → 0, R 1 → 0.3 s -1 , as expected for bulk water at temperature T = 298.15 K . Overall, the good agreement between our simulations and the experimental results of Ref. serves as a validation of the employed atomistic force field and molecular dynamics simulation protocol, as well as a validation of the measurement methods for η and R 1 .