Coarse Grained simulations were run using the MARTINI forcefield v2.2. Non-bonded interactions were shifted to zero with the use of potential-modifiers at the cutoff distance of 1.1 nm. The combined use of the Verlet neighbor list algorithm and GROMACS v5 running on GPUs lead to a good performance. Pressure and temperature coupling schemes were maintained similar as in the atomistic simulations. The relative permittivity was set to 15 and time step of 10 fs was used if not otherwise specified. ammine-PEG 550 Da and 1,000 Da were purchased from creative PEG-works.