Exploration of saturated transport of ion concentration differences in C–S–H channels

Understanding the diffusion behavior of solutions containing aggressive ions in saturated C–S–H nanopores is of significant importance. This simulation provides unprecedented microscopic images that reproduce the transport of solutions in saturated C–S–H channels based on molecular dynamics. Specifically, we show that the diffusion behavior of aggressive ions is hindered in saturated pore channels compared to unsaturated transport processes, leading to their reduced permeability. Due to the electrical double layers effect, The NaCl solution invasion in C–S–H nanopores is faster compared to the overflow of aqueous solutions. The hydration shells of anions and cations undergo different changes during the intrusion of ions into the C–S–H nanopores. For chloride ions with larger hydration shell radius, the adsorption capacity of the anion is significantly weakened with increasing pore size. While the hydration shell of sodium ions is more derived from the water molecules in the NaCl and is more easily hindered by the overflow of the aqueous solution in the saturated nanopore.