Theoretical process of rubber nano-coating on calcium silicate hydrate film for durable cementitious materials.

• Molecular dynamics simulation of rubber film nano-coating on (0 0 1) CSH surface. • Efficiency of coating with TPI (1,4- trans -Polyisoprene) and CPB (1,4-cis Polybutadiene). • A drastic decrease of the surface energy to 46.3–48.4 mJ/m2, in good agreement with experiments. • A hydrophobic behavior of rubber nano-coated on CSH surface with a contact angle in the range of 92.85° and 98.11°. • Our results found the structure of –CH = is easier to adsorb onto the (0 0 1) CSH surface. The lifetime of building materials is a significant challenge and is strongly related to their surface state and impermeability. This work is dedicated to an in-depth analysis of rubber coating process on Calcium-Silicate-Hydrate (CSH) surface. By means of molecular dynamics simulations and using a combination potential of a general force field (CLAYFF) and the consistent-valence force field (CVFF), it is found that the efficiency of coating with TPI (1,4- trans -Polyisoprene) and CPB (1,4- cis -Polybutadiene) than CPI (1,4- cis -Polyisoprene) and TPB (1,4- trans -Polybutadiene). The obtained surface energy of TPI and CPB coated CSH drastically drops from the range of 698–740 mJ/m2 to 46.3–48.4 mJ/m2. Consequently, the averaged contact angle between water nanodroplet and rubber coated CSH surface is obtained in the range of 92.85° and 98.11°, making hydrophobic the nano-coated CSH surface. The interfacial adhesion analysis between rubber film and CSH surface gives a work of adhesion in the range of 49.42 mJ / m 2 to 92.76 mJ / m 2 , in agreement with experimental measurements. [ABSTRACT FROM AUTHOR]