Grand canonical Monte Carlo and molecular dynamics investigation of hydrogen solubility and diffusivity in nonmetallic polyvinyl chloride, polyethylene and polyvinylidene fluoride pipes materials

To choose appropriate nonmetallic pipe materials for reducing hydrogen permeation, the hydrogen permeability in polyvinyl chloride, polyethylene, and polyvinylidene fluoride are studied and compared by molecular dynamics simulations. The findings demonstrate the solubility coefficient of hydrogen in polyvinyl chloride rises as the temperature decreases. However, in polyethylene and polyvinylidene fluoride, the trend is reversed. With the decrease of temperature, the diffusion and permeability coefficients decrease. The diffusion of hydrogen molecules follows the jumping mechanism. Among the materials studied, polyvinylidene fluoride is the most suitable material for hydrogen pipes due to its superior resistance to hydrogen permeation.