Explaining high flow rate of water in carbon nanotubes via solid–liquid molecular interactions

Experimental and simulation measurements of water flow through carbon nanotubes have shown orders of magnitude higher flow rates than what was predicted using continuum fluid mechanics models. Different explanations have been offered, from slippage of water on the hydrophobic surface of the nanotubes to size confinement effects. In this work a model capable of explaining these observations, linking the enhanced flow rates observed to the solid–liquid molecular interactions at the nanotube wall is proposed. The model is capable of separating the effects on flow enhancement of the tube characteristic dimensions and the solid–liquid molecular interactions, accurately predicting the effect of each component for nanotubes of different sizes, wall surface chemistry and structure. Comparison with the experimental data available shows good agreement.