Thermal resistance effect on anomalous diffusion of molecules under confinement

Significance Diffusion is the primary process in practical multidisciplinary areas such as separation and catalysis. Transportation is usually positively correlated with temperature due to thermal motion. We show here an anomalous phenomenon wherein a higher temperature effectively slows diffusion for linear-chain hydrocarbon molecules under confinement. Such an obstruction in diffusion results from the novel mechanism of “thermal resistance effect,” in which the configuration of a guest molecule is significantly deformed with temperature effect and then strongly restrains the process of transportation in nanoscale channels at high temperature. This work will enrich our understanding of an anomalous mechanism of the diffusion phenomenon and could shed light on a fundamental understanding of the diffusion process.