A rigid-flexible MXene/epoxy resin/hydroxy-terminated polydimethylsiloxane composite coating: Synergistic enhancement of wear resistance and hydrogen barrier of rubber seals for hydrogen infrastructure

Rubber seals were susceptible to sealing failure under prolonged wear and hydrogen permeation. In this work, a rigid-flexible MXene/epoxy resin/hydroxy-terminated polydimethylsiloxane coating was fabricated on rubber surface. Results demonstrated that NBR-MX0.2 reduced the coefficient of friction of the substrate from 0.854 to 0.116 before hydrogen exposure, and from 0.929 to 0.151 after hydrogen exposure, corresponding to reductions of 86.4% and 83.7%, and a reduction of 99.27% and 99.32% in wear rate, respectively. Besides, NBR-MX0.2 reduced the hydrogen transmission rate of the substrate to 67.9%. First-principles calculations revealed that MXene formed Ti-H bonds with dissociated hydrogen atoms, thereby suppressing hydrogen permeation through chemisorption. This work provided new insights into the development of rubber seals with excellent hydrogen compatibility for hydrogen infrastructure.