Preparation of functionalized MXene-stitched-graphene oxide/poly (ethylene-co-acrylic acid) nanocomposite with enhanced hydrogen gas barrier properties

The storage of H₂ is one of the critical issues to be resolved to expand H₂-based energy. Herein, MXene was employed in combination with GO for the first time for H₂ gas barrier coating on nylon 6 substrate (commonly used in storage tanks). A facile two-step method was acquired to covalently bond MXene and GO through 3-aminopropyl triethoxysilane (APTES) by employing carbodiimide reaction. The MXene-GO hybrid nanofiller (f-MXene-GO) exhibited a higher gallery gap between the nanosheets than that of the pristine MXene and GO. Besides, GO was also partially reduced by the amine functional groups of APTES. To the best of our knowledge, the stitching of MXene and GO using APTES has not yet been discussed in the literature. When f-MXene-GO was dispersed in poly (ethylene-co-acrylic acid) (EAA), a significant improvement in the mechanical properties was observed. An increase in the gallery gap between the MXene layers in f-MXene-GO/EAA nanocomposite as compared to MXene/EAA suggested the effectiveness of APTES grafting to enhance the interaction with EAA. MXene/EAA exhibited a higher H₂ gas barrier and mechanical properties than GO/EAA, whereas the adhesion of MXene/EAA to the nylon 6 substrate was weak. f-MXene-GO/EAA exhibited a judicious combination of both barrier and adhesion properties. The 10 wt% f-MXene-GO/EAA coated layer showed a very low H₂ permeability coefficient (0.03 cc.mm.m⁻².d⁻¹.atm⁻¹) and a significant 89% reduction in the H₂ gas transmission rate with respect to nylon 6.