Stretchable gas barrier films achieved by hydrogen-bond self-assembly of nano-brick multilayers

Inorganic–organic hybrid films containing two-dimensional nanosheets have shown good gas barrier performance, but moderate tensile property, because of the rigid characteristics of covalent or ionic bonds between the assembly units. In this work, we used LDH nanosheets rich in hydroxyl groups as building units, followed by modification of tannic acid (TA), to assemble with polyethylene oxide (PEO) through hydrogen bonds. Compared with previous work, the tensile property and oxygen barrier performance of (TA@LDH/PEO) n films have been significantly improved. A 50-bilayer TA@LDH/PEO film, deposited on a 1 mm thick natural rubber substrate, results in a 29× reduction (contrast with bare substrate) in oxygen transmission rate and maintains its good barrier property even under a large elongation of 120%. The excellent tensile and gas barrier properties are attributed to the ductility of hydrogen bond network among building blocks and the significant prolongation of oxygen transmission path induced by LDH nanosheets.