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∗ Corresponding authors. Phone: +86-10-64412131. Fax: +86-10-64425385. E-mail: hanjb@mail.buct.edu.cn.
Abstract: Stretchable gas barrier films hold great application potentials in flexible electronics, sensors and food/drug packaging. 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 fifty-bilayer TA@LDH/PEO film (865 nm thick), 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. This work provides a simple and cost-effective strategy for the preparation of nanosheets-based hybrid materials, which are useful in those fields requiring simultaneously high gas barrier and good flexibility.
KEYWORDS: films, membrane materials, two-dimensional nanosheets, gas barrier,
hydrogen bonds assembly