Figure 8. (A) Schematic diagram of the hydrogen bond networks in the (TA@LDH/PEO)n films; (B) Reorientation of LDH nanosheets to perfect parallel alignment after stretching.
Whether upon repeated stretching or at a high stretching ratio, the (TA@LDH/PEO)50 film keeps very good oxygen barrier performance. Many factors make it have good oxygen resistance and stretchable ability. LDH, TA and PEO all have plentiful hydrogen bonding sites. When the film deformation is small, the H-bonding between TA@LDH and PEO has much higher bond strength than van der Waals forces between PEO chains, so the deformation is more likely to be a result of PEO chain segment reorientation and extension rather than breaking hydrogen bonds. In the process of further stretching, hydrogen bond damage and regeneration of the film occur continuously (Figure 8A). In addition, some LDH nanosheets that are not strictly parallel to the substrate will reorient after stretching to improve the oxygen barrier capability of the film (Figure 8B). Therefore, the (TA@LDH/PEO)50 film simultaneously shows good barrier property and excellent stretchability.