10.1021/acs.iecr.6b02168.s001 Hua-Dong Huang Hua-Dong Huang Sheng-Yang Zhou Sheng-Yang Zhou Dong Zhou Dong Zhou Peng-Gang Ren Peng-Gang Ren Jia-Zhuang Xu Jia-Zhuang Xu Xu Ji Xu Ji Zhong-Ming Li Zhong-Ming Li Highly Efficient “Composite Barrier Wall” Consisting of Concentrated Graphene Oxide Nanosheets and Impermeable Crystalline Structure for Poly(lactic acid) Nanocomposite Films American Chemical Society 2016 PLA nanocomposite film impermeable PLA lamellae PLA spherulites O 2 permeability GONS region PLA film processing techniques gas barrier performance α- nucleating agent graphene oxide nanosheets spherulite morphology nucleating ability Concentrated Graphene Oxide Nanosheets high-barrier polymer packaging materials barrier performance Impermeable Crystalline Structure GONS loading packaging material crystallization rate 2016-08-19 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/Highly_Efficient_Composite_Barrier_Wall_Consisting_of_Concentrated_Graphene_Oxide_Nanosheets_and_Impermeable_Crystalline_Structure_for_Poly_lactic_acid_Nanocomposite_Films/3776676 Poly­(lactic acid) (PLA), a promising sustainable packaging material, suffers from intrinsic poor gas barrier performance partly due to its innate defect of relatively low crystallization rate. In the present study, taking advantage of the excellent impermeability and heterogeneous nucleating ability of graphene oxide nanosheets (GONSs), the crystalline structure of PLA nanocomposite film was manipulated using processing techniques. We revealed that GONSs were the α-nucleating agent for PLA, inducing typical spherulite morphology. More interestingly, two-dimensional small-angle scattering characterization confirmed that GONSs were preferentially dispersed in the amorphous phase between PLA spherulites, achieving a concentrated GONS region. As a consequence, the “composite barrier wall” consisting of concentrated GONSs and impermeable PLA lamellae gave rise to O<sub>2</sub> permeability of PLA nanocomposite film at a GONS loading of 1.0 wt % as low as 0.211 × 10<sup>–14</sup> cm<sup>3</sup> cm cm<sup>–2</sup> s<sup>–1</sup> Pa<sup>–1</sup>, reduced by ∼89.9% relative to neat amorphous PLA film. These results presented here afford new insight into the contribution of GONSs and their induced crystalline structure to the significantly enhanced barrier performance, which may also open up a promising avenue for design and fabrication of high-barrier polymer packaging materials.