title: Sandwich-Architectured Poly(lactic acid)-Graphene Composite Food Packaging Films.
abstract: Biodegradable food packaging promises a more sustainable future. Among the many different biopolymers used, poly(lactic acid) (PLA) possesses the good mechanical property and cost-effectiveness necessary of a biodegradable food packaging. However, PLA food packaging suffers from poor water vapor and oxygen barrier properties compared to many petroleum-derived ones. A key challenge is, therefore, to simultaneously enhance both the water vapor and oxygen barrier properties of the PLA food packaging. To address this issue, we design a sandwich-architectured PLA-graphene composite film, which utilizes an impermeable reduced graphene oxide (rGO) as the core barrier and commercial PLA films as the outer protective encapsulation. The synergy between the barrier and the protective encapsulation results in a significant 87.6% reduction in the water vapor permeability. At the same time, the oxygen permeability is reduced by two orders of magnitude when evaluated under both dry and humid conditions. The excellent barrier properties can be attributed to the compact lamellar microstructure and the hydrophobicity of the rGO core barrier. Mechanistic analysis shows that the large rGO lateral dimension and the small interlayer spacing between the rGO sheets have created an extensive and tortuous diffusion pathway, which is up to 1450-times the thickness of the rGO barrier. In addition, the sandwiched architecture has imbued the PLA-rGO composite film with good processability, which increases the manageability of the film and its competency to be tailored. Simulations using the PLA-rGO composite food packaging film for edible oil and potato chips also exhibit at least eight-fold extension in the shelf life of these oxygen and moisture sensitive food products. Overall, these qualities have demonstrated the high potential of a sandwich-architectured PLA-graphene composite film for food packaging applications.
authors.affiliation: Interdisciplinary Graduate School, Nanyang Technological University , 639798 Singapore.|Singapore Membrane Technology Center, Nanyang Environment and Water Research Institute, Nanyang Technological University , 637141 Singapore.|School of Chemical and Biomedical Engineering, Nanyang Technological University , 637459 Singapore.
authors.forename: Kunli
authors.initials: K
authors.lastname: Goh
authors.affiliation: Food Quality and Design Group, Department of Agrotechnology and Food Sciences, Wageningen University , P.O. Box 17, 6700 AA Wageningen, The Netherlands.
authors.forename: Jenneke K
authors.initials: JK
authors.lastname: Heising
authors.affiliation: School of Chemical and Biomedical Engineering, Nanyang Technological University , 637459 Singapore.
authors.forename: Yang
authors.initials: Y
authors.lastname: Yuan
authors.affiliation: School of Chemical and Biomedical Engineering, Nanyang Technological University , 637459 Singapore.
authors.forename: Huseyin E
authors.initials: HE
authors.lastname: Karahan
authors.affiliation: School of Chemical and Biomolecular Engineering, The University of Sydney , Sydney, New South Wales 2006, Australia.
authors.forename: Li
authors.initials: L
authors.lastname: Wei
authors.affiliation: School of Chemical and Biomedical Engineering, Nanyang Technological University , 637459 Singapore.|School of Chemical and Biomolecular Engineering, The University of Sydney , Sydney, New South Wales 2006, Australia.
authors.forename: Shengli
authors.initials: S
authors.lastname: Zhai
authors.affiliation: School of Chemical and Biomedical Engineering, Nanyang Technological University , 637459 Singapore.
authors.forename: Jia-Xuan
authors.initials: JX
authors.lastname: Koh
authors.affiliation: Hwa Chong Institution , 269734 Singapore.
authors.forename: Nanda M
authors.initials: NM
authors.lastname: Htin
authors.affiliation: Hwa Chong Institution , 269734 Singapore.
authors.forename: Feimo
authors.initials: F
authors.lastname: Zhang
authors.affiliation: Singapore Membrane Technology Center, Nanyang Environment and Water Research Institute, Nanyang Technological University , 637141 Singapore.
authors.forename: Rong
authors.initials: R
authors.lastname: Wang
authors.affiliation: Singapore Membrane Technology Center, Nanyang Environment and Water Research Institute, Nanyang Technological University , 637141 Singapore.
authors.forename: Anthony G
authors.initials: AG
authors.lastname: Fane
authors.affiliation: Food Quality and Design Group, Department of Agrotechnology and Food Sciences, Wageningen University , P.O. Box 17, 6700 AA Wageningen, The Netherlands.
authors.forename: Matthijs
authors.initials: M
authors.lastname: Dekker
authors.affiliation: School of Chemical and Biomolecular Engineering, The University of Sydney , Sydney, New South Wales 2006, Australia.
authors.forename: Fariba
authors.initials: F
authors.lastname: Dehghani
authors.affiliation: School of Chemical and Biomolecular Engineering, The University of Sydney , Sydney, New South Wales 2006, Australia.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Chen
mesh_terms: D003198:Computer Simulation; D018857:Food Packaging; D006108:Graphite / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D010100:Oxygen / Q000737:chemistry; D011091:Polyesters / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman; D013227:Steam; D014961:X-Ray Diffraction
chemical_list: D011091:Polyesters; D013227:Steam; C033616:poly(lactide); D006108:Graphite; D010100:Oxygen
keywords: food packaging; graphene oxide; oxygen permeability; poly(lactic acid); shelf-life simulations; water vapor permeability