Clay-chitosan nanobrick walls: completely renewable gas barrier and flame-retardant nanocoatings. Academic Article uri icon


  • Thin films prepared via a layer-by-layer (LbL) assembly of renewable materials exhibit exceptional oxygen barrier and flame-retardant properties. Positively charged chitosan (CH), at two different pH levels (pH 3 and pH 6), was paired with anionic montmorillonite (MMT) clay nanoplatelets. Thin-film assemblies prepared with CH at high pH are thicker, because if the low polymer charge density. A 30-bilayer (CH pH 6-MMT) nanocoating (~100 nm thick) reduces the oxygen permeability of a 0.5-mm-thick polylactic acid film by four orders of magnitude. This same coating system completely stops the melting of a flexible polyurethane foam, when exposed to direct flame from a butane torch, with just 10 bilayers (~30 nm thick). Cone calorimetry confirms that this coated foam exhibited a reduced peak heat-release rate, by as much as 52%, relative to the uncoated control. These environmentally benign nanocoatings could prove beneficial for new types of food packaging or a replacement for environmentally persistent antiflammable compounds.

published proceedings

  • ACS Appl Mater Interfaces

altmetric score

  • 12

author list (cited authors)

  • Laufer, G., Kirkland, C., Cain, A. A., & Grunlan, J. C.

citation count

  • 292

complete list of authors

  • Laufer, Galina||Kirkland, Christopher||Cain, Amanda A||Grunlan, Jaime C

publication date

  • March 2012