Nanobrick walls provide super gas barrier

The topic of this newly published journal paper, lead author Morgan A. Priolo, discusses the latest progress in gas barrier technology from the PNC Lab. A 51 nm thick, fully transparent film provides super gas barrier properties that are potentially applicable in food, electronic and pharmaceutical packaging.

These transparent, flexible thin films are fabricated with layer-by-layer assembly (LbL), which is a dipping cycle consisting of a substrate being dipped into alternating cationic and anionic deposition solutions, with spray-rinsing and drying between each deposition. This paper highlights a new quadlayer (QL) system composed of three polymers and a capping clay layer – catioinic polyethylenimine (PEI) and anionic montmorillonite clay (MMT) and poly(acrylic acid) (PAA) – in the dipping sequence PEI/PAA/PEI/MMT.

Layer-by-layer assembly schematic.
Layer-by-layer assembly schematic.

LbL assembly of polymer and clay creates a nano brick wall structure that forms a highly tortuous path, resulting in a transparent, super gas barrier exhibiting an oxygen permeability orders of magnitude lower than EVOH and SiOx.


Lowest oxygen permeability ever reported for any thin film material! (≤ 5 x 10-22 cm3(STP)·cm/cm2·s·Pa).


poster - super O barrier