Transparency, gas barrier and moisture resistance of large aspect ratio vermiculite nanobrick wall thin films
The ability to incorporate large-aspect-ratio vermiculite (VMT) clay into thin ﬁlms fabricated using the layer-by-layer assembly techinique is reported for the ﬁrst time. Thin ﬁlms of branched polyethylenimine (PEI) and VMT were analyzed for their growth rate, clay composition, transparency, and gas barrier behavior. These ﬁlms consist of >96 wt % clay, are >95% transparent, and, because of their nanobrick wall structure, exhibit super gas barrier behavior at thicknesses of <165 nm. When coupled with ﬂexibility, the optical clarity and super barrier that these coatings can impart make them superb candidates for a variety of packaging applications.
Priolo, MA; Holder, KM; Greenlee, SM; Grunlan, JC; ACS Appl. Mater. Interfaces, 2012, 4, 5529-5533.