Layer-by-layer deposition of polyelectrolyte nanolayers on natural fibres: cotton.

The layer-by-layer (LbL) deposition of poly(sodium 4-styrene sulfonate) (PSS) and poly(allylamine hydrochloride) (PAH) over cotton fibres is reported. Cotton fibres offer unique challenges to the deposition of nanolayers because of their unique cross section as well as the chemical heterogeneity of their surface. Cationic cotton substrates were produced by using 2,3-epoxypropyltrimethylammonium chloride. Attenuated total reflectance FTIR, x-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) were used to validate the presence of the nanolayers as well as to corroborate their self-organized structure. TEM images indicated conformal and uniform coating of the cotton fibres. XPS spectral data were found to be in quantitative agreement with previous published work that studied the LbL deposition of PSS and PAH over synthetic substrates.