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.

Two-phase channel structures based on alpha-cyclodextrin-polyethylene glycol inclusion complexes.

Wide-angle X-ray scattering observations of alpha-cyclodextrin (CD)-poly(ethylene glycol) (PEG) inclusion complexes (ICs) have shown for the first time that two crystalline columnar modifications (forms I and II) are produced in the process of their formation. This was made possible by precise azimuthal X-ray diffraction scanning of oriented IC samples. Form I is characterized by CDs threaded onto PEG chains and arranged along channels in the order head-to-head/tail-to-tail, while form II is formed by unbound CDs also arranged into columns in a head-to-tail and also possibly a head-to-head/tail-to-tail manner, probably as a result of template crystallization on the form I IC crystals.