One-step procedure for the preparation of functional polysaccharide/fatty acid multilayered coatings

Soft, stratified, amphiphilic systems are recurrent motifs in nature, e.g., in myelin sheaths or thylakoid stacks, and synthetic analogues are increasingly being exploited in the areas of biocatalysis, biosensing, and drug delivery. The synthesis of such complex multilayered systems usually requires lengthy preparation protocols. Here, we demonstrate the formation of multilayered fatty acid/polysaccharide thin films prepared via a single step protocol, which exploits the spontaneous self-assembly of the components into vesicular systems in aqueous solution. The solutions are characterized by light and neutron scattering experiments and the thin films by neutron reflectometry, optical ellipsometry, atomic force microscopy, and x-ray diffraction. The thin films exhibit structural features with sub-10 nm dimensions, stemming from the ordered sequence of hydrophilic and hydrophobic layers and respond strongly to changes in ambient humidity. Using this approach, films with a total thickness varying from tens to hundreds of nanometers can be easily prepared.