Preparation of ultrathin membranes by layer-by-layer deposition of layered double hydroxide (LDH) and polystyrene sulfonate (PSS)

Nanofilms were prepared by consecutively alternating adsorption of Mg–Al (2:1) layered double hydroxide (LDH) and polysodium 4-styrenesulfonate (PSS). The charge density of oppositely charged materials strongly affect film properties like thickness and ordering. The specific charge of the colloid particles (LDH) and macromolecules was determined with the particle charge detector. The sequential build-up of the thin films was followed by spectrophotometry and X-ray diffraction. The surface morphology of the multilayers was characterized by atomic force microscopy. The influence of the charge density of the applied materials and of the mass ratio of LDH/PSS on the film thickness were studied.