Preparation and nanotribological properties of polyelectrolyte multilayers with in situ Au nanoparticles

• Polyelectrolyte multilayers with in situ Au nanoparticles prepared by layer-by-layer and in situ reduction methods.
• The surface adhesion between the probe tip and sample surface reduced with in situ nanoparticles.
• The PAH-Au/PAA composite multilayer exhibited much lower friction force and better load-capacity.

Polyelectrolyte multilayers with in situ Au nanoparticles were prepared by alternate immersion of a substrate in poly(allylamine hydrochloride) (PAH)-AuCl4− complexes solution and poly(acrylic acid) solution for layer-by-layer self assemble process followed by reduction of the metal cations Au3+ through immersion into a fresh NaBH4 solution. UV–vis spectrum, atomic force microscopy (AFM), X-ray photoelectron spectra (XPS), and transmission electron microscope (TEM) were used to confirm the construction of multilayers and synthesis of the Au nanoparticles. The nanotribological behaviors also have been studied using AFM. The polyelectrolyte multilayers with in situ Au nanoparticles exhibited a lower surface adhesion and friction force than the pure polyelectrolyte multilayers due to the nanoparticles improved the mutilayers surface structure and possess a good load-carrying capacity in nanoscale.