Fabrication and tribological properties of polyelectrolyte multilayers containing in situ gold and silver nanoparticles

Gold and silver nanoparticles in polyelectrolyte multilayers film can be prepared by alternate immersion of a substrate in poly(diallyldimethylammonium) chloride (PDDA)–AuCl4− complexes solution and poly(acrylic acid) (PAA)–Ag+ complexes solution followed by reduction of the metal cations (Au3+, Ag+) through immersion of NaBH4 solution. UV–vis spectroscopy, atomic force microscopy (AFM), X-ray photoelectron spectra (XPS), scanning electron microscope (SEM) and transmission electron microscope (TEM) were used to confirm the successful construction of the polyelectrolyte multilayers film and the formation of gold and silver nanoparticles. The coefficient of friction as a function of sliding velocity and normal load also has been studied. The nanoparticles composite polyelectrolyte multilayers exhibited increased wear resistance compared with the pure polyelectrolyte multilayers.

Schematic of the layer-by-layer buildup and gold and silver nanoparticles formation process.Figure optionsDownload as PowerPoint slideHighlights
► Au and Ag nanoparticles were synthesized by in situ reduction.
► PEMs were prepared by layer-by-layer and in situ reduction methods.
► PDDA–Au/PAA–Ag PEMs possesses a lower friction coefficient.
► PDDA–Au/PAA–Ag PEMs has longer anti-wear life than the pure PEMs.