Investigation of tribological behavior of lanthanum hybrid polyelectrolyte molecular deposition films

Poly(allylamine hydrochloride) (PAH) and poly(styrene sulfonic acid) sodium salt (PSS) polyelectrolyte molecular deposition films were prepared on quartz substrate by the layer-by-layer method. Lanthanum was deposited in the polyelectrolyte molecular deposition film, making use of the chemisorption ability of –SO3− group of PSS, and heating for 2 h at 120 °C to make the lanthanum element chemically bond with PSS. Atomic force microscopy (AFM), ultraviolet–visible (UV–vis) light spectroscope, X-ray photoelectron spectroscopy (XPS), and contact angle measurements were used to characterize the thin films. The tribological behaviors of the polyelectrolyte molecular deposition film and lanthanum hybrid polyelectrolyte molecular deposition film were evaluated on a micro-tribometer by sliding against a steel ball. Tribological experiments show that the friction coefficient of polyelectrolyte molecular deposition film decreases from 0.19 to 0.08 after the rare-earth (RE) self-assembled in the polyelectrolyte molecular deposition film. The lanthanum hybrid polyelectrolyte molecular deposition films have a longer wear life than that for the pure polyelectrolyte molecular deposition film. It is demonstrated that the lanthanum hybrid polyelectrolyte molecular deposition film exhibits a good wear-resistant property.