Molecular deposition films were prepared on substract by alternative deposition of poly(sodium 4-styrenesulfonate) as polyanion and poly(diallyldimethylammonium chloride) as polycation.The order thin films were characterized by using ultraviolet-visible absorption spectrometry,contact angle measurement and atomic force microscopy.The friction and wear behavior of polymer ultra-thin films sliding against stainless steel was examined on UMT-2.As the results,the ultra-thin films show good friction-reducing and...