掺杂Cu(OH)2纳米微粒聚电解质多层膜的摩擦磨损行为研究

采用分子沉积技术在石英和单晶硅基底上交替吸附带相反电荷的聚二烯丙基二甲基氯化铵(PDDA)和聚对苯乙烯磺酸钠(PSS)制备出初始聚电解质多层膜,在聚电解质多层膜上吸附Cu2 且与磺酸根键合于碱性溶液中水解,在聚电解质内原位生成Cu(OH)2纳米微粒,通过多次吸附-水解循环原位生成掺杂Cu(OH)2纳米微粒聚电解质多层膜.采用紫外可见吸收光谱、原子力显微镜及透射电子显微镜分析原位生成Cu(OH)2纳米微粒前后多层膜的结构与形貌,采用LKDM-2000型摩擦磨损试验机评价多层膜的摩擦磨损性能.结果表明:与初始多层膜相比,含Cu(OH)2纳米微粒聚电解质多层膜的摩擦系数有所提高,且随法向载荷的增加变化较平稳;聚电解质多层膜表现出较好的耐磨性,这是由于聚电解质多层膜内的纳米微粒提高了承载能力;薄膜的磨损机理主要为粘着磨损,由于纳米微粒的存在,可以减轻其塑性变形和粘着磨损.

Investigation of Friction and Wear Behaviors of Cu(OH)2-doped Polyelectrolyte Multilayers

Molecular deposition technology was used to prepare pristine polyelectrolyte multilayers(PEMs) by sequential adsorption Poly(diallyldimethylammonium chloride)(PDDA) and poly(sodium 4-styrenesulfonate)(PSS) alternately on quartz and Si substrate.The Cu(OH)_2-doped polyelectrolyte multilayers were achieved using a series of cyclical adsorption-hydrolysis processess in which copper ions bind to the sulfonate groups of the pristine PEMs and then hydrolysis in an alkali solution.UV-vis absorption spectroscopy,atomic force microscopy and transmission electron microscopy were used to observe the structure and the morphology of before and after the in-situ synthesis copper hydroxide nanoparticles in the PEMs matrix.Tribological behaviors of the Cu(OH)_2-doped polyelectrolyte multilayers were studied on the LKDM-2000 tribology measurement apparatus,and results show that friction coefficient of the Cu(OH)_2-doped polyelectrolyte multilayers is higher and has no obvious change with increase of normal load compared with pristine PEMs.Cu(OH)_2-doped polyelectrolyte multilayers exhibit higher durability,because the inorganic nanoparticles in the PEMs enhanced load-carrying capacity.The main wear mechanism is adhesive wear,and Cu(OH)_2 nanoparticles in the PEMs mitigated plastic deformation and slowed down adhesive wear owing to their existence.