分子沉积聚合物膜的制备及其摩擦学性能研究

以聚对磺酸钠苯乙烯(PSS)为聚阴离子、聚烯丙基氯化氨(PAH)为聚阳离子交替沉积制备了多层聚合物纳米复合膜,用热分析仪考察了这两种体相聚合物的热稳定性,采用紫外-可见光谱仪、椭圆偏振光测厚仪、接触角测量仪等分析了复合膜的性能,用DF-PM型动静摩擦系数精密测定装置考察了其摩擦学性能.结果发现,所制备的聚合物复合膜具有一定的减摩作用,原因是单晶硅表面沉积聚合物超薄膜可以降低表面的粘着力,对硅表面具有微观修饰作用,从而降低其同钢对摩时的摩擦系数;单晶硅表面分子沉积聚合物纳米复合膜的摩擦学特性同超薄膜的层数相关,沉积层数较多的超薄膜的耐磨寿命较长,并因加热处理而得到明显改善.

Molecular Deposition Polymeric Nanocomposite Films and Their Tribological Properties in Sliding against Steel

Multilayer polymeric nanocomposite films were prepared by alternative deposition of poly(sodium 4-styrenesulfonate) (coded as PSS) as polycation and poly(allyamine hydrochloride) (coded as PAH) as polyanion. Thermal gravimetric analysis was used to examine the bulk thermal stability of the polymers, while UV-visible absorption spectrometry, ellipsometry measurement and contact angle measurement were conducted to characterize the films. The friction and wear behavior of the polymer ultra-thin films sliding against SAE-52100 steel was examined on a DF-PM ball-on-block one-way reciprocating friction and wear test rig, with emphasis on the effect of heat-treatment of the tribological behavior of the films. As the results, the tested polymeric molecular deposition films records reduced friction coefficient. The friction reduction effect of ultrathin films is attributed to surface adhesion reduction and surface micro-modification. Therefore it reduces the friction coefficient of silicon single crystal sliding against SAE-52100 steel. Tribological behavior of polymeric nanocomposite films on silicon single crystal is correlative with the number of bilayers. The antiwear life of the molecular deposition films with more number of bilayers is longer than fewer bilayer films. Their antiwear life is considerably increased after proper heat-treatment.