PDDA/Au NPs复合分子沉积膜的制备、表征和摩擦学行为  

Fabrication Characterization and Tribological Behaviors of PDDA/Au NPs Composite Molecular Deposition Films

作　　者：肖宇琦[1] 王德国[1] 张嗣伟[1] 高芒来[2] 

机构地区：[1]中国石油大学(北京)机电工程学院,北京102249 [2]中国石油大学(北京)化学科学与工程学院,北京102249

出　　处：《纳米技术与精密工程》2008年第3期164-169,共6页Nanotechnology and Precision Engineering

基　　金：国家自然科学基金资助项目(50575151);国家重点基础研究发展计划(973)项目(2007CB607604);清华大学摩擦学国家重点实验室开放基金资助项目(SKLT05-02)

摘　　要：采用小分子柠檬酸钠对金纳米粒子进行包覆改性,紫外光谱分析经改性的金纳米粒子表面共振吸收峰为526,nm,激光纳米粒度仪分析表明其平均粒径为8.4,nm.改性后的金纳米粒子通过分子沉积技术,与聚二烯丙基二甲基胺盐酸盐(PDDA)组装,制得单层和多层PDDA/AuNPs复合纳米粒子分子沉积(MD)膜(简称PDDA/Au NPs复合MD膜).采用原子力显微镜(AFM)研究了PDDA/Au NPs复合MD膜的表面形貌以及摩擦、磨损行为.研究结果表明:该复合膜能降低基底的摩擦力,其中以3层膜降低摩擦力的效果最显著.在氮化硅探针扫描行程达到30次后,膜表面才开始出现磨损痕迹.随着扫描次数的增多,膜表面在探针剪切力的作用下逐渐由致密变得疏松,形成颗粒堆积,使表面粗糙度增大,摩擦力、磨损深度也随之增加.通过实验还发现这种复合膜存在两种非正常磨损现象,即磨损负增长和膜的脱落现象.Poly （ diallyldimethylammonium chloride ） / sodium citrate-enwrapped gold nanoparticles （ PDDA/Au NPs ） composite molecular fills were prepared by molecular deposition （ MD ） method, which is used to assemble the monolayer and multilayer fills in nanoscale by way of intermolecular electrostatic forces. The encapsulated gold nanoparticles with about 8.4 nm in diameter assembled in the fills were fabricated by sodium citrate reduction of gold chloride in ultrasonic field using sodium borohydride as a catalyst. The surface plasmon absorption of the gold colloid solution centered at 526 nm, and the average radius of the nanoparticles was determined by the laser granularity equipment. The uniform structure of the fills was analyzed by ultraviolet-visible （ UV ） spectroscopy and the nanotribological properties of them were examined by atomic force microscope （ AFM ） . It was found that these fills had a much smaller friction force than their substrates and the friction force of the tri-layer fill was smaller than that of the other multilayer films. Wear mark became apparent until the scan cycles were more than 30. The fine and compact surface texture of the MD fill deposited on the substrate became loose under the action of the shear force of the tip. And the nanoparticles enwrapped in the fill tended to stake, which resulted in the increase of the surface roughness of the fill. Moreover, the friction force and the wear depth increased in a small range with the increase of the scan cycles. However, two kinds of abnormal phenomena were observed during experiment. One is the fill peeling off under the action of the shear force. The other is the packing of the nanoparticles happened and the thickness of the wear surface was larger than that of the unworn surface.

关 键 词：PDDA/Au NPs复合分子沉积(MD)膜 柠檬酸钠包覆改性金纳米粒子 摩擦 磨损 

分 类 号：TB383.2[一般工业技术—材料科学与工程]