Naresh Kumar Nitturi, Yap Seong Ling, Bt Samsudin Farah Nadia Dayana, Khan Muhammad Zubair, Pattela Srinivasa Rama Sreekanth
Plasma Research Laboratory, Department of Physics, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia.
Department of Physics, Federal Urdu University of Arts, Science & Technology, 45320 Islamabad, Pakistan.
Polymers (Basel). 2016 Aug 11;8(8):295. doi: 10.3390/polym8080295.
Ultra-high molecular weight polyethylene (UHMWPE) is widely used in artificial joints in the replacement of knee, hip and shoulder that has been impaired as a result of arthritis or other degenerative joint diseases. The UHMWPE made plastic cup is placed in the joint socket in contact with a metal or ceramic ball affixed to a metal stem. Effective reinforcement of multi-walled carbon nanotubes (MWCNTs) in UHMWPE results in improved mechanical and tribological properties. The hydrophobic nature of the nanocomposites surface results in lesser contact with biological fluids during the physiological interaction. In this project, we investigate the UHMWPE/MWCNTs nanocomposites reinforced with MWCNTs at different concentrations. The samples were treated with cold argon plasma at different exposure times. The water contact angles for 60 min plasma-treated nanocomposites with 0.0, 0.5, 1.0, 1.5, and 2.0 wt % MWCNTs were found to be 55.65°, 52.51°, 48.01°, 43.72°, and 37.18° respectively. Increasing the treatment time of nanocomposites has shown transformation from a hydrophobic to a hydrophilic nature due to carboxyl groups being bonded on the surface for treated nanocomposites. Wear analysis was performed under dry, and also under biological lubrication, conditions of all treated samples. The wear factor of untreated pure UHMWPE sample was reduced by 68% and 80%, under dry and lubricated conditions, respectively, as compared to 2 wt % 60 min-treated sample. The kinetic friction co-efficient was also noted under both conditions. The hardness of nanocomposites increased with both MWCNTs loading and plasma treatment time. Similarly, the surface roughness of the nanocomposites was reduced.
超高分子量聚乙烯（UHMWPE）广泛应用于人工关节，用于置换因关节炎或其他退行性关节疾病而受损的膝盖、髋关节和肩关节。由UHMWPE制成的塑料杯放置在关节窝中，与固定在金属柄上的金属或陶瓷球接触。在UHMWPE中有效增强多壁碳纳米管（MWCNTs）可改善其机械性能和摩擦学性能。纳米复合材料表面的疏水性导致其在生理相互作用过程中与生物流体的接触较少。在本项目中，我们研究了不同浓度MWCNTs增强的UHMWPE/MWCNTs纳米复合材料。样品在不同暴露时间下用冷氩等离子体处理。发现经60分钟等离子体处理的含0.0、0.5、1.0、1.5和2.0 wt%MWCNTs的纳米复合材料的水接触角分别为55.65°、52.51°、48.01°、43.72°和37.18°。由于处理后的纳米复合材料表面结合了羧基，增加纳米复合材料的处理时间已显示出从疏水性向亲水性的转变。对所有处理过的样品在干燥和生物润滑条件下进行了磨损分析。与2 wt%60分钟处理的样品相比，未处理的纯UHMWPE样品在干燥和润滑条件下的磨损因子分别降低了68%和80%。在两种条件下也记录了动摩擦系数。纳米复合材料的硬度随MWCNTs负载量和等离子体处理时间的增加而增加。同样，纳米复合材料的表面粗糙度降低。
