title: An investigation on the biotribocorrosion behaviour of CoCrMo alloy grafted with polyelectrolyte brush.
abstract: Surface grafting of polyelectrolyte brush, such as 3-sulfopropyl methacrylate potassium salt (SPMK), on hip implant materials has been reported to reduce the wear of the orthopaedic bearing surface. However, the biotribocorrosion behaviour of the SPMK brush has not been taken into consideration in previous research. In the present study, SPMK was grafted on Co28Cr6Mo alloy through photo-induced polymerization, and the biotribocorrosion behaviour was investigated by a series of frictional-electrochemical tests using a universal materials tester combined with an electrochemical measurement (three-electrode) system. Co28Cr6Mo disk and polyethylene (PE) pin were used as the contact pair, and the lubricants were 0.9% saline solution (NaCl) and 0.9% saline solution coupled with 25% bovine serum albumin (BSA). The results showed that SPMK was successfully grafted on Co28Cr6Mo alloy, which was confirmed by the comparison of Raman spectroscopy and static contact angle of the samples before and after surface modification. The greatly reduced electrochemical parameters such as corrosion current and pitting potential indicated that the corrosion rate of Co28Cr6Mo alloy was significantly reduced following SPMK grafting. Additionally, the frictional-electrochemical coupled measurement performed under reciprocating sliding demonstrated that the lowest corrosion current was obtained for the SPMK-grafted Co28Cr6Mo disk, with 0.9% NaCl coupled with 25% BSA as the electrolyte. It is indicated from the present study that SPMK polyelectrolyte brush can greatly improve the anti-biotribocorrosion properties of Co28Cr6Mo alloy, and thus has potential application on surface modification of hip implant materials.
authors.affiliation: State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China.
authors.forename: Hong-Yu
authors.initials: HY
authors.lastname: Zhang
authors.affiliation: Corrosion and Protection Center, Beijing University of Science and Technology, Beijing 100083, China.
authors.forename: Yu-Jiao
authors.initials: YJ
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China.
authors.forename: Xiang-Yu
authors.initials: XY
authors.lastname: Hu
authors.affiliation: State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China.
authors.forename: Yan-Fang
authors.initials: YF
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China.
authors.forename: Yu-Long
authors.initials: YL
authors.lastname: Sun
authors.affiliation: Dental Materials Laboratory, National Engineering Laboratory for Digital and Material Technology of Stomatology, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors.forename: Jian-Min
authors.initials: JM
authors.lastname: Han
authors.affiliation: Corrosion and Protection Center, Beijing University of Science and Technology, Beijing 100083, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Yan
authors.affiliation: State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Zhou
mesh_terms: D003343:Corrosion; D004573:Electrolytes; D019544:Equipment Failure Analysis; D017276:Friction; D006622:Hip Prosthesis; D008153:Lubrication; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry*; D020959:Polyethylene / Q000737:chemistry*; D011474:Prosthesis Design; D013499:Surface Properties; D014800:Vitallium / Q000737:chemistry*
chemical_list: C529206:3-sulfopropyl methacrylate; D004573:Electrolytes; D008689:Methacrylates; D014800:Vitallium; D020959:Polyethylene
keywords: Biotribocorrosion; biotribology; hip implant; polyelectrolyte brush; surface grafting