title: Adhesive strength of medical polymer on anodic oxide nanostructures fabricated on biomedical β-type titanium alloy.
abstract: Anodic oxide nanostructures (nanopores and nanotubes) were fabricated on a biomedical β-type titanium alloy, Ti-29Nb-13Ta-4.6Zr alloy (TNTZ), by anodization in order to improve the adhesive strength of a medical polymer, segmented polyurethane (SPU), to TNTZ. TNTZ was anodized in 1.0M H3PO4 solution with 0.5 mass% NaF using a direct-current power supply at a voltage of 20V. A nanoporous structure is formed on TNTZ in the first stage of anodization, and the formation of a nanotube structure occurs subsequently beneath the nanoporous structure. The nanostructures formed on TNTZ by anodization for less than 3,600s exhibit higher adhesive strengths than those formed at longer anodization times. The adhesive strength of the SPU coating on the nanoporous structure formed on top of TNTZ by anodization for 1,200s improves by 144% compared to that of the SPU coating on as-polished TNTZ with a mirror surface. The adhesive strength of the SPU coating on the nanotube structure formed on TNTZ by anodization for 3,600s increases by 50%. These improvements in the adhesive strength of SPU are the result of an anchor effect introduced by the nanostructures formed by anodization. Fracture occurs at the interface of the nanoporous structure and the SPU coating layer. In contrast, in the case that SPU coating has been performed on the nanotube structure, fracture occurs inside the nanotubes.
authors.affiliation: Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan. Electronic address: hieda@imr.tohoku.ac.jp.
authors.forename: Junko
authors.initials: J
authors.lastname: Hieda
authors.affiliation: Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan.
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Niinomi
authors.affiliation: Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Nakai
authors.affiliation: Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Cho
authors.affiliation: Department of Materials Science, Graduate School of Engineering, Tohoku University, 6-6-02 Aza Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan.
authors.forename: Tomoyoshi
authors.initials: T
authors.lastname: Mohri
authors.affiliation: Department of Metallic Materials, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, 2-3-10 Kanda-surugadai, Chiyoda-ku, Tokyo 101-0062, Japan.
authors.forename: Takao
authors.initials: T
authors.lastname: Hanawa
mesh_terms: D000269:Adhesives / Q000737:chemistry*; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D004560:Electricity; D004566:Electrodes; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D009556:Niobium / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry*; D056951:Photoelectron Spectroscopy; D011108:Polymers / Q000737:chemistry*; D011140:Polyurethanes / Q000737:chemistry; D013635:Tantalum / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*; D014961:X-Ray Diffraction; D015040:Zirconium / Q000737:chemistry*
chemical_list: D000269:Adhesives; D020099:Coated Materials, Biocompatible; D010087:Oxides; D011108:Polymers; D011140:Polyurethanes; C481486:Ti-29Nb-13Ta-4.6Zr alloy; D009556:Niobium; D013635:Tantalum; D015040:Zirconium; D014025:Titanium
keywords: Adhesive strength; Anodization; Biomedical polymer; Nanopores; Nanotubes; β-Type titanium alloy