Development of Zn-polyethyleneimine-active metal nanoparticles composite films electrodeposited on steel sheets

2020 Fiscal Year Final Research Report

• Project/Area Number: 18H01753
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 26050:Material processing and microstructure control-related
• Research Institution: Kyushu University
• Principal Investigator: Nakano Hiroaki 九州大学, 工学研究院, 教授 (70325504)
• Co-Investigator(Kenkyū-buntansha): 大上 悟 九州大学, 工学研究院, 助教 (90264085)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 複合電析 / 亜鉛 / 活性金属 / ポリエチレングリコール / ジルコニウム / バナジウム / 電流効率 / 加水分解

Outline of Final Research Achievements

The effects of polyethylene glycol (PEG) addition on the co-deposition of Zr and V oxides and their corrosion resistance, and on the microstructure of the deposits, were investigated. Zr and V contents in the deposits increased with PEG addition. In the presence of PEG, the cathode potential polarized, the rate of hydrogen evolution increased, and the hydrolysis reaction of Zr4+ and VO2+ ions proceeded smoothly, resulting in an increase in the Zr and V content in the deposits. Additionally, the crystal platelets of Zn in the Zn-Zr and the Zn-V oxide films became fine, and the surface coverage of the spongiform Zr and film-like V oxides increased. Furthermore, the corrosion current densities of the Zn-Zr and Zn-V oxide films obtained from the solution with PEG were lower than those from the solution without it. The reduction rate of dissolved oxygen decreased in the films in the presence of PEG, thereby leading to a decrease in the corrosion current density.

Free Research Field

材料電気化学

Academic Significance and Societal Importance of the Research Achievements

ポリエチレングリコール(PEG)と活性金属酸化物のナノ微粒子を均一に分散させた高耐食性複合亜鉛電析膜について多くの知見が得られた。Zn電析時の水の電気分解反応による陰極界面のpH上昇を利用して，活性金属イオンを加水分解させその場で酸化物を形成し，その酸化物にPEGを吸着させ，PEGの陰極面への吸着によりPEGと活性金属酸化物をZn電析膜に共析させた。Zn－Zr，V酸化物電析膜の耐食性は共に，PEGを添加すると溶存酸素の還元反応が減少するため，向上した。本めっき手法は，新しい表面処理プロセス，即ち固形の分散粒子を含まない非懸濁電解液からの複合電析プロセスへの道を拓くものとして期待される。