title: Excellent anti-corrosive pretreatment layer on iron substrate based on three-dimensional porous phytic acid/silane hybrid.
abstract: A novel, highly effective and environmentally friendly film-forming material, phytic acid (PA)/silane (denoted as PAS) hybrid with a three-dimensional (3D) network structure, was prepared through a condensation reaction of PA with methyltrihydroxysilane generated from the hydrolysis of methyltriethoxysilane (MTES). Two kinds of PAS-based pretreatment layers, namely NaBrO3-free and NaBrO3-doped PAS layers, were fabricated on iron substrates using the dip-coating method. SEM and AFM observations showed that the as-fabricated PAS-based layers possessed a 3D porous microstructure at the nanoscale and a rough surface morphology. X-ray photoelectron spectroscopic (XPS) and attenuated total reflection infrared (ATR-IR) spectroscopic characterization demonstrated that the above PAS layers bound to the iron surface via the -P-O- bond. Moreover, analyses of steady-state polarization curves and electrochemical impedance spectroscopic (EIS) data indicated that the corrosion rates of the iron substrates decreased considerably in the presence of the two PAS-based pretreatment layers. In particular, the NaBrO3-dosed PAS layer displayed the better corrosion resistance ability as well as maintaining the original microstructure and surface morphology. The PAS-based pretreatment layers are expected to act as substitutes for chromate and phosphate conversion layers and will find widespread application in the surface pretreatment of iron and steel materials due to the advantages of being environmentally friendly, the rapid film-forming process, and, especially, the nanoporous microstructure and rough surface morphology.
authors.affiliation: Key Laboratory of Colloid and Interface Chemistry of State Education Ministry, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China. hyma@sdu.edu.cn.
authors.forename: Xiang
authors.initials: X
authors.lastname: Gao
authors.affiliation: Key Laboratory of Colloid and Interface Chemistry of State Education Ministry, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China. hyma@sdu.edu.cn.
authors.forename: Ke
authors.initials: K
authors.lastname: Lu
authors.affiliation: Key Laboratory of Colloid and Interface Chemistry of State Education Ministry, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China. hyma@sdu.edu.cn.
authors.forename: Lei
authors.initials: L
authors.lastname: Xu
authors.affiliation: Key Laboratory of Colloid and Interface Chemistry of State Education Ministry, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China. hyma@sdu.edu.cn.
authors.forename: Hua
authors.initials: H
authors.lastname: Xu
authors.affiliation: Key Laboratory for Special Functional Aggregate Materials of State Education Ministry, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China.
authors.forename: Haifeng
authors.initials: H
authors.lastname: Lu
authors.affiliation: Applied Physics Department, Shandong Agricultural University, Taian, 271018, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Gao
authors.affiliation: National Engineering Research Center for Colloidal Materials, Shandong University, Jinan 250100, China.
authors.forename: Shifeng
authors.initials: S
authors.lastname: Hou
authors.affiliation: Key Laboratory of Colloid and Interface Chemistry of State Education Ministry, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China. hyma@sdu.edu.cn.
authors.forename: Houyi
authors.initials: H
authors.lastname: Ma