title: Bio-inspired fabrication of hierarchical FeOOH nanostructure array films at the air-water interface, their hydrophobicity and application for water treatment.
abstract: Hierarchical FeOOH nanostructure array films constructed by different nanosized building blocks can be synthesized at the air-water interface via a bio-inspired gas-liquid diffusion method. In this approach, poly(acrylic acid) (PAA) as a crystal growth modifier plays a crucial role in mediating the morphology and polymorph of FeOOH crystals. With the increase of PAA concentration, the shape of the building blocks assembling into FeOOH films can be tailored from nanosheets, to rice spikes, then to branched fibers, and finally to nanowires. What is more, a low concentration of PAA will induce the formation of α-FeOOH, while a high one could stabilize FeOOH in the form of the γ-FeOOH phase. After being modified with a thin layer of polydimethylsiloxane (PDMS), the as-prepared FeOOH films exhibited strong hydrophobicity with water contact angles (CA) from 134° to 148° or even superhydrophobicity with a CA of 164° in the sample constructed by nanosheets. When the FeOOH nanostructures were dispersed in water by ultrasound, they displayed quite promising adsorption performance of heavy metal ions for water treatment, where the highest adsorption capacity can reach 77.2 mg·g⁻¹ in the sample constructed by nanowires. This bio-inspired approach may open up the possibilities for the fabrication of other functional nanostructure thin films with unique properties.
authors.affiliation: Hefei National Laboratory for Physical Sciences at Microscale, Department of Chemistry,CAS Key Laboratory of Mechanical Behavior and Design of Materials, the National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230026, P. R. China.
authors.forename: Lei
authors.initials: L
authors.lastname: Liu
authors.forename: Liu-Qing
authors.initials: LQ
authors.lastname: Yang
authors.forename: Hai-Wei
authors.initials: HW
authors.lastname: Liang
authors.forename: Huai-Ping
authors.initials: HP
authors.lastname: Cong
authors.forename: Jun
authors.initials: J
authors.lastname: Jiang
authors.forename: Shu-Hong
authors.initials: SH
authors.lastname: Yu
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D000388:Air; D032701:Biomimetics / Q000379:methods*; D004058:Diffusion; D005290:Ferric Compounds / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D019216:Metals, Heavy / Q000737:chemistry / Q000302:isolation & purification; D049329:Nanostructures / Q000737:chemistry*; D036103:Nanotechnology; D014867:Water / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*
chemical_list: D000180:Acrylic Resins; D005290:Ferric Compounds; D019216:Metals, Heavy; D014867:Water; C006903:carbopol 940