title: Complexes of polydopamine-modified clay and ferric ions as the framework for pollutant-absorbing supramolecular hydrogels.
abstract: Clay-based functional hydrogels were facilely prepared via a bioinspired approach. Montmorillonite (clay) was exfoliated into single layers in water and then coated with a thin layer of polydopamine (PDOPA) via in situ polymerization of dopamine under basic aqueous conditions. When a small amount of ferric salt was added into aqueous suspensions of the polydopamine-coated clay (D-clay), D-clay and Fe(3+) ions could rapidly self-assemble into three-dimensional networks through the formation of coordination bonds. Consequently, supramolecular hydrogels were formed at very low D-clay contents. Rheological measurements show that the D-clay/Fe(3+) hydrogels exhibit fairly elastic response in low stain range, and have self-healing capability upon removal of applied large stress. More importantly, the hydrogels can be used as adsorbents to effectively remove Rhodamine 6G (Rh6G), an organic pollutant, from water. UV-vis absorption spectra of the Rh6G-loaded hydrogels show bands related to π-π stacking interactions between the aromatic moieties of PDOPA and Rh6G, confirming the formation of PDOPA/Rh6G complex on the surface of D-clay.
authors.affiliation: School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798.
authors.forename: Shu
authors.initials: S
authors.lastname: Huang
authors.forename: Liping
authors.initials: L
authors.lastname: Yang
authors.forename: Ming
authors.initials: M
authors.lastname: Liu
authors.forename: Si Lei
authors.initials: SL
authors.lastname: Phua
authors.forename: Wu Aik
authors.initials: WA
authors.lastname: Yee
authors.forename: Wanshuang
authors.initials: W
authors.lastname: Liu
authors.forename: Rui
authors.initials: R
authors.lastname: Zhou
authors.forename: Xuehong
authors.initials: X
authors.lastname: Lu