title: A novel smart microsphere with magnetic core and ion-recognizable shell for Pb2+ adsorption and separation.
abstract: Smart core-shell microspheres for selective Pb(2+) adsorption and separation have been developed. Each microsphere is composed of a Pb(2+) recognizable poly(N-isopropylacrylamide-co-benzo-18-crown-6-acrylamide) (PNB) shell and a magnetic Fe3O4 core. The magnetic PNB core-shell microspheres show excellent Pb(2+) adsorption selectivity among the coexisting Cd(2+), Co(2+), Cr(3+), Cu(2+), Ni(2+), Zn(2+), K(+), and Ca(2+) ions by forming stable B18C6Am/Pb(2+) host-guest complexes and exhibit an interesting temperature-dependent Pb(2+) adsorption. The inner independent magnetic Fe3O4 cores enable the Pb(2+)-adsorbed microspheres with a magnetically guided aggregation to be separated from the treated solution using a remotely controlled manner. The isothermal Pb(2+) adsorption result fits well with the Freundlich isotherm. The magnetic PNB core-shell microspheres show very fast adsorption of Pb(2+), and the adsorption process of Pb(2+) onto magnetic PNB core-shell microspheres fits well with the pseudo-second-order model. Moreover, Pb(2+)-adsorbed microspheres can be regenerated by simply increasing the operation temperature and washing with deionized water. The proposed magnetic PNB core-shell microspheres provide a promising candidate for Pb(2+) adsorbents with selectively separable and efficiently reusable abilities.
authors.affiliation: School of Chemical Engineering, ‡State Key Laboratory of Polymer Materials Engineering, and Collaborative Innovation Center for Biomaterials Science and Technology, Sichuan University , Chengdu, Sichuan 610065, People's Republic of China.
authors.forename: Ying-Mei
authors.initials: YM
authors.lastname: Liu
authors.forename: Xiao-Jie
authors.initials: XJ
authors.lastname: Ju
authors.forename: Yan
authors.initials: Y
authors.lastname: Xin
authors.forename: Wei-Chao
authors.initials: WC
authors.lastname: Zheng
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.forename: Jie
authors.initials: J
authors.lastname: Wei
authors.forename: Rui
authors.initials: R
authors.lastname: Xie
authors.forename: Zhuang
authors.initials: Z
authors.lastname: Liu
authors.forename: Liang-Yin
authors.initials: LY
authors.lastname: Chu