title: Metal-Free Photoinduced Electron Transfer-Atom Transfer Radical Polymerization Integrated with Bioinspired Polydopamine Chemistry as a Green Strategy for Surface Engineering of Magnetic Nanoparticles.
abstract: Developing green and efficient technologies for surface modification of magnetic nanoparticles (MNPs) is of crucial importance for their biomedical and environmental applications. This study reports, for the first time, a novel strategy by integrating metal-free photoinduced electron transfer-atom transfer radical polymerization (PET-ATRP) with the bioinspired polydopamine (PDA) chemistry for controlled architecture of functional polymer brushes from MNPs. Conformal PDA encapsulation layers were initially generated on the surfaces of MNPs, which served as the protective shells while providing an ideal platform for tethering 2-bromo-2-phenylacetic acid (BPA), a highly efficient initiator. Metal-free PET-ATRP technique was then employed for controlled architecture of poly(glycidyl methacrylate) (PGMA) brushes from the core-shell MNPs by using diverse organic dyes as photoredox catalysts. Impacts of light sources (including UV and visible lights), photoredox catalysts, and polymerization time on the composition and morphology of the PGMA brushes were investigated. Moreover, the versatility of the PGMA-functionalized core-shell MNPs was demonstrated by covalent attachment of ethylenediamine (EDA), a model functional molecule, which afforded the MNPs with improved hydrophilicity, dispersibility, and superior binding ability to uranyl ions. The green methodology by integrating metal-free PET-ATRP with facile PDA chemistry would provide better opportunities for surface modification of MNPs and miscellaneous nanomaterials for biomedical and electronic applications.
authors.forename: Yang
authors.initials: Y
authors.lastname: Yang
authors.forename: Xuegang
authors.initials: X
authors.lastname: Liu
authors.forename: Gang
authors.identifier: http://orcid.org/0000-0002-7066-940X
authors.initials: G
authors.lastname: Ye
authors.forename: Shan
authors.initials: S
authors.lastname: Zhu
authors.forename: Zhe
authors.initials: Z
authors.lastname: Wang
authors.forename: Xiaomei
authors.initials: X
authors.lastname: Huo
authors.affiliation: Department of Chemistry, Carnegie Mellon University , 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States.
authors.forename: Krzysztof
authors.identifier: http://orcid.org/0000-0003-1960-3402
authors.initials: K
authors.lastname: Matyjaszewski
authors.forename: Yuexiang
authors.identifier: http://orcid.org/0000-0003-2755-7733
authors.initials: Y
authors.lastname: Lu
authors.forename: Jing
authors.initials: J
authors.lastname: Chen
keywords: core−shell structure; magnetic nanoparticles; photoinduced atom transfer radical polymerization; polydopamine; surface-initiated polymerization