title: An efficient approach to obtaining water-compatible and stimuli-responsive molecularly imprinted polymers by the facile surface-grafting of functional polymer brushes via RAFT polymerization.
abstract: A new and efficient approach to obtaining molecularly imprinted polymers (MIPs) with both pure water-compatible (i.e., applicable in the pure aqueous environments) and stimuli-responsive binding properties is described, whose proof-of-principle is demonstrated by the facile modification of the preformed MIP microspheres via surface-initiated reversible addition-fragmentation chain transfer (RAFT) polymerization of N-isopropylacrylamide (NIPAAm). The presence of poly(NIPAAm) (PNIPAAm) brushes on the obtained MIP microspheres was confirmed by FT-IR as well as the water dispersion and static contact angle experiments, and some quantitative information including the molecular weights and polydispersities of the grafted polymer brushes, the thickness of the polymer brush layers, and their grafting densities was provided. In addition, the binding properties of the ungrafted and grafted MIPs/NIPs in both methanol/water (4/1, v/v) and pure water solutions were also investigated. The introduction of PNIPAAm brushes onto the MIP microspheres has proven to significantly improve their surface hydrophilicity and impart stimuli-responsive properties to them, leading to their pure water-compatible and thermo-responsive binding properties. The application of the facile surface-grafting approach, together with the versatility of RAFT polymerization and the availability of many different functional monomers, makes the present methodology a general and promising way to prepare water-compatible and stimuli-responsive MIPs for a wide range of templates.
authors.affiliation: Key Laboratory of Functional Polymer Materials, Ministry of Education, Department of Chemistry, Nankai University, Weijin Road 94, Tianjin 300071, PR China.
authors.forename: Guoqing
authors.initials: G
authors.lastname: Pan
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.forename: Xianzhi
authors.initials: X
authors.lastname: Guo
authors.forename: Chenxi
authors.initials: C
authors.lastname: Li
authors.forename: Huiqi
authors.initials: H
authors.lastname: Zhang
mesh_terms: D000178:Acrylamides / Q000138:chemical synthesis / Q000737:chemistry; D000180:Acrylic Resins; D001667:Binding, Competitive; D057927:Hydrophobic and Hydrophilic Interactions; D000432:Methanol / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D054802:Molecular Imprinting / Q000379:methods*; D058105:Polymerization; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D013816:Thermodynamics; D014867:Water / Q000737:chemistry
chemical_list: D000178:Acrylamides; D000180:Acrylic Resins; D011108:Polymers; D014867:Water; C052970:poly-N-isopropylacrylamide; D000432:Methanol