Charge selective encapsulation by polymeric micelles with cationic,anionic, or zwitterionic cores |
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Authors: | Decheng Wan Ming Jin Hongting Pu Guowei Wang |
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Institution: | 1. Institute of Functional Polymers, School of Materials Science and Engineering, Tongji University, 4800 Cao‐an Road, Shanghai 201804, China;2. Key Laboratory of Advanced Civil Engineering Materials (Tongji University), Ministry of Education, Shanghai 201804, China;3. Key Laboratory of Molecular Engineering of Polymers, Fudan University, Ministry of Education, 220 Handan Road, Shanghai 200433, China |
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Abstract: | Polymeric micelles showing charge selective and pH‐reversible encapsulation are reported. It is found that for a guest mixture of organic cationic–anionic dyes, a unimolecular micelle (PEI@PS) with a polystyrene (PS) as shell and a hyperbranched polyethylenimine (PEI) as core can exclusively entrap the anionic one; and a physical micelle consisting of brush‐like macromolecule (mPS‐PAA) with multi PS‐b‐polyacrylic acid (PAA) as grafts can exclusively entrap the cationic one. A covalent micelle (PEI‐COOH@PS) bearing a zwitterionic core, that is, PEI covalently derived with dense carboxylic acids, can undergo highly pH‐switchable charge selective and pH‐reversible encapsulation. Both PEI@PS and mPS‐PAA can be used for highly charge‐selective separation of ionic dyes but the pH‐reversibility of the encapsulation is relatively limited. In contrast, PEI‐COOH@PS is less effective to differentiate the anionic–cationic dyes but is well recyclable. A physical micelle obtained from the self‐assembly of PEI and mPS‐PAA shows similar property to PEI‐COOH@PS. The combination of these micelles in mixture separation can enhance the recyclability of the micelle and widen the spectrum of mixtures that can be well separated. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 |
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Keywords: | charge selective core‐shell polymers encapsulation host‐guest systems molecular recognition nanocapsule pH‐switch separation |
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