Synthesis of zwitterionic diblock copolymers without protecting group chemistry

Cong Duan Vo, Steven P. Armes, David P. Randall, Kenichi Sakai, Simon Biggs

    Research output: Contribution to journalArticlepeer-review


    A two-step route was used to prepare a range of zwitterionic diblock copolymers in which both blocks are weak polyelectrolytes. In the first step, low polydispersity diblock copolymers of 2-hydroxypropyl methacrylate (HPMA) with either 2-(diethylamino)ethyl methacrylate (DEA) or 2-(diisopropylamino) ethyl methacrylate (DPA) were prepared by atom transfer radical polymerization in protic media under mild conditions in a convenient one-pot synthesis. Block copolymers with varying compositions were prepared by adjusting the comonomer/initiator molar ratio. In the second step, the hydroxyl groups of the diblock copolymers were esterified with excess succinic anhydride (SA) to produce the corresponding zwitterionic diblock copolymers, which exhibit complex pH-dependent behavior (isoelectric points and "schizophrenic"-type micellization) in aqueous solution. The electrostatic adsorption of "cationic corona" micelles onto near-monodisperse anionic silica particles was successful at pH 3.5, as evidenced by aqueous electrophoresis, FT-IR studies, thermogravimetric analysis, and scanning electron microscopy. The same "cationic corona" micelles were also adsorbed onto planar mica at pH 3.5. More surprisingly, inverted "anionic corona" micelles prepared from the same diblock copolymer could be adsorbed onto mica at pH 10. Presumably, this latter adsorption arises from relatively weak hydrophobic interactions due to the micelle cores, rather than strong electrostatic interactions due to the micelle corona. Both types of adsorbed micelles could be imaged by in situ atomic force microscopy. © 2007 American Chemical Society.
    Original languageEnglish
    Pages (from-to)157-167
    Number of pages10
    Issue number2
    Publication statusPublished - 23 Jan 2007


    Dive into the research topics of 'Synthesis of zwitterionic diblock copolymers without protecting group chemistry'. Together they form a unique fingerprint.

    Cite this