title: Water-soluble interpolyelectrolyte complexes of polyisobutylene-block-poly(methacrylic acid) micelles: formation and properties.
abstract: We report on interpolyelectrolyte complexes (IPECs) formed by micelles of ionic amphiphilic diblock copolymers with polyisobutylene (PIB) and poly(sodium methacrylate) (PMANa) blocks interacting with quaternized poly(4-vinylpyridine) (P4VPQ). The interpolyelectrolyte complexation was followed by turbidimetry and small angle neutron scattering (SANS). The data obtained by means of a combination of SANS, dynamic light scattering (DLS), and cryogenic transmission electron microscopy (cryo-TEM) provide evidence on the core-shell-corona structure of the complex species with the shell assembled from fragments of electrostatically bound PMANa and quaternized P4VPQ fragments, original PIBx-b-PMAAy micelles apparently playing a lyophilizing part. The complex formation is followed by potentiometric titration as well. This process is initially kinetically controlled. In the second step larger aggregates rearrange in favor of smaller complexes with core-shell-corona structure, which are thermodynamically more stable. An increase in ionic strength of the solution results in dissociation of the complex species as proven by SANS and analytical ultracentrifugation (AUC). This process begins at the certain threshold ionic strength and proceeds via a salt-induced gradual release of chains of the cationic polyectrolyte from the complex species.
authors.affiliation: Makromolekulare Chemie II, Universitä t Bayreuth, D-95440 Bayreuth, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Burkhardt
authors.forename: Markus
authors.initials: M
authors.lastname: Ruppel
authors.forename: Sandrine
authors.initials: S
authors.lastname: Tea
authors.forename: Markus
authors.initials: M
authors.lastname: Drechsler
authors.forename: Ralf
authors.initials: R
authors.lastname: Schweins
authors.forename: Dmitry V
authors.initials: DV
authors.lastname: Pergushov
authors.forename: Michael
authors.initials: M
authors.lastname: Gradzielski
authors.forename: Alexander B
authors.initials: AB
authors.lastname: Zezin
authors.forename: Axel H E
authors.initials: AH
authors.lastname: Müller
mesh_terms: D000475:Alkenes / Q000737:chemistry*; D004573:Electrolytes / Q000737:chemistry*; D046911:Macromolecular Substances / Q000737:chemistry; D008689:Methacrylates / Q000737:chemistry*; D008823:Micelles; D011108:Polymers / Q000737:chemistry*; D012995:Solubility; D014867:Water / Q000737:chemistry*
chemical_list: D000475:Alkenes; D004573:Electrolytes; D046911:Macromolecular Substances; D008689:Methacrylates; D008823:Micelles; D011108:Polymers; C529071:polyisobutylene-block-poly(methacrylic acid); D014867:Water; C008384:methacrylic acid; C008176:isobutylene