Počet záznamů: 1

pH-triggered reversible sol–gel transition in aqueous solutions of amphiphilic gradient copolymers

  1. 1.
    0366060 - UMCH-V 2012 RIV GB eng J - Článek v odborném periodiku
    Borisova, O. - Billon, L. - Zaremski, M. - Grassl, B. - Bakaeva, Zulfiya - Lapp, A. - Štěpánek, Petr - Borisov, O.
    pH-triggered reversible sol–gel transition in aqueous solutions of amphiphilic gradient copolymers.
    Soft Matter. Roč. 7, č. 22 (2011), s. 10824-10833 ISSN 1744-683X
    Grant CEP: GA ČR GAP208/10/1600
    Výzkumný záměr: CEZ:AV0Z40500505
    Klíčová slova: small angle neutron scattering * triblock copolymer * self-organized structure
    Kód oboru RIV: CF - Fyzikální chemie a teoretická chemie
    Impakt faktor: 4.390, rok: 2011

    We demonstrate the possibility of reversible pH-controlled sol–gel transition in aqueous solution of associating amphiphilic triblock copolymer poly(styrene-grad-acrylic acid)-b-poly(acrylic acid)-b-poly(styrene-grad-acrylic acid), synthesized via nitroxide-mediated radical copolymerization. The presence of pH-sensitive co-monomer units of the acrylic acid in the terminal blocks ensures the dynamic nature of the styrene-rich hydrophobic nano-domains which are formed at low pH. At small polymer concentrations the association triggered by lowering the pH gives rise to flower-like micelles stabilized by partially ionized PAA coronae. The pH-controlled association was monitored by DLS-titration and manifested in the evolution of a correlation peak in the SANS spectra. Above the micelle overlap concentration a decrease in pH provokes macroscopic gelation where the styrene-reach domains perform as pH-controllable cross-links in the transient network.
    Trvalý link: http://hdl.handle.net/11104/0201153