Study of complex thermosensitive amphiphilic polyoxazolines and their interaction with ionic surfactants. Are hydrophobic, thermosensitive, and hydrophilic moieties equally important?

0427980 - ÚMCH 2015 RIV US eng J - Journal Article
Bogomolova, Anna - Filippov, Sergey K. - Starovoytova, Larisa - Angelov, Borislav - Konarev, P. - Sedláček, Ondřej - Hrubý, Martin - Štěpánek, Petr
Study of complex thermosensitive amphiphilic polyoxazolines and their interaction with ionic surfactants. Are hydrophobic, thermosensitive, and hydrophilic moieties equally important?
Journal of Physical Chemistry B. Roč. 118, č. 18 (2014), s. 4940-4950. ISSN 1520-6106. E-ISSN 1520-5207
R&D Projects: GA ČR GAP205/11/1657; GA MPO FR-TI4/625
Grant - others:AV ČR(CZ) M200501201
Program: M
Institutional support: RVO:61389013
Keywords : poly(2-alkyl-2-oxazoline) * thermosensitivity * ionic surfactant
Subject RIV: CD - Macromolecular Chemistry
Impact factor: 3.302, year: 2014

The temperature-driven self-assembly of nonionic amphiphilic tailor-made triblock copolymers has been studied by DLS, NMR, ITC, and SAXS. The composition of these triblock copolymers is more complex than that of the vast majority of poly(2-alkyl-2-oxazoline)s: a statistical thermoresponsive (iPrOx) and hydrophobic (BuOx) central block with terminal hydrophilic blocks (MeOx). In general, as temperature increases, nanoparticles form in a process starting with single molecules that become loose aggregates and ends with the formation of compact nanoparticles. Here, we first attempt to resolve the effects of each block on nanoparticle formation. It has been proven that the iPrOx/MeOx ratio determines the value of the cloud point temperature, whereas the different BuOx–iPrOx blocks determine the character of the process. Finally, we complete our investigation by presenting the thermodynamic and structural profiles of the complexation between these triblock poly(2-alkyl-2-oxazoline)s and two ionic surfactants. The addition of an ionic surfactant promotes a rearrangement of the polymer molecules and the formation of complexes followed by the appearance of polymer–surfactant hybrid micelles. Analysis of the interaction shows a strong and nonspecific reaction between the polymers and the anionic surfactant sodium dodecyl sulfate and weak but polymer-state-sensitive interactions between the polymer and the cationic surfactant hexadecyltrimethylammonium bromide.
Permanent Link: http://hdl.handle.net/11104/0234082