title: Stabilized mixed micelles with a temperature-responsive core and a functional shell.
abstract: Formation and stabilization of multiresponsive micelles with a mixed poly(ethylene oxide)/polyelectrolyte shell and a temperature-responsive poly(propylene oxide) core were studied. Various poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) (PEO-PPO-PEO) triblock copolymers were mixed with poly(acrylic acid)-block-poly(propylene oxide)-block-poly(acrylic acid) (PAA-PPO-PAA) or poly(dimethylaminoethyl methacrylate)-block-poly(propylene oxide)-block-poly(dimethylaminoethyl methacrylate) (PDMAEMA-PPO-PDMAEMA) triblock copolymers. The micelles formed by binary mixtures of well-defined compositions at a specific pH were additionally stabilized by loading with pentaerythritol tetraacrylate (PETA), that was polymerized and cross-linked "in situ" with UV assistance. Depending on both the composition of the copolymers and the experimental conditions, either spherical or wormlike "stabilized polymeric micelles with a mixed shell" (SPMMS) were observed by dynamic light scattering (DLS) and transmission electron microscopy (TEM). The SPMMS that contained PAA blocks in the shell were pH-sensitive, such that a reversible transition from well-dispersed SPMMS to precipitate could be promoted. In contrast, the SPMMS with a PEO/PDMAEMA mixed shell remained well-dispersed in the 2-11 pH range. Finally, SPMMS were successfully exploited as templates for the preparation of Ag nanoparticles (Ag NPs).
authors.affiliation: Institute of Polymers, Bulgarian Academy of Sciences, Akad. G. Bonchev Street 103A, 1113 Sofia, Bulgaria. ppetrov@polymer.bas.bg
authors.forename: Petar
authors.initials: P
authors.lastname: Petrov
authors.forename: Christo B
authors.initials: CB
authors.lastname: Tsvetanov
authors.forename: Robert
authors.initials: R
authors.lastname: Jérôme
mesh_terms: D000179:Acrylates / Q000737:chemistry; D008027:Light; D008823:Micelles; D046529:Microscopy, Electron, Transmission; D008968:Molecular Conformation; D011092:Polyethylene Glycols / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D011409:Propylene Glycols / Q000737:chemistry*; D012542:Scattering, Radiation; D013499:Surface Properties; D013696:Temperature
chemical_list: D000179:Acrylates; D008823:Micelles; D011108:Polymers; D011409:Propylene Glycols; C012504:polypropylene glycol; D011092:Polyethylene Glycols; C531365:pentaerythritol tetraacrylate