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Differences in self‐assembly features of thermoresponsive anionic triblock copolymers synthesized via one‐pot or two‐pot by atom transfer radical polymerization

Motlaq, Vahid F. ; Momtazi, Leva ; Zhu, Kaizheng ; Knudsen, Kenneth D. ; Nyström, Bo

Journal of polymer science. Part B, Polymer physics, 2019-05, Vol.57 (9), p.524-534 [Periódico revisado por pares]

Hoboken, USA: John Wiley & Sons, Inc

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  • Título:
    Differences in self‐assembly features of thermoresponsive anionic triblock copolymers synthesized via one‐pot or two‐pot by atom transfer radical polymerization
  • Autor: Motlaq, Vahid F. ; Momtazi, Leva ; Zhu, Kaizheng ; Knudsen, Kenneth D. ; Nyström, Bo
  • Assuntos: Acrylamide ; Aqueous solutions ; Assembly ; Block copolymers ; charged triblock copolymer ; Chemical synthesis ; dynamic light scattering (DLS) ; High temperature ; Micelles ; Neutron scattering ; Polyethylene glycol ; Polymerization ; self‐assembling process ; small‐angle neutron scattering (SANS) ; Temperature ; zeta potential ; “one‐pot” and “two‐pot” by atom transfer radical polymerization (ATRP)
  • É parte de: Journal of polymer science. Part B, Polymer physics, 2019-05, Vol.57 (9), p.524-534
  • Notas: EC/FP7/290251
  • Descrição: ABSTRACT The self‐assembly process in aqueous solutions of the methoxyl‐poly(ethylene glycol)‐block‐poly(2‐acrylamido‐2‐methyl‐1‐propanesulfonic sodium)‐block‐poly(N‐isopropyl acrylamide) (PNIPAAM) triblock copolymer, synthesized via two different atomic transfer radical polymerization methods, namely “one‐pot” (P3‐sample) and “two‐pot” (P2‐sample), was studied by various experimental techniques. The “one‐pot” procedure leads to a copolymer (P3) where the PNIPAAM block is contaminated with a minor quantity of 2‐acrylamido‐2‐methyl‐1‐propane sulfonate (AMPS) residuals and this sample does not form micelles over the considered temperature region, but unimers and temperature‐induced aggregates coexist in the presence of a small amount of salt. The P2 polymer forms micelles and intermicellar structures, but the former moieties disappear at high temperatures, whereas the latter species contract with increasing temperature. Small‐angle neutron scattering results revealed correlation peaks, both for P3 and P2, and no micelle formation for P3, but a pronounced upturn of the scattered intensity at low wavevector values at elevated temperatures for the P2 copolymer. The findings from this study clearly show that the spurious AMPS residuals have a drastic influence on the self‐assembly and micelle formation of the triblock copolymer. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019, 57, 524–534 Thermosensitive anionic triblock copolymers of methoxyl‐poly(ethylene glycol)‐block‐poly(2‐acrylamido‐2‐methyl‐1‐propanesulfonic sodium)‐block‐poly(N‐isopropyl acrylamide) (PNIPAAM) were synthesized via two different atomic transfer radical polymerization methods, namely “one‐pot” and “two‐pot.” The “one‐pot” procedure led to a copolymer where the PNIPAAM block is contaminated with a minor quantity of 2‐acrylamido‐2‐methyl‐1‐propane sulfonate (AMPS) residuals, whereas no AMPS contamination of the PNIPAAM block occurred in the “two‐pot” procedure. The latter method gave rise to micelles and intermicellar structures in aqueous solution at elevated temperatures, whereas the “one‐pot” procedure only produced stabilized unimers in all conditions.
  • Editor: Hoboken, USA: John Wiley & Sons, Inc
  • Idioma: Inglês;Norueguês
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