Encapsulation and release by star-shaped block copolymers as unimolecular nanocontainers


KUL D. , Van Renterghem L. M. , Meier M. A. R. , Strandman S., Tenhu H., YILMAZ Ş. , ...Daha Fazla

JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY, cilt.46, ss.650-660, 2008 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 46 Konu: 2
  • Basım Tarihi: 2008
  • Doi Numarası: 10.1002/pola.22413
  • Dergi Adı: JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
  • Sayfa Sayıları: ss.650-660

Özet

A five-arm star-shaped poly(ethylene oxide) (PEO) with terminal bromide groups was used as a macroinitiator for the atom transfer radical polymerization of tert-butyl acrylate (tBA), resulting in five-arm star-shaped poly(ethylene oxide)-blockpoly(tert-butyl acrylate) block copolymers. The polymerization proceeded in a controlled way using a copper(I)bromide/pentamethyl diethylenetriamine catalytic system in acetonitrile as solvent. The hydrolysis of the tBA blocks of the amphiphilic star-shaped PEO-b-PtBA block copolymer resulted in dihydrophilic star structures. The encapsulation of the star-block copolymers and their release properties in acid environment have been followed by UV-spectroscopy and color changes, using the dye methyl orange as a hydrophilic guest molecule. Characterization of the structures has been done by H-1 NMR, size exclusion chromatography, MALDI-TOF, and differential scanning calorimetry. (C) 2007 Wiley Periodicals, Inc.