Abstract
Poly(methacrylic acid)-grafted hollow silica vesicles (PMAA-g-hollow silica vesicles) were obtained through a grafting-from approach. PMAA brushes were formed by performing atom-transfer radical polymerisation of sodium methacrylate with an initiator attached to the hollow silica spheres. PMAA-g-hollow silica vesicles were characterised by using TEM, thermogravimetric analysis (TGA) and FTIR spectroscopy. pH-dependent φ potential and 1H NMR spectra of PMAA-g-hollow silica vesicles were measured, and the results indicated that MAA brushes in PMAA-g-hollow silica vesicles had a lower ionisation degree and low solubility in acidic aqueous solution, for example, pH 3.4, but a higher ionisation degree and high solubility when the pH was higher than 7. Also it was demonstrated that calcein blue and fluorescein isothiocyanate (FITC) labelled dextran (Mn: 10 kDa) could be encapsulated in the interiors of the PMAA-g-hollow silica vesicles with a negligible amount in PMAA brushes at pH 2, and pH-triggered release of calcein blue and FITC-labelled dextran from PMAA-g-hollow silica vesicles was observed at pH 7.4.
| Original language | English |
|---|---|
| Pages (from-to) | 2504-2509 |
| Number of pages | 6 |
| Journal | Chemistry - A European Journal |
| Volume | 17 |
| Issue number | 8 |
| DOIs | |
| Publication status | Published - Feb 18 2011 |
| Externally published | Yes |
ASJC Scopus Subject Areas
- Catalysis
- Organic Chemistry
Keywords
- pH responses
- poly(methacrylic acid)
- polymers
- silica
- vesicles