Water-dispersible silica-polyelectrolyte nanocomposites prepared via acid-triggered polycondensation of silicic acid and directed by polycations.

Philip Overton, Elena Danilovtseva, Erno Karjalainen, Mikko Karesoja, Vadim Annenkov, Heikki Tenhu, Vladimir Aseyev (Corresponding Author)

Research output: Contribution to journalArticleScientificpeer-review

3 Citations (Scopus)

Abstract

The present work describes the acid-triggered condensation of silicic acid, Si(OH)4, as directed by selected polycations in aq. soln. in the pH range of 6.5-8.0 at room temp., without the use of addnl. solvents or surfactants. This process resulted in the formation of silica-polyelectrolyte (S-PE) nanocomposites in the form of ppt. or water-dispersible particles. The mean hydrodynamic diam. (dh) of size distributions of the prepd. water-dispersible S-PE composites is presented as a function of the soln. pH at which the composite formation was achieved. Poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) and block copolymers of DMAEMA and oligo(ethylene glycol) Me ether methacrylate (OEGMA) were used as weak polyelectrolytes in S-PE composite formation. The activity of the strong polyelectrolytes poly(methacryloxyethyl trimethylammonium iodide) (PMOTAI) and PMOTAI-b-POEGMA in S-PE formation was also examd. The effect of polyelectrolyte strength and the OEGMA block on the formation of the S-PE composites was assessed with respect to the S-PE composites prepd. using the PDMAEMA homopolymer. In the presence of the PDMAEMA60 homopolymer (Mw = 9400 g/mol), the size of the dispersible S-PE composites increases with soln. pH in the range pH 6.6-8.1, from dh = 30 nm to dh = 800 nm. S-PDMAEMA60 prepd. at pH 7.8 contained 66% silica by mass (TGA). The increase in dispersible S-PE particle size was diminished when directed by PDMAEMA300 (Mw = 47,000 g/mol), reaching a max. of dh = 75 nm. S-PE composites formed using PDMAEMA-b-POEGMA remain in the range dh = 20-30 nm across this same pH regime. Pptd. S-PE composites were obtained as spheres of up to 200 nm in diam. (SEM) and up to 65% mass content of silica (TGA). The conditions of pH for the prepn. of dispersible and ppt. S-PE nanocomposites, as directed by the five selected polyelectrolytes PDMAEMA60, PDMAEMA300, PMOTAI60, PDMAEMA60-b-POEGMA38 and PMOTAI60-b-POEGMA38 was summarized.
Original languageEnglish
Article number96
Number of pages19
JournalPolymers
Volume8
Issue number3
DOIs
Publication statusPublished - 2016
MoE publication typeA1 Journal article-refereed

Keywords

  • Polyelectrolytes (cationic
  • water-dispersible silica-polyelectrolyte nanocomposites prepd. via acid-triggered polycondensation of silicic acid and directed by polycations)
  • Polyoxyalkylenes Role: PRP (Properties)
  • SPN (Synthetic preparation)
  • PREP (Preparation) (poly((dimethylamino)ethyl methacrylate)-
  • diblock
  • Colloids
  • Hydrodynamic radius
  • Nanocomposites
  • Nanoscale particle size
  • Polymer morphology
  • RAFT polymerization
  • Zeta potential (water-dispersible silica-polyelectrolyte nanocomposites prepd. via acid-triggered polycondensation of silicic acid and directed by polycations)
  • silica
  • polyelectrolyte
  • nanocomposite
  • hydrodynamic
  • diam
  • property

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