Charged microcapsules for controlled release of hydrophobic actives. Part III: The effect of polyelectrolyte brush- and multilayers on sustained release
Journal article, 2013

Poly(methyl methacrylate) microspheres have been prepared by the internal phase separation method using either of the three conventional dispersants poly(vinyl alcohol) (PVA), poly(methacrylic acid) (PMAA), or the amphiphilic block copolymer poly(methyl methacrylate)-block-poly(sodium methacrylate). The block copolymer based microsphere, which has a polyelectrolyte brush on the surface, was surface modified with up to two poly(diallyldimethylammonium chloride)-poly(sodium methacrylate) bilayers. The microspheres were loaded with the hydrophobic dye 2-(4-(2-chloro-4-nitrophenylazo)-N-ethylphenylamino)ethanol (Disperse Red 13) and its release from aqueous dispersions of microspheres with the different surface compositions was measured by spectrophotometry. The burst fraction, burst rate and the diffusion constant were determined from a model combining burst and diffusive release. Out of the three dispersants, the block copolymer gave the slowest release of the dye, with respect to both burst release and diffusive release. A very pronounced further reduction of the diffusion constant was obtained by applying polyelectrolyte multilayers on top of the microspheres. However, the diffusion constant was very weakly dependent on further polyelectrolyte adsorption and one polyelectrolyte bilayer appeared to suffice.

Author

Markus Andersson Trojer

SuMo Biomaterials

Chalmers, Chemical and Biological Engineering, Applied Surface Chemistry

Helena Andersson

Chalmers, Chemical and Biological Engineering, Applied Surface Chemistry

Ye Li

Chalmers, Chemical and Biological Engineering, Applied Surface Chemistry

Jonatan Bergek

Chalmers, Chemical and Biological Engineering, Applied Surface Chemistry

Krister Holmberg

Chalmers, Chemical and Biological Engineering, Applied Surface Chemistry

Magnus Nydén

Chalmers, Chemical and Biological Engineering, Applied Surface Chemistry

SuMo Biomaterials

Lars Nordstierna

Chalmers, Chemical and Biological Engineering, Applied Surface Chemistry

Physical Chemistry Chemical Physics

1463-9076 (ISSN) 1463-9084 (eISSN)

Vol. 15 17 6153-6165

Subject Categories

Physical Chemistry

Areas of Advance

Materials Science

DOI

10.1039/c3cp50417d

More information

Created

10/8/2017