Compositional engineering of polyelectrolyte blend capsules

Heng Pho Yap, John F. Quinn, Angus P.R. Johnston, Frank Caruso

Research output: Contribution to journalArticleResearchpeer-review

11 Citations (Scopus)


This study demonstrates the feasibility of using weak-strong polyelectrolyte (PE) blend systems for controlling the composition and thickness of core-shell particles and PE blend capsules. PE blend capsules were prepared from silica sphere templates via the stepwise adsorption of poly(allylamine hydrochloride) at pH 7.5, in alternation with a varying composition of weak-strong blended PE solutions of poly(acrylic acid) (PAA) and poly(styrene sulfonate) (PSS) at pH 3.5, followed by removal of the silica particles. Confocal laser scanning microscopy was used to confirm that the particle coatings contain all three polymers, and the relative amount of each component was determined by using flow cytometry. Transmission electron microscopy images show that stable PE blend capsules are prepared, in which PSS adds structural integrity. Investigation of the thickness of the capsules via atomic force microscopy indicates that thicker films are obtained when the proportion of PAA in the blend adsorption solution increases. A thickness of ∼12 nm per bilayer is observed for 10% PAA blends, and this increases to ∼20 nm per bilayer for 90% PAA blends. The addition of salt in the adsorption solution also results in thicker multilayers. Blend capsules are expected to find application in the therapeutic and diagnostic fields.

Original languageEnglish
Pages (from-to)7581-7589
Number of pages9
Issue number21
Publication statusPublished - 16 Oct 2007
Externally publishedYes

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