Fluorescence Investigations into Complex Coacervation between Polyvinylimidazole and Sodium Alginate.

TitleFluorescence Investigations into Complex Coacervation between Polyvinylimidazole and Sodium Alginate.
Publication TypeJournal Article
Year of Publication2009
AuthorsSrivastava, A, Waite, JH, Stucky, GD, Mikhailovsky, A
JournalMacromolecules
Volume42
Issue6
Pagination2168-2176
Date Published2009 Mar 24
ISSN0024-9297
Abstract

Electrostatic interactions between the imidazole-based cationic homopolymer, polyvinylimidazole (PVIm), and anionic polysaccharide, sodium alginate, lead to the formation of colloidal aggregates known as complex coacervates in the pH range 4-6.5. PVIm was labeled with the fluorescent reporter pyrene to investigate the coacervation-induced changes in and around PVIm chains. While the pyrene-tagged PVIm had blue fluorescence in water, the coacervate phase exhibited an additional broad band around 492 nm (green) due to formation of pyrene excimers. Fluorescence spectroscopic investigations point toward aggregation of PVIm chains and desolvation upon coacervation. Highly anisotropic fluorescence emission indicates tight packing of the polymer chains in the coacervate. Confocal microscopy of fluorescein-labeled alginate and rhodamine-labeled PVIm shows coacervates as dense aggregates with uniform distribution of the polymers. Fluorescence spectroscopy offers sensitive and easy investigation into polyelectrolyte interactions.

DOI10.1021/ma802174t
Alternate JournalMacromolecules
PubMed ID20808713
PubMed Central IDPMC2929675
Grant ListR01 DE015415 / DE / NIDCR NIH HHS / United States
R01 DE015415-03 / DE / NIDCR NIH HHS / United States
R01 DE015415-04 / DE / NIDCR NIH HHS / United States