Polymer Dynamics in Layer-by-Layer Assemblies of Chitosan and Heparin
- 18 November 2009
- journal article
- research article
- Published by American Chemical Society (ACS) in Langmuir
- Vol. 26 (5), 3242-3251
- https://doi.org/10.1021/la902968h
Abstract
The layer-by-layer deposition method has been used to build a multilayer thin film with two polysaccharides, chitosan CH (weak polycation) and heparin HEP (strong polyanion), on planar quartz surfaces. The film structure and dynamics in aqueous Solution were studied with fluorescence resonance energy transfer (FRET) and total internal reflection fluorescence (TIRF). Particular emphasis was placed on the effect of deposition conditions, i.e.. pH and salt concentration, on the out-of-plane (vertical) diffusion of fluorescence labeled chitosan in the chitosan/heparin (CH/HEP) film. FRET analysis showed that CH molecules diffused within the film with a diffusion coefficient that was not significantly sensitive to the deposition pH and Solution ionic strength. A pH-sensitive label bound to CH embedded within the CH/HEP Film wits sensitive to the charge of the outermost polymer layer even when buried under 14 alternate layers of CH and HER A consideration of the results obtained with both fluorescence techniques showed that the structure of the CH/HEP thin film wits highly interpenetrated without clear boundaries between each layer. These results are consistent with the hypothesis that the previously observed exponential-like film growth of CH and HEP in terms of, layer thickness and deposited amount versus deposition cycle can be attributed to out-of-plane diffusion of CH molecules in the multilayer.Keywords
This publication has 41 references indexed in Scilit:
- Polyelectrolyte Multilayer Films: From Physico-Chemical Properties to the Control of Cellular ProcessesCurrent Medicinal Chemistry, 2008
- Internal structure of polyelectrolyte multilayer assembliesPhysical Chemistry Chemical Physics, 2006
- Surface Interactions during Polyelectrolyte Multilayer Buildup. 1. Interactions and Layer Structure in Dilute Electrolyte SolutionsLangmuir, 2004
- Comparison of the Structure of Polyelectrolyte Multilayer Films Exhibiting a Linear and an Exponential Growth Regime: An in Situ Atomic Force Microscopy StudyMacromolecules, 2002
- Buildup Mechanism for Poly(l-lysine)/Hyaluronic Acid Films onto a Solid SurfaceLangmuir, 2001
- Hollow Capsule Processing through Colloidal Templating and Self-AssemblyChemistry – A European Journal, 2000
- Thin Polymer Layers Formed by Polyelectrolyte Multilayer Techniques on Biological SurfacesLangmuir, 1999
- Fuzzy Nanoassemblies: Toward Layered Polymeric MulticompositesScience, 1997
- Buildup of ultrathin multilayer films by a self-assembly process: III. Consecutively alternating adsorption of anionic and cationic polyelectrolytes on charged surfacesThin Solid Films, 1992
- Multilayers of colloidal particlesJournal of Colloid and Interface Science, 1966