Adsorption of Low Charge Density Polyelectrolytes to an Oppositely Charged Porous Substrate
2008 (English)In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 24, no 13, 6585-6594 p.Article in journal (Refereed) Published
The adsorption behavior of a low charge density cationic polyelectrolyte to cellulosic fibers has been studied. Cationic dextran served as a model polyelectrolyte, as it can be prepared over a range in molecular mass and charge density. The adsorption behavior of the cationic dextran was measured in electrolyte-free conditions using polyelectrolyte titration techniques. By fluorescent labeling the cationic dextran, the extent to which adsorption occurs inside the porous structure was further determined by fluorescent confocal laser scanning microscopy. Cationic dextran having a sufficiently low charge density adsorbed into the pores, although the extent the cationic dextran adsorbed was governed by the molecular mass. The adsorption behavior of the cationic dextran was also studied in various electrolyte concentrations. The adsorbed mass monotonically decreased with increasing electrolyte, as the electrostatic interaction with the substrate was more effectively screened. This behavior also suggests that the interactions between adsorbed polyelectrolyte chains, i.e. lateral correlation effects, are negligible for low charge density polyelectrolytes. Finally, the effect of having a preadsorbed layer of cationic dextran on the adsorption behavior was determined in electrolyte-free conditions using fluorescent double staining techniques. The preadsorbed cationic dextran had almost no effect on the adsorption of low molecular mass fractions. Low molecular mass fractions directly adsorbed into the pore structure, as opposed to adsorbing to a free surface and diffusing into the pores. It was also shown that cationic dextran can be selectively adsorbed to different locations, such that the surface of a porous substrate can be treated uniquely from the bulk.
Place, publisher, year, edition, pages
2008. Vol. 24, no 13, 6585-6594 p.
Adsorption; Charge density; Confocal microscopy; Electrolysis; Electrolytes; Flow interactions; Fluorescence; Glucose; Imaging techniques; Labeling; Light emission; Luminescence; Molecular mass; Painting; Polyelectrolytes; Polymers; Pore structure; Pulsed laser deposition; Substrates; Theorem proving; Volumetric analysis; Adsorption behavior; American Chemical Society (ACS); Cationic polyelectrolytes; Cellulosic fibers; Confocal laser scanning micro scopy (CLSM); Electrolyte concentrations; Electrostatic interactions; Fluorescent labeling; Free surfaces; Lateral correlation; Low charge density polyelectrolytes; Low molecular mass (LMM); Monotonically; Polyelectrolyte chains; Porous structures; Porous substrates; Staining techniques
Paper, Pulp and Fiber Technology
IdentifiersURN: urn:nbn:se:kth:diva-8452DOI: 10.1021/la800274wISI: 000257101100029ScopusID: 2-s2.0-47349132325OAI: oai:DiVA.org:kth-8452DiVA: diva2:13777
QC 20100811. Uppdaterad från accepted till published (20100811).2008-05-152008-05-152010-08-11Bibliographically approved