Adsorption of Highly Charged Polyelectrolytes onto an Oppositely Charged Porous Substrate
2008 (English)In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 24, no 15, 7857-7866 p.Article in journal (Refereed) Published
The adsorption behavior of highly charged cationic polyelectrolytes onto porous substrates is electrostatic in nature and has been shown to be highly dependent on the polyelectrolyte properties. Copolymers of acrylamide (AM) and diallyldimethylammonium chloride (DADMAC) were synthesized to have a range of macromolecular properties (i.e., charge density and molecular mass). Traditional titration methods have been complemented by fluorescence labeling techniques that were developed to directly observe the extent that fluorescently labeled poly(AM-co-DADMAC) adsorbs into the pore structure of a cellulosic Substrate. Although contributing to the electrostatic driving force, the charge density acts to limit adsorption to the outermost surface under electrolyte-free conditions. However, adsorption into the pores call occur if both the molecular mass and charge density of poly(AM-co-DADMAC) are Sufficiently low. Adsorption initially increases as the electrolyte concentration is increased. However, the electrostatic persistence length of poly(AM-co-DADMAC) restricts the polyelectrolyte from entering the pores. Therefore, changes ill the adsorption behavior at moderate electrolyte concentrations have been attributed to swelling of the polyelectrolyte layer at the fiber exterior. The adsorption behavior changes again at high electrolyte concentrations Such that poly(AM-co-DADMAC) could adsorb into the pore Structure. This occurred when the electrolyte concentration was sufficient to screen the electrostatic persistence length of poly(AM-co-DADMAC), provided that the entropic driving force for adsorption still existed. It is suggested that adsorption into the pore structure is a kinetic process that is governed by localized electrostatic interactions between poly(AM-co-DADMAC) and the charges located within the pores.
Place, publisher, year, edition, pages
2008. Vol. 24, no 15, 7857-7866 p.
Amides; Amplitude modulation; Charge density; Concentration (process); Electrolysis; Electrolytes; Electrostatics; Fees and charges; Fiber optics; Finance; Hydrogels; Labeling; Molecular mass; Polyelectrolytes; Polymers; Pore structure; Substrates; Surface charge; Titration; Volumetric analysis; Acrylamide; Adsorption behavior; Cationic polyelectrolytes; Charged polyelectrolytes; Diallyldimethylammonium chloride; Driving forces; Electrolyte concentrations; Electrolyte properties; Electrostatic driving; Electrostatic interactions; Fluorescence labeling; Kinetic processes; Persistence lengths; Porous substrates
Paper, Pulp and Fiber Technology
IdentifiersURN: urn:nbn:se:kth:diva-8451DOI: 10.1021/la800093mISI: 000258034500034ScopusID: 2-s2.0-49649115957OAI: oai:DiVA.org:kth-8451DiVA: diva2:13776
QC 20100811. Uppdaterad från accepted till published (20100811).2008-05-152008-05-152010-08-11Bibliographically approved