New insights into the structure of polyelectrolyte complexes
2007 (English)In: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 312, no 2, 237-246 p.Article in journal (Refereed) Published
The formation of polyelectrolyte complexes (PECs) from oppositely charged linear polyelectrolytes (PELs) was studied using static light scattering at various salt concentrations. The PELs used were poly(allylamine hydro chloride) (PAH) and the two polyanions poly(acrylic acid) (PAA) and poly(methacrylic acid) (PMAA). Physical characteristics such as the radii of gyration, molecular weights, and water contents of the PECs were determined at various molar mixing ratios. Despite relatively small differences in chemical structure between PAA and PMAA, fairly large differences were detected in these physical characteristics. Generally, PECs comprising PMAA were larger and contained more water. Moreover, by using cryogenic transmission electron microscopy, transmission microscopy and atomic force microscopy, shape and structure of the prepared PECs were investigated both in solution and after drying. The PECs were found to be spherical in solution and the shape was retained after freeze-drying. PECs adsorbed on silica surfaces and dried in air at room-temperature still showed a three-dimensional structure. However, the relatively low aspect ratios indicated that the PECs collapsed significantly due to interactions with the silica during adsorption and drying. At intermediate ionic strengths (1-10 mM), stagnation point adsorption reflectometry (SPAR) showed that the adsorption oflow charged cationic PAH-PAA PECs on silica surfaces increased if the pH value was increased from pH 5.5 to 7.5.
Place, publisher, year, edition, pages
2007. Vol. 312, no 2, 237-246 p.
polyelectrolyte complex, poly(acrylic acid), poly(niethacrylic acid), poly(allylamine hydro chloride), structure, water content, Cryo-TEM, AFM, light scattering, poly-electrolyte complexes, light-scattering, supermolecular structures, cationic polymers, adsorption, dispersions, improvement, microscopy, particles, strength
Paper, Pulp and Fiber Technology
IdentifiersURN: urn:nbn:se:kth:diva-16769DOI: 10.1016/j.jcis.2007.03.075ISI: 000247838300008ScopusID: 2-s2.0-34250687914OAI: oai:DiVA.org:kth-16769DiVA: diva2:334812
QC 201005252010-08-052010-08-052010-08-25Bibliographically approved