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New insights into the structure of polyelectrolyte complexes
- Source :
-
Journal of Colloid & Interface Science . Aug2007, Vol. 312 Issue 2, p237-246. 10p. - Publication Year :
- 2007
-
Abstract
- Abstract: 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 of low charged cationic PAH–PAA PECs on silica surfaces increased if the pH value was increased from pH 5.5 to 7.5. [Copyright &y& Elsevier]
- Subjects :
- *SEPARATION (Technology)
*EVAPORATION (Chemistry)
*MICROSCOPY
*CURING
Subjects
Details
- Language :
- English
- ISSN :
- 00219797
- Volume :
- 312
- Issue :
- 2
- Database :
- Academic Search Index
- Journal :
- Journal of Colloid & Interface Science
- Publication Type :
- Academic Journal
- Accession number :
- 25488582
- Full Text :
- https://doi.org/10.1016/j.jcis.2007.03.075