Polyelectrolyte complex properties

Kang HS, Park SH, Lee YG et al (2007) Polyelectrolyte complex hydrogel composed of chitosan and poly(y-glutamic acid) for biological application Preparation, physical properties, and cytocompatibility. J Appl Polym Sci 103 386-394... 

Significant research has been directed toward the use of polyelectrolyte complexes as blood compatible materials. Several investigators found that water-insoluble polyelectrolyte complexes can suppress blood coagulation [487-490]. Davison and coworkers reviewed and studied the biological properties of water-soluble polyelectrolyte complexes [491] between quatemized poly(vinyl imidazole) or polyvinyl pyridine) and excess sulfonated dextran or poly(methacrylic acid). By forming complexes with a stoichiometric excess of anionic charge, a more compact conformation with anionic character was obtained. 

Howard, K.A., Dash, P.R., Read, M.L., Ward, K., Tomkins, L.M., Nazarova, O., Ulbrich, K. and Seymour, L.W. (2000) Influence of hydrophilicity of cationic polymers on the biophysical properties of polyelectrolyte complexes formed by self-assembly with DNA. Biochim. Biophys. Acta., 1475, 245-255. 

Schonhoff M (2003) Layered polyelectrolyte complexes physics of formation and molecular properties. J Phys Condens Matter 15 1781-1808... 

Yancheva E, Paneva D, Maximova V et al. (2007) Polyelectrolyte complexes between (cross-linked) (V-carboxyethylchitosan and (quatemized) poly[2-(dimethylamino)ethyl methacrylate] preparation, characterization, and antibacterial properties. Biomacromolecules... 

Polyelectrolyte complexes of retinoic acid have been well investigated, they are pharmaceutically active surfactants. In the following, we will therefore discuss the physicochemical properties of drug carriers formed by synthetic polyamino acids, polyethyleneimine, double hydrophilic block copolymers and retinoic acid. 

Over recent years, a major development in the field of polyelectrolyte complexes has been the introduction of polyelectrolyte multilayers by Decher [194]. Some of their properties are described in this paper and they have become one of the very efficient and versatile ways of making surface coatings. We very briefly discuss here the implications of the Debye-Hiickel properties of polyelectrolyte complexes for the formation of polyelectrolyte multilayers. 

The formation of polyelectrolyte complexes (PEC) is governed by the characteristics of the individual polyelectrolyte components (e.g. properties of ionic sites - strong or weak electrolyte -, position of ionic sites, charge density, rigidity of macromolecular chains) and the chemical environment (e.g. solvent, ionic strength, pH and temperature). Polyelectrolyte complexes are either separated from the solution as solids or liquids or they are still soluble in solution or may settle as gels due to variation of the controlling factors mentioned above. 

To achieve a wider commercial application of polyelectrolyte complexes, more detailed data on their physical and chemical properties are required. It is generally assumed that polyelectrolyte complexes have unique properties because the main interaction forces are the strong Coulomb forces and their electrostatic nature (net charge) can easily be varied by changing only their composition51 ... 

Michaels et al.50 53) reported the chemical and physical properties of the polyelectrolyte complex of NaSS-PVBMA. This complex is used as a membrane in various fields. Polyelectrolyte complexes prepared by casting homogeneous solutions of ternary-solvent systems mentioned above are transparent and amorphous. Dried polyelectrolyte complexes are hard materials whereas wetted ones are rubber-like or skin-like. The polyelectrolyte complex with an equimolar composition is neutral whereas that with a non-equimolar composition can display ion-exchange properties. The range of the water content depends on the excess of polycation or polyanion in the complex. 

Kig. 21. Mechanical properties of the polyelectrolyte complex of poly(sodium styrenesulfonate) (NaSS)-poly(4-vinylbenzyl-trimethylammonium chloride) (PVBMA)S4). (1) modulus, (2) elongation, (3) tensile strength... 

The electrical properties of polyelectrolyte complexes are more closely related to those of biologically produced solids. The extremely high relative dielectric constants at low frequencies and the dispersion properties of salt-containing polyelectrolyte complexes have not been reported for other synthetic polymers. Neutral polyelectrolyte complexes immersed in dilute salt solution undergo marked changes in alternating current capacitance and resistance upon small variations in the electrolyte concentration. In addition, their frequency-dependence is governed by the nature of the microions. As shown in... 

Fig. 23 a, b. Dielectric properties of polyelectrolyte complexes881 (a) Variation of dielectric constant e and loss factor e" of polyelectrolyte complexes with frequency (b) Variation of loss tangent e"/e of polyelectrolyte complexes with frequency. NaSS = poly(sodium styrenesulfonate), PAA = polyfacrylic add), PVBMA = poly(4-vinylbenzyl-trimethylammonium chloride), PEI = polyethyleneimine, lonene (Bubond 60) = — 2CTK... 

In spite of the comparatively short period of intensive investigation of polyelectrolyte complexes, their outstanding physico-mechanical, dielectric, ion-exchanging and optical properties have roused a great interest in the polymer materials132-1341. 

The first systematic studies on the properties of polyelectrolyte complexes were carried out by A. Michaels et al. - They examined the complexes of strong,... 

Polyelectrolyte complexes are very promising materials for preparing semi-permeable membranes of definite permeability and selectivity The methods of preparation and the properties of membranes made of polyelectrolyte complexes based on strong polyelectrolytes, e.g. poly(sodium sterene sulfonate) and poly(vinylbenzyl-trimethyl ammonium chloride) were described These membranes may be applied for reverse osmosis in the desalting of sea-water, for dialysis and ultrafiltration in purifications and concentration of water solutions containing coUoids or micro-and macroparticles ... 

The first example of an azobenzene amphiphile polyelectrolyte complex was reported by Shimomura and Kunitake. They used poly(vinylsulfate) 23 to stabilize an ammonium amphiphile (21, n = 5). Because the tertiary ammonium head group is rather large and the distance of the ionic sites in poly(vinylsulfate) is rather small, the packing of the amphiphiles is not sipti-ficantly loosened by the complexation. In this case, the influence of the poylelectrolyte on the spectral properties and the photoisomerization is small. 

Stefuca, V. Gemeiner, P. Kurillova, L. Dautzenberg, H. Polakovic, M. Bales, V. Polyelectrolyte complex capsulesas a material for enzyme immobilization, catalytic properties of encapsulated lactate dehydrogenase. Appl. Biochem. Biotechnol. 1991, 30 (3), 313-324. 

Davison, C.J. Smith, K.E. Hutchinson, L.E.F. O Mullane, J. Physical and biological properties of water soluble polyelectrolyte complexes. J. Bioact. Compat. Polym. 1990, 5 (3), 267-282. 

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