Water-soluble anionic/cationic polyelectrolytes

Copolymerization reactions with ferrocenophanes using transition metal catalysts have also been accomplished. The self-assembly of block copolymers has been examined, and polymers with dimethylsiloxane or ethyleneoxide blocks have been found to be soluble in aqueous solution. These ferrocene-based polymers have been found to self-assemble in solution, and their morphologies have been investigated. A number of water-soluble anionic (26) and cationic (27) polyelectrolytes have also been produced by sidechain functionalization. 

The penetration of ions from the subphase into the shell of spread particles is a general phenomenon and can be used to modify and functionalize the particle surface. For example, metal ions, such as Ba and Fe, or cationic polyelectrolytes, such as the polycation of polyallylamine, can be adsorbed at anionic particles, while anionic water-soluble dyes, such as phthalocyanine tetrasulfonic acid and 1.4-diketo-3.6-diphenylpyrrolo[3.4-c]pyrrole-4, 4 -disulfonic acid (DPPS) [157], can be adsorbed at cationic particles. However, since only a monolayer of the dye is adsorbed, a deep coloration of the particles is not obtained unless a dye with very high absorption coefficient is used [156],... 

In a related application, polyelectrolyte microgels based on crosslinked cationic poly(allyl amine) and anionic polyfmethacrylic acid-co-epoxypropyl methacrylate) were studied by potentiometry, conductometry and turbidimetry [349]. In their neutralized (salt) form, the microgels fully complexed with linear polyelectrolytes (poly(acrylic acid), poly(acrylic acid-co-acrylamide), and polystyrene sulfonate)) as if the gels were themselves linear. However, if an acid/base reaction occurs between the linear polymers and the gels, it appears that only the surfaces of the gels form complexes. Previous work has addressed the fundamental characteristics of these complexes [350, 351] and has shown preferential complexation of cationic polyelectrolytes with crosslinked car-boxymethyl cellulose versus linear CMC [350], The departure from the 1 1 stoichiometry with the non-neutralized microgels may be due to the collapsed nature of these networks which prevents penetration of water soluble polyelectrolyte. 

The adsorption of block copolymers can be controlled by different stimuli, in particular by the pH since most of the brushes formed by block copolymers adsorption are polyelectrolyte brushes [129, 130], The group of Armes, for instance, studied the pH-controlled adsorption of a series of block copolymers [131, 132], In the case of copolymers bearing hydrophobic 2-(diethylamino)ethyl methacrylate groups (DEA) and a water-soluble zwiterionic poly(2-methacryloyl phosphoryl-choline) (MPC) block, they showed that at low pH the cationic DEA flatted to the anionic silicon surface while the MPC was in contact with the solution [132], At around neutral pH, micelles were formed in solution and adsorbed onto the surface because the DEA core was still weakly cationic. The MPC block formed the micelle coronas. Nevertheless, at higher pH the micelles became less cationic and the adsorption rate decreased. 

Over the past 10 years, research into water-soluble ferrocene-based polymers and polyelectrolytes has increased.168-175 Vancso and co-workers have reported the preparation and self-assembly of anionic and cationic polyelectrolytes.171,172 Polyanionic, 89, and polycationic, 90, ferrocene-based electrolytes are two examples of such polyelectrolytes.170... 

Polyelectrolytes are one of the most interesting and utiliz-able polymer materials presently under development. These water soluble polymers may be classified into three main groups nonionic polyelectrolytes, such as polyols, polyethers and polyamides anionic polyelectrolytes, such as carboxylates, sulfonates, and phosphates and cationic polyelectrolytes, such as ammonium, quaternary amines, sulfoniums and phosphoniums (1). These materials have wide and varied industrial applications. 

POLYELECTROLYTE - A water-soluble polymer that is highly charged with cationic or anionic sites. Used as an aid with coagulants. 

Water-soluble paints or lacquers with polyelectrolytes are especially suitable for electroimmersion coatings. Polyanions are mostly used in this process. Anionic deposition produces a very good adhesion to the substrate. On the other hand, cationic deposition has the advantage that the phosphate pickling layer is not attacked and no metal goes into solution at the cathode. 

Water-soluble interpolyelectrolyte complexes (IPECs) formed by cationic cylindrical polyelectrolyte bmshes and linear anionic poly(sodium styrenesulfonate) (PSSNa) have been smdied both theoretically and experimentally by using AFM. ° ° The IPECs were prepared by dialysis of... 

In self-doped polymers, the charge-compensating anion is covalently bound to the polymeric backbone, so that oxidative doping involves the expulsion of cationic species rather than anion insertion. Poly(3-thiophene-) -ethanesulfonate) and poly(3-thiophene-<5-butanesulfo-nate) (23) [171] were first prepared with the sulfonate group, which makes these polymers water-soluble. The polymers have been prepared by electropolymerization of the corresponding methyl esters, followed by hydrolysis to the polyelectrolytic form [171]. Films cast from water solution exhibited a rather short conjugation (maximum absorption at 425 nm, 3.6 eV) and conductivities of 1—10 S cm after doping [172]. 

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