Spectroscopic study (u.v.-visible and electron paramagnetic resonance) of the interactions between synthetic polycarboxylates and copper ions

Elaboration and characterization of poly (acrylic acid-co-crotonic acid) copolymers: Application to extraction of metal cations Pb(II), Cd(II) and Hg(II) by complexation in aqueous media

“…During the last decades their production has been intensively developing, as example the worldwide production of acrylamide exceeds 400.000 tons/ year [1]. Among polymers, we are interested by polyacrylic acid (PAA) [2,3] and polymethacrylic acid (PMAA) [4,5] which are frequently selected as models to study the complexation properties of metal ions by the natural organic matter such as the humic substances [6,7]. PAA are used as complex ligands with regard to many cations like the alkalines, rare earths and transition elements which have a negative effect on the ecosystem.…”

Physicochemical study of the complexation of poly(acrylic acid) with Cu2+ ions in water

“…(9), that is, assuming that the stoichiometry of the complex is two carboxylate groups per Cu 21 ion. Because of the limitations of the potentiometric method discussed previously, the results in Figure 8 are restricted in the neutralization region of 0 i 25 who combined spectrophotometric and EPR results.…”

Poly(sodium acrylate) hydrogels as potential pH-sensitive sorbents for the removal of model organic and inorganic pollutants from water

“…The strong green-blue color of the hydrogel results both form the increased concentration of Cu 2+ ions in the volume of the hydrogel and from the polymer-metal ion complexation. In fact, it is known that the extinction coefficient is greatly enhanced upon complexation of PANa with Cu 2+ ions, while the absorption band is shifted towards ~720 nm (Francois et al, 1997). Similar adsorption experiments were performed using Crystal Violet.…”

“…The combination of electrostatic attractions with hydrophobic interactions is usually the driving force in the case of cationic organic species, while polymer/metal ion coordination complexes are often formed when higher valency metal ions are involved. For (Francois et al, 1997;Gregor et al, 1955;Ikeda et al, 1998;Mun et al, 2003;Rivas et al, 2005;Yokoi et al, 1986). For simplicity reasons, the PANa-Cu 2+ complexation can be described by eq.…”

“…suggesting that complexation involves two carboxylate groups per Cu 2+ ion (Francois et al, 1997;Kislenko and Verlinskaya, 2001;Mandel and Leyte, 1964;Morawetz, 1955).…”