Reversible formation of iron(<scp>III</scp>) ion clusters in the poly(acrylic acid)–Fe<sup>3+</sup>complex gel with changes in the water content

Yokoi, Hiroshi; Nomoto, Eigo; Ikoma, Shuji

doi:10.1039/jm9930300389

Cited by 17 publications

(16 citation statements)

References 6 publications

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“…The role of this polymer was to complex the iron ions and thus to limit the growth of the nanoparticles during co-precipitation. When polyanions, such as poly(acrylic acid), are used for this purpose, they rather form gels with iron(III) ions (Yokoi et al 1993). The parameters of the SPIONs synthesis were carefully optimized varying the conditions, such as concentration of the reagents, temperature, stirring method and speed, and sonication protocol, to obtain the nanoparticles of preferred properties.…”

Section: Resultsmentioning

confidence: 99%

Stable aqueous dispersion of superparamagnetic iron oxide nanoparticles protected by charged chitosan derivatives

et al. 2012

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This article presents the synthesis and characterization of biocompatible superparamagnetic iron oxide nanoparticles (SPIONs) coated with ultrathin layer of anionic derivative of chitosan. The water-based fabrication involved a two-step procedure. In the first step, the nanoparticles were obtained by co-precipitation of ferrous and ferric aqueous salt solutions with ammonia in the presence of cationic derivative of chitosan. In the second step, such prepared materials were subjected to adsorption of oppositely charged chitosan derivative which resulted in the preparation of negatively charged SPIONs. They were found to develop highly stable dispersion in water. The core size of the nanocoated SPIONs, determined using transmission electron microscopy, was measured to be slightly above 10 nm. The coated nanoparticles form aggregates with majority of them having hydrodynamic diameter below 100 nm, as measured by dynamic light scattering. Their composition and properties were studied using FTIR and thermogravimetric analyses. They exhibit magnetic properties typical for superparamagnetic material with a high saturation magnetization value of 123 ± 12 emu g−1 Fe. Very high value of the measured r2 relaxivity, 369 ± 3 mM−1 s−1, is conducive for the potential application of the obtained SPIONs as promising contrast agents in magnetic resonance imaging.Electronic supplementary materialThe online version of this article (doi:10.1007/s11051-012-1372-9) contains supplementary material, which is available to authorized users.

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Section: Resultsmentioning

confidence: 99%

Stable aqueous dispersion of superparamagnetic iron oxide nanoparticles protected by charged chitosan derivatives

et al. 2012

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“…This may be attributed to the fact that the interactions between CS and PAA screen the interactions between ferric ions and PAA. 12,44,45…”

Section: Resultsmentioning

confidence: 99%

Evaluation of Single Hydrogel Nanofiber Mechanics Using Persistence Length Analysis

et al. 2018

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Polyelectrolyte hydrogel fibers can mimic the extracellular matrix and be used for tissue scaffolding. Mechanical properties of polyelectrolyte nanofibers are crucial in manipulating cell behavior, which metal ions have been found to enable tuning. While metal ions play an important role in manipulating the mechanical properties of the fibers, evaluating the mechanical properties of a single hydrated hydrogel fiber remains a challenging task and a more detailed understanding of how ions modulate the mechanical properties of individual polyelectrolyte polymers is still lacking. In this study, dark-field microscopy and persistence length analysis help directly evaluate fiber mechanics using electrospun fibers of poly(acrylic acid) (PAA), chitosan (CS), and ferric ions as a model system. By comparing the persistence length and estimated Young’s modulus of different nanofibers, we demonstrate that persistence length analysis is a viable approach to evaluate mechanical properties of hydrated fibers. Ferric ions were found to create shorter and stiffer nanofibers, with Young’s modulus estimated at a few kilopascals. Ferric ions, at low concentration, reduce the Young’s modulus of PAA and PAA/CS fibers through the interaction between ferric ions and carboxylate groups. Such interaction was further supported by nanoscale infrared spectroscopy studies of PAA and PAA/CS fibers with different concentrations of ferric ions.

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“…We have to mention that the investigation of the complexation of Pu(IV) with PAA was often disturbed by the formation of hydrogels, resulting from cross-linking of the polymer molecules by Pu(IV). The formation of these gels is known for some transition metals like Fe(III), Zr(IV), Hf(IV) and Ti(IV) [40,41]. These disturbances can be diminished by keeping the PAA:Pu(IV) ratio as high as possible.…”

Section: Complexation Of Pu(iv) With Paa and Paa-co-mamentioning

confidence: 94%

Investigations on the interactions between plutonium and synthetic water-soluble polymers

Gerstmann¹,

Lierse²,

Geckeler³

2001

Radiochimica Acta

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The interactions between Pu(IV) and Pu(VI), respectively, and some synthetic water-soluble polymers were investigated by absorption spectroscopy and ultrafiltration. Depending on the type of polymer plutonium can be bound by different mechanisms. Poly(acrylic acid) binds Pu(IV) and Pu(VI) by stepwise complexation, which can be observed by absorption spectroscopy. Due to chelation, some of the formation constants are greater than those from corresponding complexes with low-molecular carboxylic acids. By poly(styrenesulfonic acid) and poly(vinylesulfonic acid), Pu(IV) is bound via counterion condensation. In nitrate and chloride media, anionic Pu(IV) complexes may be bound by quaternary ammonium polymers like poly(diallydimethylammonium chloride) and permethylated poly(ethyleneimine).

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Reversible formation of iron(III) ion clusters in the poly(acrylic acid)–Fe³⁺complex gel with changes in the water content

Cited by 17 publications

References 6 publications

Stable aqueous dispersion of superparamagnetic iron oxide nanoparticles protected by charged chitosan derivatives

Stable aqueous dispersion of superparamagnetic iron oxide nanoparticles protected by charged chitosan derivatives

Evaluation of Single Hydrogel Nanofiber Mechanics Using Persistence Length Analysis

Investigations on the interactions between plutonium and synthetic water-soluble polymers

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Reversible formation of iron(III) ion clusters in the poly(acrylic acid)–Fe3+complex gel with changes in the water content

Cited by 17 publications

References 6 publications

Stable aqueous dispersion of superparamagnetic iron oxide nanoparticles protected by charged chitosan derivatives

Stable aqueous dispersion of superparamagnetic iron oxide nanoparticles protected by charged chitosan derivatives

Evaluation of Single Hydrogel Nanofiber Mechanics Using Persistence Length Analysis

Investigations on the interactions between plutonium and synthetic water-soluble polymers

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Product

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Reversible formation of iron(III) ion clusters in the poly(acrylic acid)–Fe³⁺complex gel with changes in the water content