Influence of Ph on the Formation of Polyphosphate Coacervates

Gomez, F.; Vast, P.; Willot, G.

doi:10.3363/prb1992.11.0_53

Cited by 5 publications

(3 citation statements)

References 7 publications

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“…This work confirms previous results about the obtention of coacervates [8,22,25]. The assumption that the coacervation phenomenon requires an acidic pH is erroneous, although this statement was made for zinc coacervate [14,15].…”

Section: Discussionsupporting

confidence: 89%

“…1. In this figure, concentrations are expressed in moles and the line of the diagram links indicates the two-phase system (coacervate/equilibrium liquid) when starting from a sodium polyphosphate solution [22].The limit of coacervation for a mixture with a too high ZnCl 2 /NaPO 3 ratio is given by the points in the right part of Fig. 1.…”

Section: Concentration Conditionsmentioning

confidence: 99%

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Preparation of zinc sodium polyphosphates glasses from coacervates precursors. Characterisation of the obtained glasses, and their applications

Willot

Gomez

Vast

et al. 2002

Comptes Rendus. Chimie

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A soft chemistry route is described to obtain glasses in the P 2 O 5 -Na 2 O-ZnO-H 2 O. It is based on the addition of zinc salts to coacervates prepared from sodium polyphosphate. The processing of these coacervates leads to polyphosphate glasses with the same properties as those of glasses prepared in the classical way. So far, little work has been implemented in this system using 'coacervate route'. However, it makes an attractive method for coating and joining processes on the industrial scale. As the anion associated to zinc may take part in the adhesion mechanism, coacervate formation has been studied using zinc chloride, nitrate and sulphate as starting materials. The physical properties of the glasses obtained by this method are reported and potential applications of zinc and silver coacervate are described. To cite this article: G. Willot et al., C. R. Chimie 5 (2002) 899-906 © 2002 Académie des sciences / Éditions scientifiques et médicales Elsevier SAS glass / polyphosphate / coacervate / coating / sealingRésumé -Nous décrivons une nouvelle méthode permettant d'obtenir par voie douce des verres dans le système P 2 O 5 -Na 2 O-ZnO-H 2 O. Elle est basée sur la formation de coacervats de polyphosphates obtenus par l'action de sels de zinc sur des solutions concentrées de polyphosphate de sodium. Par chauffage, on obtient, à des températures de l'ordre de 400 °C, des phases vitreuses ayant les mêmes propriétés que les verres obtenus par une méthode classique. Cependant, compte tenu des propriétés des coacervats, cette méthode permet de développer des procédés de collage ou de revêtements applicables en milieu industriel. Comme les anions associés aux sels de zinc utilisés peuvent intervenir dans les mécanismes d'adhésion, nous avons étudié plus en détail les mécanismes de formation des coacervats à partir des chlorure, nitrate et sulfate de zinc. Nous donnons les propriétés physiques des verres obtenus par ce procédé, ainsi que les potentialités de verres obtenus à la fois à partir de coacervats de zinc et d'argent.

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Section: Discussionsupporting

confidence: 89%

Section: Concentration Conditionsmentioning

confidence: 99%

Preparation of zinc sodium polyphosphates glasses from coacervates precursors. Characterisation of the obtained glasses, and their applications

Willot

Gomez

Vast

et al. 2002

Comptes Rendus. Chimie

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“…These are generally obtained by double decomposition between soluble calcium and phosphate salt precursors, and some processes lead to dense liquid "coacervates" [11]. Several kinds of phosphate precursors have been used: long-chain polyphosphates (polyP) [12,13], cyclic polyphosphates [14], diphosphates (also called pyrophosphates: P 2 O 7 4-) [15][16][17] or orthophosphates (PO 4 3-) [10]. Without any high temperature treatment, the polyP associations are preserved in the final materials, which remain amorphous.…”

Section: Introductionmentioning

confidence: 99%

A soft-chemistry approach to the synthesis of amorphous calcium ortho/pyrophosphate biomaterials of tunable composition

et al. 2020

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The development of amorphous phosphate-based materials is of major interest in the field of biomaterials science, and especially for bone substitution applications. In this context, we herein report the synthesis of gel-derived hydrated amorphous calcium/sodium ortho/pyrophosphate materials at ambient temperature and in water. For the first time, such materials have been obtained in a large range of tunable orthophosphate/pyrophosphate molar ratios. Multi-scale characterization was carried out thanks to various techniques, including advanced multinuclear solid state NMR. It allowed the quantification of each ionic/molecular species leading to a general formula for these materials: [(Ca 2+ y Na + z H + 3+x-2y-z)(PO 4 3−) 1−x (P 2 O 7 4−) x ](H 2 O) u. Beyond this formula, the analyses suggest that these amorphous solids are formed by the aggregation of colloids and that surface water and sodium could play a role in the cohesion of the whole material. Although the full comprehension of mechanisms of formation and structure is still to be investigated in detail, the straightforward synthesis of these new amorphous materials opens up many perspectives in the field of materials for bone substitution and regeneration.

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Iron Polyphosphate Coacervate. A New Route for the Treatment of Inorganics Wastes ?

Walbrou

Aldon

Vast

et al. 2001

Phosphorus Research Bulletin

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The use of phosphate glasses based on the system iron sodium for the treatment of inorganic waste has been soon proposed. The coacervation of polyphosphates permits to formulate glass precursor in aqueous media and at room temperature from the mix FeCl2-NaPO3. The rheologic properties permit to coat each particle of the waste before the curing step. In this paper we determine the conditions of coacervate's formation. By Mossbauer spectroscopy, we show that the iron stays always in a ferrous state during the coacervate formation. It confirm also the presence of chlorine ions in the coacervate. By curing the coacervates give glasses and a part of iron is oxidised in a ferric state even in argon atmosphere. Mossbauer hyperfine parameters indicate that both Fe II and Fe III ions are in octahedral or pseudo octahedral coordination.

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Influence of Ph on the Formation of Polyphosphate Coacervates

Cited by 5 publications

References 7 publications

Preparation of zinc sodium polyphosphates glasses from coacervates precursors. Characterisation of the obtained glasses, and their applications

Preparation of zinc sodium polyphosphates glasses from coacervates precursors. Characterisation of the obtained glasses, and their applications

A soft-chemistry approach to the synthesis of amorphous calcium ortho/pyrophosphate biomaterials of tunable composition

Iron Polyphosphate Coacervate. A New Route for the Treatment of Inorganics Wastes ?

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