Phosphate bonding with several calcined aluminas

Toy, Ç.; Whittemore, O. J.

doi:10.1016/0272-8842(89)90012-6

Cited by 23 publications

(7 citation statements)

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“…The adsorption-desorption of phosphate on aluminum hydroxides and oxides has been the subject of intense study for decades [5][6][7][8][9][10]. Some of the studies aimed at a better understanding of the adsorption mechanisms of strongly bound anions on aluminum (hydr)oxides.…”

Section: E-mail Address: Wgds@rceesaccn (D Wang)mentioning

confidence: 99%

“…The surface charge, Q H (mol L −1 ), was calculated directly from the measured pH and the amount of acid or base added at each data point [9,10] as follows: where C A and C B (mol L −1 ) were the concentrations of acid and base added to the suspension, respectively. Since the titration procedure was finished within 5 h and in the moderate pH domain (4-10), the dissolution of the samples were negligible (Fig.…”

Section: Potentiometric Titrationsmentioning

confidence: 99%

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Adsorption of phosphate at the aluminum (hydr)oxides–water interface: Role of the surface acid–base properties

Yang

Wang

Sun

et al. 2007

Colloids and Surfaces A: Physicochemical and Engineering Aspect

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In this paper, the adsorption of phosphate on two crystallized aluminum oxides, pseudo-boehmite (pseudo-␥-AlOOH) and ␣-Al 2 O 3 , was studied. The adsorption experiments were carried out in 0.01 M KNO 3 solutions at pH 4 and 6, respectively. Adsorption densities were calculated to evaluate the phosphate adsorption affinity for the two aluminum oxides. To better understand the effect of surface properties on the adsorption behavior of phosphate, the surface structure and properties were investigated with X-ray diffraction, N 2 adsorption-desorption, electron microscope observation and surface acid-base titrations. The results from adsorption isotherms showed that at both pH 4 and 6, pseudo-␥-AlOOH exhibited greater adsorption capacity than ␣-Al 2 O 3 . For both pseudo-␥-AlOOH and ␣-Al 2 O 3 , the adsorbed amount of phosphate at pH 4 was higher than that at pH 6. Adsorption density calculation indicated that ␣-Al 2 O 3 had greater affinity for phosphate than pseudo-␥-AlOOH. Information gained from examinations of surface properties revealed that the specific surface area played an important role on adsorption capacity, while the acidity of surface aluminol groups evaluated from acid-base titration curves contributed more to adsorption affinity and consequently the adsorption density.

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Section: E-mail Address: Wgds@rceesaccn (D Wang)mentioning

confidence: 99%

Section: Potentiometric Titrationsmentioning

confidence: 99%

Adsorption of phosphate at the aluminum (hydr)oxides–water interface: Role of the surface acid–base properties

Yang

Wang

Sun

et al. 2007

Colloids and Surfaces A: Physicochemical and Engineering Aspect

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“…Chemical (phosphoric acid, silicates, geopolymers, etc.) [33], [35] 3. Sol-gel (colloidal silica or alumina) [33] Regarding the chemical ones, the bond strength can be provided by the addition of phosphates (dry or solution) or by in situ generation of phosphates (formed via the reaction with added H 3 PO 4 ) in the refractory structure.…”

Section: Ceramics and Refractoriesmentioning

confidence: 99%

Utilization of Compounds of Phosphorus

Ptáček¹

2016

Apatites and Their Synthetic Analogues - Synthesis, Structure, Properties and Applications

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The last chapter of this book provides brief description of utilization of apatites and phosphorus-bearing compounds in industry and material science research. Since the chemistry of phosphorus is quite complicated and a quickly developing field of science, the topics described below are only limited insights to chemically bonded ceramics and refractories, dental phosphate cements, oil-well cements, phosphate glasses and glass ceramics. Chapter continues with description of functional phosphate materials applied as solid oxide fuel cells electrolytes, sensors, phosphors, catalysts and coatings. The chapter ends with introduction of basic ideas for biological apatite in bone tissue engineering, collagen apatite composites, apatite layers and biocoatings.

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Section: Introductionmentioning

confidence: 99%

“…Reasons are their excessive and uncontrollable reactivities with ceramic bodies and their generally great potential to endanger health and the environment. [5][6][7] In practice it is, therefore, preferred to promote the development of powdered inorganic phosphates, for example, for their use as binders in hightemperature applications. 8,9 Most frequently, the aluminum phosphate Al(H 2 PO 4 ) 3 is applied, because it is well soluble in water and achieves a high initial strength.…”

Section: Introductionmentioning

confidence: 99%

Phase development of phosphate‐bonded Al₂O₃‐MgAl₂O₄ high‐temperature ceramics: XRD and solid‐state NMR investigations

et al. 2021

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This article describes investigations on the phase development (T ≤ 1500 °C) of phosphate-bonded Al 2 O 3 -MgAl 2 O 4 high-temperature ceramics by a combination of solid state MAS NMR and X-ray diffraction analyses. The ceramic body was bonded with inorganic hydrogen orthophosphates (Al, Mg, Ca, Zr) with a total binder content of 3 wt.% P 2 O 5 . The binding mechanisms of these phosphate-bonded ceramics could be extensively deduced by analyses of phase developments during hardening, strength development, and hightemperature phase formation at T ≤ 1500 °C: The formation of a network of aluminium phosphate compounds by acid and condensation reactions of the phosphate with the ceramic body is proven to be the active binding process. The binding process is initiated by the formation of active phosphoric acid phosphate phases, which in principle prerequisites water solubility of the binder. Thermal treatment, especially at T ≤ 600 °C, promotes the degree of P-cross-linking of the phosphate structures. In addition to these phosphate-ceramic reactions, it was also possible to identify parallel pure phosphate-phosphate conversions of the initial phosphates (via condensation and polymerisation) without reactions with ceramic components. The contribution of these structures to the binding effect can be estimated to be minor. Only at temperatures of T ≥ 600 °C, these Ca, Mg and Zr phosphates begin to react with the ceramic material to form aluminium phosphates. The phosphate bond has a permanent effect until formation of the ceramic bond (T > 1000 °C). High-temperature phases are usually crystalline PO 4 sintered structures which are formed by reaction with MgAl 2 O 4 .

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Phosphate bonding with several calcined aluminas

Cited by 23 publications

References 1 publication

Adsorption of phosphate at the aluminum (hydr)oxides–water interface: Role of the surface acid–base properties

Adsorption of phosphate at the aluminum (hydr)oxides–water interface: Role of the surface acid–base properties

Utilization of Compounds of Phosphorus

Phase development of phosphate‐bonded Al₂O₃‐MgAl₂O₄ high‐temperature ceramics: XRD and solid‐state NMR investigations

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Phosphate bonding with several calcined aluminas

Cited by 23 publications

References 1 publication

Adsorption of phosphate at the aluminum (hydr)oxides–water interface: Role of the surface acid–base properties

Adsorption of phosphate at the aluminum (hydr)oxides–water interface: Role of the surface acid–base properties

Utilization of Compounds of Phosphorus

Phase development of phosphate‐bonded Al2O3‐MgAl2O4 high‐temperature ceramics: XRD and solid‐state NMR investigations

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Phase development of phosphate‐bonded Al₂O₃‐MgAl₂O₄ high‐temperature ceramics: XRD and solid‐state NMR investigations