Preparation of Spherical and Balloonlike Calcium Phosphate Particles from Forced Hydrolysis of Ca(OH)2-Triphosphate Solution and Their Adsorption Selectivity of Water

AbstractDouble hydrophilic block copolymers were used to control the growth of inorganic particles and directly prepare hybrid colloidal suspensions. Colloids of metal hydrous oxides were obtained by forced hydrolysis of metal ions in presence of the copolymers. The block copolymers contain a metal-complexing polyelectrolyte block and a stabilizing neutral block. The role of the first block is to ensure a controlled growth of the inorganic phase, while simultaneously, the second block ensures the colloidal stabilization. Phase diagrams presenting the conditions under which precipitation is inhibited are established. The nanoparticles are then characterized in terms of sizes, morphologies and surface charges. The main parameters controlling the size were identified: the copolymer-to-metal ratio and the metal prehydrolysis ratio. The synthesis steps were characterized. First, a key step of induced micellization of the hydrophilic copolymers leads to hybrid core-shell assemblies. The second step consists in mineralization of the micellar core. The suspension polycondensation leads to hairy particles whose morphologies depend on the nature of the metal and on synthesis parameters.

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The study of the microstructure of cheese before and after vacuum drying

Biointerface Research in Applied Chemistry ◽

10.33263/briac104.007014 ◽

2020 ◽

Vol 10 (4) ◽

pp. 6007-6014

Keyword(s):

Calcium Phosphate ◽

Surface Shape ◽

Vacuum Drying ◽

Protein Matrix ◽

Fat Globules ◽

Before And After ◽

Calcium Phosphate Particles ◽

Structure State ◽

Cheese Microstructure ◽

Scanning Electron

Scanning electron microscope allowed us to get screens of different cheese microstructure that form a base for further investigation of a cheese structure state before and after the process of drying and for their comparison. Any cheese structure presents a matrix of proteins penetrated with moisture capillaries; fat globules are located both inside the protein matrix and on a cheese surface. Shape of capillaries is either round or oval. Capillaries vary in size and number that has an impact on the cheese pattern which is described by hole and void shapes and order. Electron microscopy was also used for detecting deposition of calcium phosphate. Particles of calcium phosphate changed in size, before drying they were 10–12 µm, and after drying they reached 20–30 µ. These particles concentrate in the dried cheese and agglomerate into larger particles. The most concentrated calcium phosphate proportion was found in pores and micro-voids of the dry cheese. As for mature cheese samples, calcium lactate was established as well.

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Sedimentation Study of Biphasic Calcium Phosphate Particles

Bioceramics 20 - Key Engineering Materials ◽

10.4028/0-87849-457-x.365 ◽

2007 ◽

pp. 365-368

Author(s):

Ahmed Fatimi ◽

Jean Francois Tassin ◽

Monique Aselo V. Axelos ◽

Pierre Weiss

Keyword(s):

Calcium Phosphate ◽

Biphasic Calcium Phosphate ◽

Calcium Phosphate Particles

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Synthesis and characterization of Ti(IV)-substituted calcium hydroxyapatite particles by forced hydrolysis of Ca(OH)2-Na5P3O10-TiCl4 mixed solution

Colloid & Polymer Science ◽

10.1007/s00396-014-3320-y ◽

2014 ◽

Vol 292 (11) ◽

pp. 2849-2856 ◽

Cited By ~ 2

Author(s):

Kazuhiko Kandori ◽

Minori Mitsui

Keyword(s):

Calcium Hydroxyapatite ◽

Synthesis And Characterization ◽

Mixed Solution ◽

Forced Hydrolysis ◽

Hydrolysis Of

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Microfiltration performance: physicochemical aspects of whey pretreatment

Journal of Dairy Research ◽

10.1017/s0022029900030971 ◽

1995 ◽

Vol 62 (2) ◽

pp. 269-279 ◽

Cited By ~ 15

Author(s):

Genevieve Gesan ◽

Georges Daufin ◽

Uzi Merin ◽

Jean-Pierre Labbe ◽

Auguste Quemerais

Keyword(s):

Calcium Phosphate ◽

Membrane Surface ◽

Physicochemical Process ◽

High Shear ◽

Lower Content ◽

Phosphate Ions ◽

Complex Lipid ◽

Ionic Calcium ◽

Calcium Phosphate Particles ◽

Soluble Calcium

SUMMARYClarification of whey by microfiltration (MF) can be achieved after appropriate pretreatment of the feed. A control pretreatment consists of a physicochemical process comprising increased ionic calcium and pH accompanied by heat (50 °C, 15 min) to cause aggregation of complex lipid–calcium phosphate particles, which are then separated by MF. This pretreatment process was modified by increasing the temperature to 55 °C and by maintaining the pH constant during heat treatment. This modification resulted in larger calcium phosphate particles and a lower content of soluble calcium and phosphate ions. As a consequence, a longer period of MF operation, better whey clarification and lower calcium and phosphate content of the filtrate were achieved. This suggests that a loosely structured deposit was formed on the membrane surface which was less resistant to filtration than that resulting from the control pretreatment. During MF, it was necessary to avoid zones of high shear in the retentate compartment that might cause physical alteration of the aggregates.

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