The Calcium Phosphate−Calcium Carbonate System: Growth of Octacalcium Phosphate on Calcium Carbonates

AbstractWe report a synthesis strategy for pure hydroxyapatite (HAp) using an amorphous calcium carbonate (ACC) colloid as the starting source. Room-temperature phosphorylation and subsequent calcination produce pure HAp via intermediate amorphous calcium phosphate (ACP). The pre-calcined sample undergoes a competitive transformation from ACC to ACP and crystalline calcium carbonate. The water content, ACC concentration, Ca/P molar ratio, and pH during the phosphorylation reaction play crucial roles in the final phase of the crystalline phosphate compound. Pure HAp is formed after ACP is transformed from ACC at a low concentration (1 wt%) of ACC colloid (1.71 < Ca/P < 1.88), whereas Ca/P = 1.51 leads to pure β-tricalcium phosphate. The ACP phases are precursors for calcium phosphate compounds and may determine the final crystalline phase.

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Microwave-Assisted Fabrication of Mesoporous Silica-Calcium Phosphate Composites for Dental Application

Polymers ◽

10.3390/polym13010053 ◽

2020 ◽

Vol 13 (1) ◽

pp. 53

Author(s):

Adrian Szewczyk ◽

Adrianna Skwira ◽

Marta Ginter ◽

Donata Tajer ◽

Magdalena Prokopowicz

Keyword(s):

Calcium Phosphate ◽

Mesoporous Silica ◽

Octacalcium Phosphate ◽

Precipitation Method ◽

X Ray Diffraction ◽

Coating Solution ◽

X Ray ◽

Microwave Assisted ◽

Calcium Orthophosphates ◽

Different Types

Herein, the microwave-assisted wet precipitation method was used to obtain materials consisting of mesoporous silica (SBA-15) and calcium orthophosphates (CaP). Composites were prepared through immersion of mesoporous silica in different calcification coating solutions and then exposed to microwave radiation. The composites were characterized in terms of molecular structure, crystallinity, morphology, chemical composition, and mineralization potential by Fourier-transform infrared spectroscopy (FTIR), powder X-ray diffraction (XRD), and scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy (SEM-EDX). The application of microwave irradiation resulted in the formation of different types of calcium orthophosphates such as calcium deficient hydroxyapatite (CDHA), octacalcium phosphate (OCP), and amorphous calcium phosphate (ACP) on the SBA-15 surface, depending on the type of coating solution. The composites for which the progressive formation of hydroxyapatite during incubation in simulated body fluid was observed were further used in the production of final pharmaceutical forms: membranes, granules, and pellets. All of the obtained pharmaceutical forms preserved mineralization properties.

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Synthesis, Characterization and Properties of the IA / SAS Copolymer

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.423-426.404 ◽

2013 ◽

Vol 423-426 ◽

pp. 404-407

Author(s):

Zhen Fa Liu ◽

Hao Lin Fu ◽

Li Hui Zhang ◽

Yan He Zhang ◽

Xuan Liu

Keyword(s):

Calcium Carbonate ◽

Calcium Phosphate ◽

Itaconic Acid ◽

Inhibition Rate ◽

Biodegradation Rate ◽

Scale Inhibition ◽

Good Scale

A copolymer was prepared from itaconic acid (IA) and sodium allysulfonate (SAS). The structure of the IA/SAS copolymer was characterized by the means of FTIR. The performances of scale inhibition, dispersion and biodegradability of the IA/SAS copolymer were studied. The results showed that the IA/SAS copolymer had good scale inhibition and dispersing performance. The scale inhibition rate on calcium carbonate was 93% when the copolymer was 20 mg·L-1. The scale inhibition rate on calcium phosphate was 92% when the copolymer was 24 mg·L-1. The copolymer had good biodegradation performance and biodegradation rate could reach 69.5% after 28 days.

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