Morphological evolution of precipitates during transformation of amorphous calcium phosphate into octacalcium phosphate in relation to role of intermediate phase

Yuki Sugiura, Kazuo Onuma, Yuki Kimura, Hitoshi Miura, Katsuo Tsukamoto

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

Nucleation of amorphous calcium phosphate (ACP) and its phase transformation with a decrease in solution pH were investigated at a constant temperature of 32 °C. A solution containing a mixture of CaCl2 and KH2PO4 was prepared (initial pH=7.7), and a drop was sampled at a constant interval to observe the morphological evolution of the precipitates that formed in the solution. A gel-like solution structure formed immediately after mixing and contained a small amount of sea-urchin-like ACP spherulites (320 μm in size). These spherulites consisted of 1.510-μm-long flexible needles that formed simultaneously with numerous ACP spherical particles. They first transformed into β-tri calcium phosphate-like material (called pseudo β-TCP) and then into single crystals of octacalcium phosphate (OCP) without dissolution. The flexible needles in the spherulites changed into blade springs, then into flexible plates, and finally into rigid plates during the transformation. The OCP structure appeared in the pseudo β-TCP plates and gradually substituted for the β-TCP structure over time. The macroscopic spherulite morphology of the initial ACP remained unchanged during the phase transformation, suggesting that OCP is a pseudomorph of ACP. This feature was observed only when the ACP spherulites formed in the initial solution. Fiber-like aggregates consisting of β-TCP single crystals nucleated around the ACP spherical particles and grew over time. They survived until the final stage of the reaction, and OCP polycrystals formed in the mixture of β-TCP and ACP spheres. The OCP polycrystals gradually substituted for the ACP spheres without phase transformation of β-TCP into OCP.

Original languageEnglish
Pages (from-to)58-67
Number of pages10
JournalJournal of Crystal Growth
Volume332
Issue number1
DOIs
Publication statusPublished - Oct 1 2011

Fingerprint

calcium phosphates
Calcium phosphate
Precipitates
precipitates
phosphates
Phosphates
spherulites
phase transformations
Phase transitions
Polycrystals
polycrystals
Needles
needles
Single crystals
sea urchins
octacalcium phosphate
amorphous calcium phosphate
single crystals
blades
Dissolution

All Science Journal Classification (ASJC) codes

  • Condensed Matter Physics
  • Inorganic Chemistry
  • Materials Chemistry

Cite this

Morphological evolution of precipitates during transformation of amorphous calcium phosphate into octacalcium phosphate in relation to role of intermediate phase. / Sugiura, Yuki; Onuma, Kazuo; Kimura, Yuki; Miura, Hitoshi; Tsukamoto, Katsuo.

In: Journal of Crystal Growth, Vol. 332, No. 1, 01.10.2011, p. 58-67.

Research output: Contribution to journalArticle

Sugiura, Yuki ; Onuma, Kazuo ; Kimura, Yuki ; Miura, Hitoshi ; Tsukamoto, Katsuo. / Morphological evolution of precipitates during transformation of amorphous calcium phosphate into octacalcium phosphate in relation to role of intermediate phase. In: Journal of Crystal Growth. 2011 ; Vol. 332, No. 1. pp. 58-67.
@article{6fb9cd4e87dd460abafc307483c2eb18,
title = "Morphological evolution of precipitates during transformation of amorphous calcium phosphate into octacalcium phosphate in relation to role of intermediate phase",
abstract = "Nucleation of amorphous calcium phosphate (ACP) and its phase transformation with a decrease in solution pH were investigated at a constant temperature of 32 °C. A solution containing a mixture of CaCl2 and KH2PO4 was prepared (initial pH=7.7), and a drop was sampled at a constant interval to observe the morphological evolution of the precipitates that formed in the solution. A gel-like solution structure formed immediately after mixing and contained a small amount of sea-urchin-like ACP spherulites (320 μm in size). These spherulites consisted of 1.510-μm-long flexible needles that formed simultaneously with numerous ACP spherical particles. They first transformed into β-tri calcium phosphate-like material (called pseudo β-TCP) and then into single crystals of octacalcium phosphate (OCP) without dissolution. The flexible needles in the spherulites changed into blade springs, then into flexible plates, and finally into rigid plates during the transformation. The OCP structure appeared in the pseudo β-TCP plates and gradually substituted for the β-TCP structure over time. The macroscopic spherulite morphology of the initial ACP remained unchanged during the phase transformation, suggesting that OCP is a pseudomorph of ACP. This feature was observed only when the ACP spherulites formed in the initial solution. Fiber-like aggregates consisting of β-TCP single crystals nucleated around the ACP spherical particles and grew over time. They survived until the final stage of the reaction, and OCP polycrystals formed in the mixture of β-TCP and ACP spheres. The OCP polycrystals gradually substituted for the ACP spheres without phase transformation of β-TCP into OCP.",
author = "Yuki Sugiura and Kazuo Onuma and Yuki Kimura and Hitoshi Miura and Katsuo Tsukamoto",
year = "2011",
month = "10",
day = "1",
doi = "10.1016/j.jcrysgro.2011.07.030",
language = "English",
volume = "332",
pages = "58--67",
journal = "Journal of Crystal Growth",
issn = "0022-0248",
publisher = "Elsevier",
number = "1",

}

TY - JOUR

T1 - Morphological evolution of precipitates during transformation of amorphous calcium phosphate into octacalcium phosphate in relation to role of intermediate phase

AU - Sugiura, Yuki

AU - Onuma, Kazuo

AU - Kimura, Yuki

AU - Miura, Hitoshi

AU - Tsukamoto, Katsuo

PY - 2011/10/1

Y1 - 2011/10/1

N2 - Nucleation of amorphous calcium phosphate (ACP) and its phase transformation with a decrease in solution pH were investigated at a constant temperature of 32 °C. A solution containing a mixture of CaCl2 and KH2PO4 was prepared (initial pH=7.7), and a drop was sampled at a constant interval to observe the morphological evolution of the precipitates that formed in the solution. A gel-like solution structure formed immediately after mixing and contained a small amount of sea-urchin-like ACP spherulites (320 μm in size). These spherulites consisted of 1.510-μm-long flexible needles that formed simultaneously with numerous ACP spherical particles. They first transformed into β-tri calcium phosphate-like material (called pseudo β-TCP) and then into single crystals of octacalcium phosphate (OCP) without dissolution. The flexible needles in the spherulites changed into blade springs, then into flexible plates, and finally into rigid plates during the transformation. The OCP structure appeared in the pseudo β-TCP plates and gradually substituted for the β-TCP structure over time. The macroscopic spherulite morphology of the initial ACP remained unchanged during the phase transformation, suggesting that OCP is a pseudomorph of ACP. This feature was observed only when the ACP spherulites formed in the initial solution. Fiber-like aggregates consisting of β-TCP single crystals nucleated around the ACP spherical particles and grew over time. They survived until the final stage of the reaction, and OCP polycrystals formed in the mixture of β-TCP and ACP spheres. The OCP polycrystals gradually substituted for the ACP spheres without phase transformation of β-TCP into OCP.

AB - Nucleation of amorphous calcium phosphate (ACP) and its phase transformation with a decrease in solution pH were investigated at a constant temperature of 32 °C. A solution containing a mixture of CaCl2 and KH2PO4 was prepared (initial pH=7.7), and a drop was sampled at a constant interval to observe the morphological evolution of the precipitates that formed in the solution. A gel-like solution structure formed immediately after mixing and contained a small amount of sea-urchin-like ACP spherulites (320 μm in size). These spherulites consisted of 1.510-μm-long flexible needles that formed simultaneously with numerous ACP spherical particles. They first transformed into β-tri calcium phosphate-like material (called pseudo β-TCP) and then into single crystals of octacalcium phosphate (OCP) without dissolution. The flexible needles in the spherulites changed into blade springs, then into flexible plates, and finally into rigid plates during the transformation. The OCP structure appeared in the pseudo β-TCP plates and gradually substituted for the β-TCP structure over time. The macroscopic spherulite morphology of the initial ACP remained unchanged during the phase transformation, suggesting that OCP is a pseudomorph of ACP. This feature was observed only when the ACP spherulites formed in the initial solution. Fiber-like aggregates consisting of β-TCP single crystals nucleated around the ACP spherical particles and grew over time. They survived until the final stage of the reaction, and OCP polycrystals formed in the mixture of β-TCP and ACP spheres. The OCP polycrystals gradually substituted for the ACP spheres without phase transformation of β-TCP into OCP.

UR - http://www.scopus.com/inward/record.url?scp=80052317047&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=80052317047&partnerID=8YFLogxK

U2 - 10.1016/j.jcrysgro.2011.07.030

DO - 10.1016/j.jcrysgro.2011.07.030

M3 - Article

VL - 332

SP - 58

EP - 67

JO - Journal of Crystal Growth

JF - Journal of Crystal Growth

SN - 0022-0248

IS - 1

ER -