Direct synthesis of nanocrystalline hydroxyapatite by hydrothermal hydrolysis of alkylphosphates

Direct synthesis of nanocrystalline hydroxyapatite by hydrothermal hydrolysis of alkylphosphates

Peer-reviewed article not indexed in WoS or Scopus

The influence of reaction conditions (temperature, type of catalyst, time) on the base-catalyzed reaction of mono-, di-, and trialkylphosphates (alkyl=methyl, ethyl, i-propyl, n-butyl) with Ca2+ ions and on the structure and composition of the reaction products was studied. The composition of the calcium phosphates depends mainly on the reaction temperature. At temperatures below 100 degC, a nanocrystalline solid products transforming into dicalcium phosphate by heating (calcination) was found.Pure nanocrystalline hydroxyapatite was prepared by hydrothermal synthesis at 160 degC from mono- and dialkylphosphates. The size of hydroxyapatite crystallites was about 1 nm, the particle size about 150 um. Agglomerated particles of hydroxyapatite larger than 2 um were prepared at 200 degC. Hydrothermal reaction of trialkylphosphates with Ca2+ ions at 200 degC produced CaHPO4. The experimental results were used to propose a reaction mechanism for base-catalyzed hydrothermal reactions of alkylphosphates with Ca2+ ions.

The influence of reaction conditions (temperature, type of catalyst, time) on the base-catalyzed reaction of mono-, di-, and trialkylphosphates (alkyl=methyl, ethyl, i-propyl, n-butyl) with Ca2+ ions and on the structure and composition of the reaction products was studied. The composition of the calcium phosphates depends mainly on the reaction temperature. At temperatures below 100 degC, a nanocrystalline solid products transforming into dicalcium phosphate by heating (calcination) was found.Pure nanocrystalline hydroxyapatite was prepared by hydrothermal synthesis at 160 degC from mono- and dialkylphosphates. The size of hydroxyapatite crystallites was about 1 nm, the particle size about 150 um. Agglomerated particles of hydroxyapatite larger than 2 um were prepared at 200 degC. Hydrothermal reaction of trialkylphosphates with Ca2+ ions at 200 degC produced CaHPO4. The experimental results were used to propose a reaction mechanism for base-catalyzed hydrothermal reactions of alkylphosphates with Ca2+ ions.

ceramics, synthesis, nanostructures, hydroxyapatite, hydrothermal synthesis, alkylphosphates

ceramics, synthesis, nanostructures, hydroxyapatite, hydrothermal synthesis, alkylphosphates

CIHLÁŘ, J.; ČÁSTKOVÁ, K.

2011

01.01.2002

0026-9247

MONATSHEFTE FUR CHEMIE

133

6

Republic of Austria

761

11