TITLE:
Preparation of High Percentage α-Calcium Sulfate Hemihydrate via a Hydrothermal Method
AUTHORS:
Le Fu, Wei Xia, Torbjörn Mellgren, Mikael Moge, Håkan Engqvist
KEYWORDS:
α-Calcium Sulfate Hemihydrate, High Percentage, Hydrothermal Method, Calcium Sulfate Dihydrate Cement
JOURNAL NAME:
Journal of Biomaterials and Nanobiotechnology,
Vol.8 No.1,
January
4,
2017
ABSTRACT: α-calcium sulfate hemihydrate (α-HH) is known to be suitable for application as bone void filler.
High percentage of α-HH is obviously
needed for medical applications, especially for implantation. Three commercially
available calcium sulfate dihydrates (DH, CaSO4·2H2O) with different sizes and
surface morphologies were used as starting materials to synthesize high
percentage α-HH via a hydrothermal
method. The median particle sizes of the three types of DH were 946.7 μm, 162.4 μm and 62.4 μm, respectively. They were named as DH-L, DH-M and DH-S in this paper. The particle size
distribution, morphology and phase composition of the raw materials were evaluated
before synthesis. SEM results revealed that DH-L consisted of irregular large particles,
while DH-M and DH-S were composed of plate-like particles
with some small ones. High percentage HH can be obtained with proper synthesis parameters by hydrothermal
method, specifically, 105 °C/90 min for DH-L (achieving
98.8% HH), 105°C/30 min for DH-M
(achieving 96.7% HH) and 100°C/45
min for DH-S (achieving 98.4% HH). All the synthesized HH were hexagonal columns, demonstrating that they were α-phase HH. The particle size and morphology of starting material
(DH) have significant influences on not only the rate of phase transition but
also the morphology of the synthesized α-HH.
Calcium sulfate dihydrate cements were prepared by the synthesized α-HH. The highest compressive strength
of calcium sulfate dihydrate cement was 17.2 MPa. The results show that the preparation
of high percentage α-HH is feasible
via a hydrothermal method and the process can be further scaled up to industrial
scale production.