consisting of calcium and phosphoric alcoholates was synthesized from the reaction between. (C2H5O)3P in ethanol and calcium ethoxide which was prepared.
Phosphorus
Research
Bulletin
SYNTHESIS
OF
Vol. 5 (1995), 25-30
HYDROXYAPATITE
Kazuaki
BY
HASHIMOTO, Yoshitomo
Shigekazu
UDAGAWA
and
SOL-GEL
METHOD
TODA, Koji MIURA,
Takafumi
KANAZAWA*
Department of Industrial Chemistry, Chiba Institute of Technology, 2-17-1 Tsudanuma, Narashino-shi, Chiba 275, JAPAN. *Research Institute , Chiba Institute of Technology, 2-17-1 Tsudanuma, Narashino-shi, Chiba 275, JAPAN. Abstract Hydroxyapatite
(HAp)
reaction
of of the
which
hours.
and
The 1.67,
The
of
the
synthetic
was
alcoholates in
with
of
changed very
to
little
and
between were
temperature
method
the
25•Ž
HAp
starting
heating.
calcium-deficiency
gel
synthesized
calcium
ethoxide Ca Ca/P
aging
in
dried
metallic
and
by
The was
ethanol
reaction
conditions
finally
HAp
sol-gel
system.
(C2H5O)3P
from
synthetic
gel
synthesis
using
phosphoric
between
prepared
C2H4(OH)2. of
calcium
reaction
was
ratio
synthesized
Ca-C2H4(OH)2-(C2H5O)3P-C2H5OH
consisting from
was
and
atomic
time
above
We
succeeded
using
this
12 in
sol-gel
method.
I. INTRODUCTION Hydroxyapatite as biomaterials have
been
because
synthesized
hydrothermal
reaction
HAp by sol-gel been
(HAp) and related
favorable metallic
for
2) and wet
synthesis
In the present
October
superior
biological
as solid-state
reaction
including
the wet chemical
7-9),because
particles
and
3-6). The
of
These
reaction 1), synthesis reaction,
the sol-gel
coating
used
affinities.
chemical
researchers
of fine
such
have been
method
surfaces
of has is of
materials. paper,
(C2H5O)3P-C2H5OH system Received
especially
by several
or ceramic
have
phosphates
using the methods
method,
investigated
these
calcium
24, 1995; Accepted
the sol-gel in order November
method
in reaction
to synthesize 24, 1995
-25-
of Ca-C2H4(OH)2-
the fine particles
of HAp
without
calcium-deficiency
synthetic
conditions
has been
investigated
in detail
such as Ca/P ratio, temperature
with respect
to
and aging time.
II. EXPERIMENTAL
2.1 Synthetic The in
procedure
dried
reaction
of
(0.01mol) to
atomic added
kept
at
(C2H5O)3P
to
500•`1300•Ž study,
we
the
for
1
used
hour
their
product
glycol,
change
(Macsience,TG-DTA2020).
were 10A
the
of
the
: calcium,
adjusting
the starting
and
product
solution
was
washed
with
was
heated
particles.
which
carried
out
at
In
were
ion
the
diffractometer was
this
distilled
the
above-
of
product
AND
character
Ca/P atomic
using was
The
chromatography blue
(Rigaku,RINT-
evaluated
(Hitachi,H-9000).
molybdenum
we examined
HAp
ethanol
X-ray
morphology
III.RESULTS
First,
and
gel
Ca/P
(0.02•`0.10mol)
was
dried to
points,
an
microscope
); phosphorus,
changed
(C2H5O)3P
using
The
following
SYSTEM
was
The
starting
mixed sol
was
products
identified
electron
The
Ca
solution
the
H2O
obtained
metallic
this
Further,
method
N2 atmosphere.
of
thermal
and
gelation.
sol-gel
First,
adjusted
lyophilized.
boiling
under
was
The
and
respective
was
for
hours.
air,
by
(0.5mol),
(10cm3).
and in
Characterization
transmission
prepared system.
which
solution
ethylene
reaction
The
was
glycol
ethanol
1•`48
centrifuged
mentioned
1500).
mixed
was
to
The
HAp
ethylene
in
for
according
2.2
in
0.5•`2.0
into
and
of
(0.005•`0.02mol)
25•`60•Ž
ethanol,
precursor
dissolved
ratios
was
as
method
Ca-C2H4(OH)2-(C2H5O)3P-C2H5OH
was
mixed
gel
of sol-gel
observed
chemical
analysis colorimetric
by
a
analyses
(Shimadzu,
LC-
analysis.
DISCUSSION
of the
dried
gels synthesized
ratio from 0.5 to 2.0. The X-ray
-26-
a TG-DTA
by
Fig.1 X-Ray diffraction dried gels. 25℃ Synthetic temp.: Aging time :48h Amount of H2O : 0.10 diffraction
patterns
conditions
are
were
very
refer
to
results gels
the of
chemical
differed
and
affected the dried the
product
the X-ray
gels
the
structure
depended of
on the
1000•Ž.
a
atomic
mixture
which
the
under
the
heating
of the
the
dried
1h.
starting the
phase ratio
of ƒÀ-CPP
Ca/P
atomic
ratio
=1.0,
and
Ca/P
atomic
ratio
=1.5.
Only
was when
the of
=
atomic
obtained
of
ratio. by
ratio
of
Such
a result
was ƒÀ-Ca2P2O7
a mixture the
of ƒÀ-TCP starting
-27-
Ca/P
the
by
and atomic
HAp
the
obtained directly 2
shows
heating gel
(ƒÀ-CPP).
(ƒÀ-TCP)
peak
From
Figure
the
gels
weak
similar.
heated
and ƒÀ-Ca3(PO4)2
dried
all
obtained
product
the and
heating.
products
the
0.5
were
atomic
synthetic
of
a broad
and Ca/P
Ca/P
various
patterns
indicated
degree,
products
The
was
for
diffraction
2Į = 5.8
analysis,
at
Ca/P
patterns
by
at 1000•Ž
obtained
1. The
at
patterns
starting
gels
patterns,
diffraction
gels
diffraction
obtained
mol
in Figure
phase
X-Ray
products
crystalline gel
of the Fig.2
of
shown
low
patterns
in
the case
Further,
in in ratio
case case was
of the
of
the
of
the 1.67,
the
single-phase The
effect
shown the
in
of
Figure
3.
synthetic
Ca/P
however,
it
hours
or
Ca/P
atomic
the
by
Fig.3 Ca/P
the
The
dried
the
gels
of
is
their
gels
faster
did
we
added
became
ca.
of
The
The
Ca/P
became
1.82;
agitated
approximated
the the
of
=1.67.
time.
were
that
that
ratio
hour
gels
is
for theoretical
hydrolysis
phosphoric
12
rate
alcoholate
of and
hours.
additional occur
1.66
1
product
conditions
aging
for
considered
for
not
atomic
the
the
the
with
aging
to
of
under Ca/P
When
than 12
ratio
changed by
required
an
the
was
we
after
H2O
and
down
Thus,
atomic prepared
time.
came
much
when gels
dried
aging
changing reaction
25•Ž
with
reached of
of
obtained
HAp.
Ca/P
were
gels
it
is
occurred of
on
further, ratio
gelation
ratios
time
decreased
amount
readily
aging
the
equilibrium
The
synthesized.
of
alcoholate
prepared
be
of
above,
The
could
ratio
ratio
calcium
HAp
temperature
atomic
atomic
it
of
gelation
was
amount
of
when
we
regardless
The effect of aging time on the atomic ratio of the dried gels.
temp.: 25 ℃ Ca/P ratio :1.67 Amount of H2O : 0.10 mol Synthetic
Fig.4 dried
H2O
added
0.04•`0.10
1.67
examined.
The gels
The
from
0
0•`0.02 H2O.
of
amount
products prepared
All
of
various
temperatures. Heating
-28-
conditions
: 1000•Ž,1h
mole.
H2O,
Ca/P
obtained at
were
0.10
molar
molar the
to
gels
but
atomic
H2O.
by
heating
synthetic
the
Fig.5 Thermal changes of the dried Synthetic temp.: 2 5℃
Ca/P ratio Aging time In
to
gels
As
shows
shown
in
by
the
and
the the
40•Ž
considered at
heating teinperature.
around it
this
above
500•Ž We
gel
were
the
dried
at
single-phase
we
heated
temperatures.
HAp was
the
synthetic
when
synthetic of
on
various
products
various
precursor
decreased not
with
produced
at
precursor
of
above. change
of
dried
gel
peak
was
50% near this peak
combustion temperature. and
the
exothermic
of about
not
temperature
gels the
at
as or
synthetic
shows
as
a high
that
of
prepared
thermal
Figure,
effect
4
HAp
was weight loss
We
occurred
heating
of
of
5
there
66.7%).
HAp
been
temperatures
℃ and
gel
had
region
Figure
of
Figure
temperature,
synthetic
HAp.
prepared
25-60•Ž.
which
formation
synthetic
the
we of
dried
The
investigate
further,
temperatures the
:1.67 :48h
order
product,
Fig.6 The relationship between the lattice constant of HAp and heating temperature .
gels.
the able
-29-
of
organic
The
dried
crystallinity to
observe
as
observed
at
(final weight loss
components gel of
the
216
was
HAp formation
in
the
changed
increased
to with
of ƒÀ-TCP
Fig.7
TEM
photographs
the
in
HAp
dried
obtained ratio
of
atomic
ratio
of with
The
TEM
obtained a
the
by
HAp.
1.66
As
heating
gels(A) 1h
the
was
shown
and
the
products
obtained
by
heating
(B).
dried
gel
which
approximated
in
at
Figure
1000•Ž
6,
because a
the
lattice
the
Ca/P
theoretical
Ca/P
constant
of
HAp
temperature. of the
shape.
it was
for
heating
HAp
heating
dried
1000•Ž
photographs
feather-like
heating
at
by
atomic
decreased
of
gels
dried
On
granular
the
dried
gel
the
are
hand,
and
as
shown
other
crystals
gel
the
precursor
of
in Figure the
particle
7.
The
shape
of
HAp
sizes
were
HAp
and
dried
gel
HAp had
obtained
100•`200nm.
REFERENCES 1) H. Monma, 2) K. Ioku,
T. Kanazawa, M. Yoshimura,
3) H. Monma, 4) Y. Suwa,
S. Ueno, H. Banno,
M. Mizuno,
A. Kishioka,
6) K. Hashimoto,
Y. Toda,
2 (No.254),
8) Y. Kojima,
Soc. Jpn.,
1972,
J. Chem.
M. Tsutsumi,
5) M. Kinoshita,
7) Y. Masuda,
J. Chem. S. Somiya,
T. Kanazawa, H. Saito,
K. Fujita,
K. Itatani,
T. Mogi,
1565(1988).
Soc. Jpn., Sekko
S. Udagawa,
to
88,
101,
659(1993).
Sekkai,
Inorganic
590(1978).
No.219,
23(1989).
Materials,
3(1995). K. Matsubara, A. Shiraishi,
S. Sakka, K. Ishii,
J. Ceram.
T. Yasue,
Y. Arai,
Soc. Jpn., Phosphorus
3,79(1993). 9) T. Tsuchiya,
1988,
Yogyo-kyokai-shi.,
J. Ceram.
H. Hayashi,
339(1972).
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by
