Transcript Slide 1

IMNR
New hybrid inorganic-organic nanomaterials
obtained in hydrothermal conditions for
regenerative medicine
Roxana M. Piticescu,
National R&D Institute for Non-ferrous and Rare Metals
102 Biruintei Blvd., Pantelimon, Ilfov, Romania
Functional Nanomaterials II-05.09.2007
PRESENTATION CONTENT
Introduction
Materials chemistry, synthesis methods for nanostructured
materials
Original results
Hybrid organic-inorganic compounds
Conclusions
Acknowledgement
Functional Nanomaterials II-05.09.2007
Introduction
Materials research involves two main domains of activity [1]:
Synthesis of novel materials for improving basic knowledge, making
correlations between composition, chemical bonding, structure and
resulting physical properties
New routes for producing materials
economically cheaper processes
by
the
development
of
The optimization of the shape of materials (nano crystallites, thin
films, single crystals…) for specific applications
[1] G. Demazeau, G. Goglio, A. Largeteau, Solvothermal processes in Materials Synthesis, Mater. Res.
Soc. Symp. Proc. Vol. 878E, 2005
Functional Nanomaterials II-05.09.2007
Introduction
What we know from the literature data:
1.Hybrid materials synthesis routes: copolymerisation of organosilanes and metal
alkoxides, encapsulation of organic components within sol-gel derived silica or
metallic oxides, organic functionalisation of nanofillers, nanoclays or other
compounds with lamellar structures
2. Strong chemical bonding between organic-inorganic phases enhance the
mechanical properties of nanocomposites
3. Sol gel process drawbacks (large volume shrinkage due to the evaporation of large
amount of solvent, small molecular hydrolysis by-products and poly-condensation
reactions) limit its technological applications,
4. Fabrication ZnO nanostructured films and nanorods (diameter 90 nm, 1 micron
lengths ) by CVD, PLD, electrodeposition, template methods presents some
limitations to achieve a certain thickness and is incovenient for dopping when more
dopants are used. ZnO-PVA was used due to well distributed ligand radicals on chain
and the polymer chain limits the growth scale of ZnO core [5].
5. Fabrication of ZnO nanoparticles by thermooxidative degradation of ZnO
complexes e.g.:[Zn(phen)2(H2O)2][Zn(phen)S2O3)2].4H2O [6]
[1]. Cuiming Wu &al, European Polymer Journal, 41, 1901-1908, (2005)
[2]. Clement Sanchez &al, J.Mater.Chem.,
15, 3559-3592 (2005)
[3]. Eduardo Ruiz-Hitzky &al, J.Mater.Chem., 15, 3650-3662 (2005)
[4]. Jui-Ming Yeh &al, Journal of Applied Polymer Science, 101, 1151-1159 (2006)
[5].Ying He &all, J. Nanoparticles Res. 7, 307-310 (2005)
[6]. A. Dumbrava&al., J. Therm. Analysis& Calorim., 79, 509-514 (2005)
Functional Nanomaterials II-05.09.2007
Introduction
Methods for the preparation of nanostructured compounds
Conventional
methods
Form-in-place
processes
Gas phase synthesis
methods
Wet chemical methods
(“soft chemistry”)
Mechanical
methods
Physical vapor Laser ablation
deposition
(PVD)
Hydrothermal and
solvothermal synthesis
Solid-state
synthesis
Chemical
vapor
deposition
(CVD)
Microwave plasma
synthesis
Sol-gel method
Spray
pyrolysis
Vaporization-Condensation
(VC)
using Solar Physical Vapor
Deposition (SPVD)
Pechini method
The reactivity of the precursors play an important role in the preparation
of novel materials
Mild thermodynamic conditions (in terms of pressure and temperature
parameters) specific to hydrothermal or solvothermal reactions are able
to initiate through chemical bounding directly from solutions new nanostructures
Functional Nanomaterials II-05.09.2007
Introduction
Previous original
experimental works
Hydrothermal synthesis of
nanostructured oxides, hybrids
organic-inorganic
New
Nanostructured
compounds
Application
in the field of
Nanomedicine
Application
in the field of
Nanoelectronics
Application
in the field of Functionally
graded materials
Functional Nanomaterials II-05.09.2007
ORIGINAL RESULTS
The main goal is to prepare original nanostructured compounds:
hybrid organic/inorganic powders using hydrothermal method in
mild conditions.
The stabilization of hybrid organic/inorganic materials is favored by
low temperature and high pressure values.
Pressure can be the autogenous pressure (the vapor pressure of
components in solution) or a higher pressure due to the barbotage
of an inert gas before heating.
Some examples of hybrid organic/inorganic nanostructured
compounds are presented :
Hydroxyapatite/collagen nanocomposites
Hybrid nanostructures based on hydroxyapatite/maleic acid copolymers
Hybrid nanostructures based on hydroxyapatite/layered silicate
Hybrid nanostructures based on ZnO/maleic acid copolymers
Functional Nanomaterials II-05.09.2007
SWOT analysis of hydrothermal synthesis
S (STRENGTH) - O (OPORTUNITIES)
The ability to create crystalline phases which are not stable at the melting point
Materials which have a high vapor pressure near their melting points can be grown by a high
pressure method
Suitable for the growth of large good-quality crystals while maintaining good control over their
composition
Rapid nanoparticles production, morphology control with a little change of temperature or pressure,
control of oxidation state by introducing oxygen or hydrogen gas
By introducing organic substances including biomolecules in a reaction atmosphere of supercritical
hydrothermal / solvothermal synthesis, nanoparticles whose surface is modified with organic
materials can be synthesized. In supercritical state, water and organic materials form a
homogeneous phase, which provides an excellent reaction atmosphere for the organic modification
of nanoparticles
Modification with bio-materials including amino acids is also possible. By changing organic
modifiers, particle morphology and crystal structure can be changed. This organic surface
modification provides a various unique characteristics for the nanoparticles; possibility to form
strength chemical bonding under high pressures conditions between organic-inorganic phases
Dispersion of nanoparticles in aqueous solutions, organic solvents or in liquid polymers can be
controlled by selecting hydrophilic or hydrophobic modifiers
W (WEAKS) – T (THREATS)
Lack of thermodynamic and kinetic data
Very fine powders require high special compacting procedures
Functional Nanomaterials II-05.09.2007
Hydrothermal synthesis of nanostructured compounds
Inorganic salt
solution
Solution of
doping element
Mineralising agent
Polymer
Hydrothermal
synthesis
Washing/Filtering
Mother liquor/Washing waters
Wet powders
Chemical analysis
UV-VIS,
ICP,
AAS
Structural characterisation
XRD, DSC,
FT-IR, HRTEM
Nanocrystalline powders
Functional Nanomaterials II-05.09.2007
Original results
Hydroxyapatite/collagen nanocomposites
FT-IR spectra for HAp-collagen nanopowders
HAP+20% collagen
60
HAP+30% collagen
HAP+40% collagen
50
%T
40
3
30
3
20
10
2
4 5
6
4 56
78
1 2
0
4000
3500
9
12
9
12
10
3000
2500
2000
1500
1000
11
500
-1
Wavenumber [cm ]
FT-IR analysis of HAp/COL nanocomposites shows the specific bands of
hydroxyapatite as well as the presence of collagen with its characteristic functional
groups [2].
[2] L.M. Popescu, A. Meghea, R.M. Piticescu, E.Vasile, High pressure synthesis procedure to obtained
nanostructured composites for regenerative medicine, submitted to Journal of Optoelectronics and
Advanced Materials.
Functional Nanomaterials II-05.09.2007
Original results
Hydroxyapatite/collagen nanocomposites
Hydroxyapatite-collagen hybrid powder consists of
particles with spherical or polyhedral shape, grouped in
small chains and measuring nearly 4-7 nm in diameter
[2].
TEM image
of one
representative
sample
(scale 100 nm)
[2] L.M. Popescu, A.
Meghea, R.M. Piticescu,
E.Vasile, High pressure
synthesis procedure to
obtained nanostructured
composites for
regenerative medicine,
submitted to Journal of
Optoelectronics and
Advanced Materials.
Nanocrystalline
HAp
Functional Nanomaterials II-05.09.2007
Original results
Hybrid nanostructures based on
hydroxyapatite/layered silicate
40
BVCUAP-purified montmorillonite
HBP 4
30
T [%]
1992
20
3571
3224
10
1641
3434
3631
3451
1411
3635
0
4500
894
1035
4000
3500
3000
2500
2000
-1
1500
1000
Wavenumber
[cm 2007(In
]
Roxana Piticescu&al., J. Liquid&Molecular
Crystals
press)
Functional Nanomaterials II-05.09.2007
500
Original results
Hybrid nanostructures based on
hydroxyapatite/layered silicate
Bright field transmission micrograph
of sample HBP2
HRTEM micrograph
of sample HBP2
Roxana Piticescu&al., J. Liquid&Molecular Crystals 2007(In press)
Functional Nanomaterials II-05.09.2007
Original results
Some preliminary biocompatibility tests
TiNb/P1HA6S1
TiNb/P1HA6S
1
SA
TiNb/P1HA6S2
TiNb/P1HA6S3
SA
TiNb/P1HA6S3
TiNb/P1HA6S2
SNA
SNA
SA
SA
SA
SA
SNA
Citotoxicity tests for TiAlNb alloys coated by spin coating procedure with
Phosphorilated polissacharide-Hap nanostructured hybrids
SNA
Biocompatibility evaluation of a novel hydroxyapatite-polymer coating for medical implants (in vitro tests)
G.Negroiu, L. Zdrentu R.M. Piticescu ,G. C. Chitanu , I.N. Mihailescu
Accepted for publication in J.Materials Science: Materials in Medicine
SA
Functional Nanomaterials II-05.09.2007
SA
Original results
Hybrid nanostructures based on ZnO/maleic acid
copolymer
500
400
300
200
d
ifie
ent
nid
o
N
100
d
ifie
ent
nid
No
0
20
30
40
50
2Theta (deg)
File: ZnO - AM222.raw
Zn(OH)2 - Zinc Hydroxide - 01-074-0094 (I)
ZnO - Zinc Oxide - 01-089-1397 (*)
Functional Nanomaterials II-05.09.2007
60
70
Original results
New types of binary systems
Ca10(PO4)6 (OH)2
d ln p 
H
dT
RT 2
A possible explanation of
interactions between natural
silicate and HAP
Formation of nanocrystalline
solid species is favored under
hydrothermal conditions
Vg > > Vl
Functional Nanomaterials II-05.09.2007
Conclusions
New binary systems based on hydroxyl apatite- purified montmorillonite were synthesized in situ in hydrothermal conditions at high pressures and
low temperatures. The process enables the formation of complex
nanostructured materials with controlled phase composition.
The possibility to form chemical bonding between phases was revealed
by different methods: XRD, FT-IR
Microstructure and morphology investigation by HRTEM shows the
presence of both hydroxyl apatite with rod-like shapes of lengths up to
100 nm and montmorillonite forming a complex nanostructured material.
Further works are in course to detail the mechanisms of formation of the
new binary systems.
Further works are in course to analyse and characterise some binary
systems synthesised in hydrothermal conditions at very high pressures
(3000, 4000, and 7000 bars respectively) at Université de BORDEAUX 1-
Centre de Ressources Hautes Pressions (experiments performed in the
frame of COST D30 action).
Functional Nanomaterials II-05.09.2007
Conclusions
Performed multidisciplinary works try to answer to the ETP
Nanomedicine questions:
-What are the best materials to be used in regenerative medicine;
-What are the appropriate cellular lines ;
-Do we need new materials/new technologies;
- What is the level of the research in the field of regenerative
medicine: basic research and applicative research.
Functional Nanomaterials II-05.09.2007
Aknowledgement
This paper is a result of experimental works performed in the
frame of Research for Excellence contracts 46-ReteBdent, 69SINAPS and 16-TECOREMED financed by Romanian Agency for
Scientific Research and COST D30 – High pressure Tuning of
Materials.
The authors thank:
Prof. Gerard Demazeau - Univ.Bordeaux for fruitfull disscusions
Dr.Maria Giurginca - CNC-UPB for performing FT-IR spectra of
composites,
Dr. Zina Vuluga – ICECHIM for providing natural purified
montmorillonite
Dr. Gabrielle Chitanu – ICMPP for providing synthetic polymers.
Dr. Gabriela Negroiu – Biochemistry Institute, Bucharest,
Romanian Academy-for in vitro tests.
Functional Nanomaterials II-05.09.2007
Thank you for your attention !
Functional Nanomaterials II-05.09.2007