VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali
ELECTROSPUN NANOHYBRID
MEMBRANES BASED ON BIORESORBABLE
POLYMER AND CARBON NANOSTRUCTURESIlaria Armentano, Alessandra Bianco, Costantino Del
Gaudio, Mariaserena Dottori, Francesca Nanni, Josè Maria Kenny.
Materials Engineering Centre, UdR INSTM, NIPLAB, University of Perugia, Terni,
Dip. di Scienze e Tecnologie Chimiche, Università di Roma Tor Vergata, Via della Ricerca Scientifica, Roma, 00133 (M) -
ITALY
VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali
AimAim
The purpose of this study was to investigate nanohybrid systems based on bioresorbable Polymers and CNSs, in different Morphological structures.
CompositionMorphology
VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali
Outline
State of the artMaterials & Methods
Nanocomposite Development: Membranes & Film
Nanocomposite Charaterization: Morphological & Thermal & Dynamo-
MechanicalConclusions
VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali
Bioresorbable PolymersBioresorbable Polymers
NANOCOMPOSITE
O CH2 C
O
n
PGA
O CH
CH3
C
O
n
PLA
O CH2 C
O
n
PCL
PLA-PGA
PLA-PCL
•Chen G-X, Kim H-S, Park BH, Yoon J-S. Controlled Functionalization of Multiwalled Carbon Nanotubes with Various Molecular-Weight Poly(L-lactic acid)., J Phys Chem B 2005;109:22237-22243.• Zhongkui Honga, Xueyu Qiua, Jingru Suna, Mingxiao Denga, Xuesi Chena,b,*, Xiabin Jinga Grafting polymerization of L-lactide on the surface of hydroxyapatite nano-crystals, Polymer 45 (2004) 6699–6706
VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali
Carbon Nanotubes Carbon Nanotubes tubes made of a single sheet of graphene (SingleWallNanoTube)or more sheets (MultiWallNanoTube)
The regular geometry gives CNT excellent
mechanical and electrical
properties.
CNT diameters are in the range 1 - 500 nm; CNT lengths can range from several µm to mm.Richard Smalley: “These nanotubes are so beautiful that they must
be useful for something.”
VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali
CNTsCNTs Why CNTs? Extraordinary properties
Structure Nano and um dimensions High aspect ratio: 1000 High specific surface area: 1400m2/g High ratio interfacial area/vol: 1000 um-1
Large number density/vol: 106 CNTs/um3
Size scale comparable to interface layer (1-10 nm)
Chirality based on rolling direction Found as single wall and Multi wall tubes
Unique Structure
VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali
Mechanical Properties
SWNTs: 0.32-1.47 TPa (100 x steel) 0.5-5.5 TPa SWNTs Bundles: 230 Gpa
Young’s modulus
CNTs Fibres
Light, strong and highly flexible material
Vigolo B,Pe エ nicaud A,Coulon C,Sauder C,Pailler R,Journet C al.Macroscopic .bers and ribbons of oriented carbon nanotubes.Science 2000;290:1331.
*C.A. Dyke and J.M. Tour. Covalent Functionalization of Single-Walled Carbon Nanotubes for Materials Applications. The Journal of Physical Chemistry, 2004.
VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali
ElectroSpinningElectroSpinning
A typical electrospinning set-up using a grounded static collector.
Nanotechnology 17 (2006) R89–R106 WETeo and S Ramakrishna
Nanofibres
> 5 kV
Experimental conditions:
•Solution viscosity
•Molecular weight
•Voltage
•Solvent
Fibres Diameter
DCThe formation of nanofibres through electrospinning is based on the uniaxial stretching of a viscoelastic solution.
A high voltage is applied to the solution such that at a critical voltage, typically more than 5 kV, the repulsive force within the charged solution is larger than its surface tension and a jet would erupt from the tip of the spinneret.
VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali
Materials
ε-PCL
Sigma AldrichSigma Aldrich
Polymer Matrix
MethodsSolvent
Casting in CHCl3
CNFs: Carbon NanoFibers, Pyrograf
SWNTs: Single Wall Carbon Single Wall Carbon Nanotubes, Thomas Swan Nanotubes, Thomas Swan & Co.Ltd.
Electrospinning
CNSs
Flat Film d=200
µm
Porous Membranes
1 % wtO CH2 C
O
n
•Chen G-X, Kim H-S, Park BH, Yoon J-S. Controlled Functionalization of Multiwalled Carbon Nanotubes with Various Molecular-Weight Poly(L-lactic acid)., J Phys Chem B 2005;109:22237-22243.• Zhongkui Honga, Xueyu Qiua, Jingru Suna, Mingxiao Denga, Xuesi Chena,b,*, Xiabin Jinga Grafting polymerization of L-lactide on the surface of hydroxyapatite nano-crystals, Polymer 45 (2004) 6699–6706
&
MW 80000
VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali
SWNTs
0 100 200 300 400 500 600 700 800 900
0
20
40
60
80
100
Air
T [°C]
Re
sid
ua
l Ma
ss [
%]
0.00
0.02
0.04
0.06
0.08
0.10
0.12
DT
G [g
/g m
in]
FESEM - Zeiss Supra25Seiko exstar 6000
T=555°C Residual Mass=3% Metal catalist
PURITY
TGAIn Air 5°C/min (30-1000)°C
TG and derivative oxidation thermograms of pristine SWNTs
SEM image of the specimen of pristine SWNTs cross linked bundles
VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali
CNFsCarbon Nanofibers
0 200 400 600 800 1000 1200
0
20
40
60
80
100890 °C
0.6%
CNFs
T [°C]
Res
idua
l Mas
s [%
]
-0.01
0.00
0.01
0.02
0.03
0.04
0.05
0.06
DT
G
TGAIn Air 5°C/min (30-1000)°C
FESEM - Zeiss Supra25Seiko exstar 6000
VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali
Morphological AnalysisMorphological AnalysisField Emission Scanning Electron Microscopy FESEM-Supra 25 Zeiss
PCL Membranes
VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali
CONTACT ANGLEFTA 1000 AnalyserSurface Characterization
(118± 1)°
PCL Membranes PCL Film
hydrophobic surface
Water
(74.5± 0.5)°
Materials Water Contact Angle
PCL (74.5± 0.5)°
PCL+1%SWNTs
(74.2± 0.5)°
VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali
Morphological AnalysisMorphological AnalysisField Emission Scanning Electron Microscopy FESEM-Supra 25 Zeiss
Film, fracture surface PCL+ CNFs 1% wt
VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali
Morphological AnalysisMorphological AnalysisField Emission Scanning Electron Microscopy FESEM-Supra 25 Zeiss
Film, fracture surface PCL+ SWNTs 1% wt
VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali
Morphological AnalysisMorphological AnalysisField Emission Scanning Electron Microscopy FESEM-Supra 25 Zeiss
Nanohybrid Membranes PCL+ CNFs 1% wt
Surface
VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali
Morphological AnalysisMorphological AnalysisField Emission Scanning Electron Microscopy FESEM-Supra 25 Zeiss
Nanohybrid Membranes PCL+ CNFs 1% wt
Cross Section
VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali
Morphological AnalysisMorphological AnalysisField Emission Scanning Electron Microscopy FESEM-Supra 25 Zeiss
Nanohybrid Membranes PCL+ SWNTs 1% wt
Surface
VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali
Dielectric Dielectric CharacterizationCharacterization
101
102
103
104
105
106
1E-9
1E-8
1E-7
1E-6
1E-5
1E-4
AC [
S/m
]
[Hz]
PCL PCL SWNTs 0,1% PCL SWNTs 0,75% PCL SWNTs 1%
HP4284 20 Hz-1MHz
A
d
Z
1
Specific bulk AC conductivity and dielectric constant as a function of frequency for PCL based nanocomposite films with different nanofiller content.
Characterization of conductivity of CNSs/polymer materials:
An introduction of carbon nanotubes in the polymer matrix is expected to influence the strength and the electrical conductivity of the nanocomposite.
Cu
CuPCL Nanocomposite
VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali
Thermal CharacterizationThermal CharacterizationDSC
The samples were heated from -25 to 100°C at a scanning rate of 10°C/min. Two heating cycles were performed. The first heating cycle was used to remove all thermal history.
Mettler Toledo 822 DSC
Film
-20 0 20 40 60 80 100
30
40
50
60
70
80 I Cycle
Flo
w R
ate
[mW
]
Temperatura [°C]
PCL film PCL CNFs 0.5% PCL CNFs 1% PCL SWNTs 1%
-20 0 20 40 60 80 100
10
20
30
40
50
60
70II Cycle
Flo
w R
ate
[mW
]
Temperatura [°C]
PCL film PCL CNFs 0.5% PCL CNFs 1% PCL SWNTs 1%
PCL + CNSs
VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali
Thermal CharacterizationThermal Characterization
-20 0 20 40 60 80 100
10
20
30
40
50
60
II Cycle
Flo
w R
ate
(mW
)
Temperatura (°C)
PCL PCL CNFs 0,5% PCL CNFs 1% PCL SWNTs 1%
DSC
The samples were heated from -25 to 100°C at a scanning rate of 10°C/min. Two heating cycles were performed. The first heating cycle was used to remove all thermal history.
Mettler Toledo 822 DSC
Membranes
-40 -20 0 20 40 60 80 10015
20
25
30
35
40
45
50
55
60 I Cycle
Flo
w R
ate
[mW
]
Temperature [°C]
PCL PCL CNFs 0,5% PCL CNFs 1% PCL SWNTs 1%
PCL + CNSs
VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali
Thermal CharacterizationThermal Characterization
Xc(%)=ΔH/ΔH0 ΔH0 = 136 J/g
Polymer 41 (2000) 9073–9080
MaterialsΔHm1(J/
g)ΔHc(J/
g)ΔHm2(J/
g)Tm1(°C) Tc(°C) Tm2 (°C) Xc1(%) Xc2(%)
PCL pelletsPCL pellets 57,1± 0,9 46,0± 0,5 40,6± 0,6 58,7± 0,3 17,8 ± 0,7 56,0± 0,9 42,0± 0,529,9±
0,4
PCL filmPCL film 67 ± 2 49 ± 1 39,8 ± 0,861,61 ±
0,0122.7 ± 0,2
56,34 ± 0,08
50 ± 130.2 ±
0,6
PCL SWNTs PCL SWNTs 1% wt1% wt
60 ± 1 46 ± 1 42,6 ± 0,8 58,6 ± 0,2 32,1 ± 0,1 55,5 ± 0,244,5 ±
0,7 31,3 ±
0,6
PCL CNFs PCL CNFs 1% wt1% wt
56,8 ± 0,1 46,1 ± 0,3
39,6 ± 0,3 58,9 ± 0,2 29,88 ± 0,09
55,6 ± 0,3 41,8 ± 0,1
29,1 ± 0,2
SC_PCL SC_PCL 68,5 ± 0,9 55 ± 1 45 ± 1 57,7 ± 0,1 24,59 ± 0.01
55,6 ± 0,2 50 ± 1 33,1± 0,7
SC_PCL SC_PCL CNFs 1% wtCNFs 1% wt
57,7 ± 0,3 49,7± 0,3 43,1 ± 0,8 57,5 ± 0,3 32,6 ± 0,2 55,9 ± 0,4 42,4 ± 0,2
31,7 ± 0,6
SC_PCL SC_PCL SWNTs 1% SWNTs 1%
56,1 ± 0,2 51,0 ± 0,6
44 ± 2 57,7 ± 0,3 33,97 ± 0,09
56,1 ± 0,3 41,3 ± 0,2
32 ± 1
VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali
Thermal CharacterizationThermal CharacterizationTGA Seiko exstar 6000
Film Membranes
Td=404°C 30°C -> 1000°C, 10°C/min Nitrogen
0 200 400 600 800 1000
0.00
0.05
0.10
0.15
0.20
0.25
DT
G (g
i/gi
min
)
Temperature [°C]
PCL PCL CNFs 0,5% PCL CNFs 1% PCL SWNTs 1%
0 200 400 600 800 1000
0.00
0.05
0.10
0.15
0.20
0.25
DT
G (g
i/gi
min
)
Temperature [°C]
PCL film PCL CNFs 0.5 % PCL CNFs 1% PCL SWNTs 1%
VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali
Dynamo-Mechanical Dynamo-Mechanical CharacterizationCharacterization
DMADynamic Time Sweep Test f=1Hz Strain=0.3
DMA: Dynamo-Mechanical AnalysisDMA: Dynamo-Mechanical Analysis Reometric Scientific-ARES N2Reometric Scientific-ARES N2
Film
MaterialeG'medio (108Pa)
PCL film 6,3 ± 0,2
PCL CNFs 0.5% 6,7 ± 0,2
PCL CNFs 1% 8,6 ± 0,2
PCL SWNTs 1%
8,3± 0,3
VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali
CONCLUSIONSNanocomposites made with bioresorbable PCL matrix and CNSs were processed by solvent casting technique and electrospinning.
Objective: to analyze the effects of the incorporation of CNSs and their morphology on the Thermal, Mechanical and Electrical Properties
Hydrophobic surface induced by membrane process
CNSs serve the role of a plasticizer and a crystal nucleate, which enhances the polymer segmental mobility and facilitates the crystal packing simultaneously.
Elastic modulus increases significantly with introduction of CNSs in the polymer matrix.
An introduction of CNTs in the polymer matrix affects the electrical conductivity of the nanocomposite.
These studies suggest that the combination of biodegradable polymers and carbon nanostructures, opens in fact a new perspective in the self-assembly of nanomaterials and nanodevices with tunable mechanical and electrical properties.
VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali
Acknowlodgement
VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali
Thank You!! Thank You!!
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