1. VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali ELECTROSPUN NANOHYBRID MEMBRANES BASED ON BIORESORBABLE POLYMER AND CARBON NANOSTRUCTURES Ilaria 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

2. VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali Aim The purpose of this study was to investigate nanohybrid systems based on bioresorbable Polymers and CNSs, in different Morphological structures.  Composition  Morphology

3. VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali Outline  State of the art  Materials & Methods  Nanocomposite Development: Membranes & Film  Nanocomposite Charaterization: Morphological & Thermal & Dynamo-Mechanical  Conclusions

4. VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali Bioresorbable Polymers NANOCOMPOSITE n PGA n PLA 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

5. VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali 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.”

6. VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali CNTs Why CNTs?Extraordinary properties Structure  Nano and um dimensions  High aspect ratio: 1000  High specific surface area: 1400m 2 /g  High ratio interfacial area/vol: 1000 um -1  Large number density/vol: 10 6 CNTs/um 3  Size scale comparable to interface layer (1-10 nm)  Chirality based on rolling direction  Found as single wall and Multi wall tubes Unique Structure

7. 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.

8. VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali ElectroSpinning 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 DC The 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.

9. VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali Materials ε-PCL Sigma Aldrich Polymer Matrix Methods Solvent Casting in CHCl 3 CNFs: Carbon NanoFibers, Pyrograf Single Wall Carbon Nanotubes, Thomas Swan SWNTs: Single Wall Carbon Nanotubes, Thomas Swan & Co.Ltd. Electrospinning CNSs Flat Film d=200 µm Porous Membranes 1 % wt 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

10. VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali SWNTs FESEM - Zeiss Supra25Seiko exstar 6000 T=555°C Residual Mass=3% Metal catalist PURITY TGA In 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

11. VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali CNFs Carbon Nanofibers TGA In Air 5°C/min (30-1000)°C FESEM - Zeiss Supra25 Seiko exstar 6000

12. VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali Morphological Analysis Field Emission Scanning Electron Microscopy FESEM-Supra 25 Zeiss PCL Membranes

13. VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali CONTACT ANGLE FTA 1000 AnalyserSurface Characterization (118± 1)° PCL MembranesPCL Film hydrophobic surface Water (74.5± 0.5)° MaterialsWater Contact Angle PCL(74.5± 0.5)° PCL+1%SWNTs(74.2± 0.5)°

14. VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali Morphological Analysis Field Emission Scanning Electron Microscopy FESEM-Supra 25 Zeiss Film, fracture surfacePCL+ CNFs 1% wt

15. VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali Morphological Analysis Field Emission Scanning Electron Microscopy FESEM-Supra 25 Zeiss Film, fracture surfacePCL+ SWNTs 1% wt

16. VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali Morphological Analysis Field Emission Scanning Electron Microscopy FESEM-Supra 25 Zeiss Nanohybrid Membranes PCL+ CNFs 1% wtSurface

17. VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali Morphological Analysis Field Emission Scanning Electron Microscopy FESEM-Supra 25 Zeiss Nanohybrid MembranesPCL+ CNFs 1% wtCross Section

18. VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali Morphological Analysis Field Emission Scanning Electron Microscopy FESEM-Supra 25 Zeiss Nanohybrid MembranesPCL+ SWNTs 1% wtSurface

19. VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali Morphological Analysis Field Emission Scanning Electron Microscopy Nanohybrid MembranesPCL+ SWNTs 1% wtCross Section

20. VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali Dielectric Characterization HP4284 20 Hz-1MHz 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 PCL Nanocomposite

21. VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali Thermal Characterization 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 Film PCL + CNSs

22. VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali Thermal Characterization 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 PCL + CNSs

23. VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali Thermal Characterization Xc(%)=ΔH/ΔH 0 ΔH 0 = 136 J/g Polymer 41 (2000) 9073–9080 Materials ΔH m1 (J/g ) ΔH c (J/g ) ΔH m2 (J/g ) T m1 (°C)T c (°C)T m2 (°C)X c1 (%)X c2 (%) PCL pellets 57,1± 0,946,0± 0,540,6± 0,658,7± 0,317,8 ± 0,756,0± 0,942,0± 0,529,9± 0,4 PCL film 67 ± 249 ± 139,8 ± 0,861,61 ± 0,0122.7 ± 0,256,34 ± 0,0850 ± 130.2 ± 0,6 PCL SWNTs 1% wt 60 ± 146 ± 142,6 ± 0,858,6 ± 0,232,1 ± 0,155,5 ± 0,244,5 ± 0,731,3 ± 0,6 PCL CNFs 1% wt 56,8 ± 0,146,1 ± 0,339,6 ± 0,358,9 ± 0,229,88 ± 0,0955,6 ± 0,341,8 ± 0,129,1 ± 0,2 SC_PCL 68,5 ± 0,955 ± 145 ± 157,7 ± 0,124,59 ± 0.0155,6 ± 0,250 ± 133,1± 0,7 SC_PCL CNFs 1% wt 57,7 ± 0,349,7± 0,343,1 ± 0,857,5 ± 0,332,6 ± 0,255,9 ± 0,442,4 ± 0,231,7 ± 0,6 SC_PCL SWNTs 1% 56,1 ± 0,251,0 ± 0,644 ± 257,7 ± 0,333,97 ± 0,0956,1 ± 0,341,3 ± 0,232 ± 1

24. VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali Thermal Characterization TGA Seiko exstar 6000 FilmMembranes T d =404°C 30°C -> 1000°C, 10°C/min Nitrogen

25. VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali Dynamo-Mechanical Characterization DMA Dynamic Time Sweep Test f=1Hz Strain=0.3 DMA: Dynamo-Mechanical AnalysisReometric Scientific-ARES N2 DMA: Dynamo-Mechanical Analysis Reometric Scientific-ARES N2 Film MaterialeG' medio (10 8 Pa) 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

26. VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali CONCLUSIONS  Nanocomposites 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.

27. VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali Acknowlodgement

28. VI Convegno Nazionale sulla Scienza e Tecnologia dei Materiali Thank You!!