Dispersed CNT in BA based latex (sphere 200 nm) Carbon nanotube - PowerPoint PPT Presentation

2 Dispersed CNT in BA based latex (sphere 200 nm) Carbon nanotube decorated poly(methyl methacrylate) microbeads Double percolation of CNT and n-Pani J. Lu, J.F. Feller, B. Kumar, M. Castro, Y.S. Kim, Y.T. Park and J.C. Grunlan, « Chemo-sensitivity of latex-based films containing segregated networks of carbon nanotubes « , Sensors and Actuators B: Chemical B 155 (2011) 28–36. J. Lu, B. J. Park, B. Kumar, M. Castro, H. J. Choi and J-F. Feller, « Polyaniline nanoparticle–carbon nanotube hybrid network vapour sensors with switchable chemo-electrical polarity « , Nanotechnology, 21, 255501 (2010) J-F Feller, J. Lu, K. Zhang, B. Kumar, M. Castro, N. Gatt, H.J. Choi , « Novel architecture of carbon nanotube decorated poly(methyl methacrylate) microbead vapour sensors assembled by spray layer by layer « , Journal of Materials Chemistry, 2011, 21, 4142.

3 10 7 -10 9 Percolation Percolation ( ) − t ρ CPC = ρ f Φ − Φ c t threshold threshold Transition Insulator / Conductor 10 -1 - 10 2 Φ c Filler content φ (%) � First step: establishing percolation curve of CPC, which depends on intrinsic components properties (aspect ratio, interaction, conductivity conductivity…) and processing conditions (shear rate, temperature, viscosity…) ) and processing conditions (shear rate temperature viscosity ) � Second step: selecting level of conductivity to reach best compromise between sensitivity / stability for different external sollicitation (chemical, mechanical, heat) (just above percolation threshold) ( , , ) (j p ) J-F. Feller, M. Castro and B. Kumar, « Polymer carbon nanotube conductive nanocomposites for sensing« , in Polymer carbon nanotube composites: Preparation, properties and applications, Edited by T McNally, Queen’s University Belfast, UK and P Pötschke, Leibniz-Institut für Polymerforschung Dresden e.V. (Leibniz Institute of Polymer Research Dresden), Germany, ISBN 1 84569 761 8, ISBN-13: 978 1 84569 761 7, Q1 2011, 750 pages

4 � Layer by Layer Spray technique offers the opportunity to finely control the 3D architecture of the conductive structure via adjustable parameters (concentration, number of layers, CPC/solvent interaction) � Furthermore this technique offers great versatility to match with several kind of external sollicitationation KUMAR B., LU J., CASTRO M., FELLER J. F.* , « Conductive bio-Polymer nano-Composites (CPC): Chitosan-carbon nanotube transducers assembled via spray layer by layer for volatile organic compound sensing « ,Talanta, Volume 81, Issue 3, 908-915 (2010).

5 PS-CNP 500 µm 500 µm 1 µm 10 µm 30 µm PC-CNT 30 µm 200 nm � PS-CNP films assembled onto interpenetrated electrodes by sLbL lead to high specific surface transducers which can be tailored with PS and CNP structure hi h b t il d ith PS d CNP t t � PC-CNT microdroplets weld during assembly. PC helps structuring CNT network together and brings chemical specificity FELLER J. F.* , GROHENS Y., « Electrical response of Poly(styrene)/carbon black conductive polymer composites (CPC) to methanol, toluene, chloroform and styrene vapors as a function of filler nature and matrix tacticity « , Synthetic Metals, 154, 1-3, 193-196 (2005). LU J., KUMAR B., CASTRO M., FELLER J. F.* , « Vapour sensing with conductive polymer nanocomposites (CPC): Polycarbonate-carbon nanotubes transducers with hierarchical structure processed by spray layer by layer « ,Sensors & Actuators B: Chemical, 140, 451-460 (2009)

6 N. S. Lewis, Accounts of Chemical Research, 37, 9, 663-672 (2004 ) Toluene G. Peng, E. Trock, H. Haick, Nano Lett. 2008, 8 (11), pp 3631–3635 Chloroform Ethanol Water Methanol THF Volatile Organic Compounds CPC sensor Pattern Signal processing Data Analysis matrix recognition � Responses from non-specific sensor are analyzed in parallel � Summarized results are then further compiled using Principal Component Analysis to get fingerprint of tested vapours � Sensitivity, selectivity and reproducibility are still important challenges M. Castro, B. Kumar, J. F. Feller, Z. Haddi, A. Amari, B. Bouchikhi, « Novel e-nose for the discrimination of volatile organic biomarkers with an array of carbon nanotube (CNT) conductive polymer nanocomposite (CPC) sensors « , Sensors and Actuators B: Chemical, 2011, Vol. 159, Issue 1, 213-219.

7 ρ resistivity, a and b constant and Z distance between two particles m) tivité ( Ω .cm Résist PVC Effect [Vapour] � CPC are composites materials which are sensitive to inter-particles distance � Electrons can go through the conductive network by tunelling effect � Electrons can go through the conductive network by tunelling effect FELLER J. F.* , GROHENS Y., « Evolution of electrical properties of some conductive polymer composite textiles with organic solvent vapours diffusion .« , Sensors & Actuators B: Chemical, 97, 2-3, 231- 242 (2004).

8 Model LHC de se amplitud Henry diffusion Langmuir adsorption A r respon f’ Clustering f’’ − ( ) b .(f' ' f).f = + + − n ' L A k . f f f ' . f + r H (1 b .f) L φ vapour % φ vapour % � b L Langmuir affinity constant, f solvent fraction, f’ solvent fraction when clustering occurs, f solvent fraction when Langmuir is replaced by Henry diffusion, k H Henry solubility coefficient (slope of 2 nd region in the curve). In g p y y y y ( p g ) H the third region, A R (or Δ m/m) increases exponentially, n’ is the average number of water molecule within cluster. This acceleration comes from solvation of the polymer matrix which enhance the solubility of the penetrant molecules. LU J., KUMAR B., CASTRO M., FELLER J. F.* , « Vapour sensing with conductive polymer nanocomposites (CPC): Polycarbonate-carbon nanotubes transducers with hierarchical structure processed by spray layer by layer « ,Sensors & Actuators B: Chemical, 140, 451-460 (2009)

9 10 Toluene vapour PCLc+PCL-g-1% CNT PCLc-1% CNT PCL-g-1% CNT 8 8 PCLs-1% CNT 6 A R A 4 2 0 0 900 1800 2700 3600 4500 Time/ s � Ring Opening Polymerization of ε -caprolacton on CNT, induces both better dispersion and higher compatibility with PCL matrix. � PCL-grafted-CNT also induces an increase in chemo-electrical response CASTRO M., LU J., BRUZAUD S., KUMAR B., FELLER J. F.* , « Carbon nanotube/poly(e-caprolactone) composite vapour sensors « , Carbon, 47, 1930-1942 (2009).

10 With a and b constants � Relative resistance amplitude is in good agreement with reciprocal interaction parameter χ 12 (Flory Huggins) � This could help optimizing the selection of CPC sensor by predicting their selectivity if assembled in electronic nose KUMAR B., LU J., CASTRO M., FELLER J. F.* , « Conductive bio-Polymer nano-Composites (CPC): Chitosan-carbon nanotube transducers assembled via spray layer by layer for volatile organic compound sensing « ,Talanta, Volume 81, Issue 3, 908-915 (2010).

11 Depending on the formulation, the CPC micro-fibers allow the detection of a specific temperature (boy temperature 35 ° C, or � p g p p ( y p pain yield temperature 55 ° C) � Very encourageing results have been obtained during the Inteltex European Project. J-F. Feller, M. Castro and B. Kumar, « Polymer carbon nanotube conductive nanocomposites for sensing« , in Polymer carbon nanotube composites: Preparation, properties and applications, Edited by T McNally, Queen’s University Belfast, UK and P Pötschke, Leibniz-Institut für Polymerforschung Dresden e.V. (Leibniz Institute of Polymer Research Dresden), Germany, ISBN 1 84569 761 8, ISBN-13: 978 1 84569 761 7, Q1 2011, 750 pages

12 Part fixed in clamps (20 l (20 Length (100 mm) mm) Efficient CPC Efficient CPC Wire connection Wire connection gauge (20 mm) (2.5 mm) Width (10 mm) 14 2,5 Résistance relative (%) deformation (%) 12 %) 2 rmation (% ésistance ) ative (%) 10 1,5 8 6 1 defor Ré rel 4 0,5 2 0 0 0 0 0 200 400 600 800 Temps (s)

13 Modélisation des transferts de chaleur et de la diffusion des M déli ti d t f t d h l t d l diff i d � petites molécules dans les systèmes hétérogènes CPC -> couplage électrique Optimisation des architecture CPC pour le suivi de santé et de O ti i ti d hit t CPC l i i d té t d � déformation dans les structures composites Nouvelle architectures micro/nano pour les nez électroniques � dédiés au diagnostique précoce des maladies par l’analyse de l’haleine (cancer du poumon …) Utilisation des senseurs CPC pour la caractérisation des � performances barrières de films obtenus pas LbL électrostatique p p q