1. Nanosize Surface Electromodification of Carbon Fibers by Conductive Polymers  and Their Characterizations
Prof.Dr.A.Sezai.SARAÇ
Istanbul Technical University
Department of Chemistry &
Polymer Science and Technology
Maslak 80626
Istanbul,Turkey

2. of polymeric composites
Carbon fiber reinforcement
of polymeric composites
Carbon fibers(CF) are used in composites(i.e.,PAN based CF) in order to produce materials of lower density and greater strength. advanced structural materials: aircraft, spacecraft, and suspension bridges –
The most widely used composite material in tactical aircraft is a carbon fibre/epoxy
A polymeric ‘interface’ acting as a coupling agent, improve the interfacial properties between reinforcing (carbon) fibers and the polymeric matrix .
5-7μ
A.S. Sarac, A. Bismarck, E. Kumru, J. Springer,Synth. Met. 123 (2001)
E.Kumru,J.Springer,A.S.Sarac,A.Bismarck.,  Synth. Met.  123(2001)

3. Biosensor Appl.
Electromodified carbon fibers also have potential for biosensor applications as microelectrodes
-working in small volumes of solutions-
Homogeneous Conductive Polymer coated -surface functionalities is suitable for the miniaturization of electrode system for a particular analyte.
Several copolymer and polymer coated electrodes(Cz based) were shown to be an effective disposable microelectrode system for the determination of p-aminophenol at low detection limits
M. Jamal, E. Magner, A.S.Sarac, Sensors and Actuators 97 (2004)59-66

4. Carbon Fiber Reinforcement applying force to a composite material, the brittle matrix cracks at low stress levels > fibres take over
Woven fiber
Epoxy resin –polymer matrix

5. The structure & comp. of copolymeric films, plays an important role on the final properties of modified carbon surface The coating parameters & characterization of these functionalised thin films are important . Improving the interfacial adhesion Advanced Composites- Interfacial adhesion control the level of fiber/matrix adhesion
A.S.Sarac,M.Serantoni,,A.M.T.Syed,V.J.Cunnane ,Appl.Surface Sci.,(2004) 229,13-18
A.S.Sarac,A.M.T.Syed,M.Serantoni,,V.J.Cunnane J.Mater.Sci.Lett.(2004) 39,

6. Surface Analysis (the characterizations of electrografted thin polymeric film ~10-50nm film characterizations-Fast and simple for org. thin film coating & charac. -Nanosize Change of functionality of surface)
Spectroscopic
Functionalities
FTIR-ATR
Raman
Composition
- XPS,EDX,FIBSIMS
Electrochemical Impedance Spectroscopic studies
Morphological
SEM
AFM

7. AFM of Electrogrowth of P[Cz-co-AAm] onto HOPG Graphite Higher scan rates (100 mV/s) : thin (hf  22 nm) coatings . Lower scan rates (≤ 50 mV/s) ~50 nm
A.Bismarck,A.Menner,J.Barner,A.F.Lee,K.Wilson,
J.Springer,J.P.Rabe,A.S.Sarac, Surface Coat .Tech. 145(2001)

8. Current density vs cycle number (▪): 1. 53V (●): 1
Current density vs cycle number (▪): 1.53V (●): 1.04 V and the coating thickness (▫) from the ellipsometric angles

9. Galvanostatic vs. Cyclic voltammetry
polymerization rate vs.film growth.
CV :
Galvanostatic process thin coating (hf  15 nm) & smoother (RMS = 13 nm),

10. polyethylenedioxythiophene (PEDOT)
AFM of Untreated Carbon fiber(r~5.6 μ)
polyethylenedioxythiophene (PEDOT)

11. Polyterthiophene/CF

12. Electrocoating of polytetrathiophene onto carbon fiber by cyclic voltammetry 10mM TEABF4/MeCN. 10 cycles at 100mVs-1
2 mM Polytetrathiophene in 10 mM TEABF4 / PC ,
20 mV/s ,RMS 50 nm (1mm2) 5 scan
SARAC,A.S.,EVANS,U.,SERANTONI,M.,CUNNANE,V.J.,Carbon 41,14 (2003)

13. polytetrathiophene formation on the surface

14. polymethylcarbazole

15. Poly[MCz] on CFME in 0.1 M NaClO4 in PC at 100 mV/s.

16. Poly[MPy] on CFME in 0.1 M NaClO4 in PC at 100 mV/s.

17. Poly[MPy-co-MCz] on CFME in 0
Poly[MPy-co-MCz] on CFME in 0.1 M NaClO4 in PC at 100 mV/s, [MPy]& [MCz]=0.001 M

18. Poly[MPy-co-MCz] in monomer-free solution
Poly[MPy-co-MCz] in monomer-free solution. a) 10 mV/s, b) 20 mV/s, c) 50 mV/s, d) 100 mV/s, e) 200 mV/s in a 0.1 M NaClO4 / PC solution. All samples were subsequently cycled 8 times

19. Scan rate dependence of the copolymer film : Plots of anodic and cathodic peak currents vs. the square root of scan rate Inset: : change in anodic and cathodic peak currents with scan rate in monomer free solution of 0.1M NaClO4/PC
Randles Selvic
ip = (2.69 x 108) n3/2 A C D1/2 ν1/2

20. Effect of feed ratio of monomers on current ,solid state conductivity and yield.

21. Comparison the peak current densities of electro-growth of the copolymer films obtained by CV and solid state conductivity in different monomer ratios

22. Anodic peak current densities of Poly[MPy-co-MCz] in different electrolytes using multiple (50 cycles) in monomer-free solution at 100 mV/s, [MPy] &[MCz]=0.001 M.

23. Poly(N-vinylcarbazole-co-Vinylbenzenesulfonic acid)
Ungrafted CF,
P[NVCz-co-VBSA] grafted CF
100 mA 4 hrs
200mA 2 hrs
Element
NVCzVBSA2
NVCzVBSA3 C
76.57
85.83 N
2.84
3.76 O
15.20
9.03 S
2.83
0.15
Element
NVCzVBSA2
NVCzVBSA3 C
76.57
85.83 N
2.843
3.76 O
15.2
9.033 S
2.825
0.147

24. Poly[NVCz-coVBSA] NVCzVBSA3

25. Reflectance FTIR of thin carbazole copolymer film on CF

26. Poly[Methylthiophene-co-carbazole]

27. Reflectance FTIR & EDX of electrografted P[MeTh-co- Cz] thin copolymer film
A.S.Sarac, J.Springer., Surface Coat.Tech.(2002) 160,

28. Raman Spectra 1330 cm-1 C=C , 1567cm-1 C-C ring

29. XPS P[Cz-co-MeTh] Carbon fiber
C=S
C-N
C=O
P[Cz-co-MeTh] Carbon fiber
at different initial comonomer feed ratios
A.S.Sarac, M.Serantoni, T.Syed, J.Henry, V.J.Cunnane, J.B.McMonagle, Appl.Surface Sci.. 243(1-4)( 2005)
A.S.Sarac, A.MT.Syed, M.Serantoni, J.Henry, V.J.Cunnane, J.B.McMonagle.
Appl.Surface Sci. Sci.222,1-4(2004)

30. Reflectance FTIR of vinyl group in copolymer

31. Poly[MeTh-co-NVCz]

32. Electrocoated carbon fibre single fibre pull-out test
Electrocoated carbon fibre single fibre pull-out test. a)The fibre was partially pulled-out of the electrodeposited coating. b) fibre completely pulled-out of the electrodeposited coating.
The adhesive strength CF/PMMA matrix resulted in 100% improved in thin and homogeneous PMMA coatings.
(the interfacial shear strength not so good in thicker coatings)
So, electrocoating of MMA can improve the interfacial performance of
a carbon fibre reinforced PMMA model composite.

33. % concentration (determined from XPS ) versus cps (determined from FIBSIMS measurements ) P[NVCz-co-MeTh]
M.Serantoni, A.S.Sarac,D.Sutton,V.J.Cunnane, Surface Coat.Tech..( 2005) (in press)

34. Nanosize Surface chemistry & Morphology of CP electrografting onto Carbon Foam & CF surface &Electrochemical Impedance Their Applications
Thin conductive polymer films can be covalently electrografted onto the CF
Surface structure and composition can be analysed in nanoscale (> 20 nm)(XPS,Raman ,FTIRATR)
Surface morphology (SEM,AFM)
improve the interfacial shear strength
reinforcement appl.
biosensor applications

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Istanbul Bosphorous Asia-Europe