1.  Preparation of Laminate Composite via Hand Layup
 Thin CNS-BP Deposition in the Interlaminar Region Using
Frictional Sliding
 Interlaminar Fracture Toughness Testing in Mode I and II:
 Damage Monitoring via Electrical Conductivity:
Toughening Glass Fiber Composites and
Enabling Damage Monitoring Using
Carbon Nanotube Bucky Paper
D. Kovtun1, D. Pedrazzoli2, O.G. Kravchenko2, I. Manas-Zloczower2
1 Johns Hopkins University-Baltimore, MD
2 Case Western Reserve University--Macromolecular Science & Engineering Department-Cleveland, OH
1 dkovtun1@jhu.edu
 Composite Materials:
 Layers of reinforcement are stacked in a specific pattern to
obtain required properties
 Individual layers consist of high modulus, high-strength fibers
in a matrix
 Interleaving to Arrest Crack Propagation
 GIC and GIIC serve as engineering design parameters—Energy required to propagate a crack
 GIC and GIIC denote the critical energy release rate in Mode I and Mode II
 Interlaminar fracture toughness is enhanced in the modified composite while simultaneously enabling electrical conductivity
Introduction
Results
Experimental
By measuring resistance over time with increasing crack length, it is possible to
predict the onset of crack propagation based on decreases in electrical conductivity
 Dr. Ica Manas-Zloczower, Professor of Macromolecular
Science & Engineering
 Dr. Diego Pedrazzoli-CWRU
 Dr. Oleksandr Kravchenko-CWRU
 Dr. David Schiraldi, Professor and Chairman-CWRU
 Dr. Ina Martin-MORE Center-CWRU
 Dr. Wayne Jennings-Swagelok Center-CWRU
 Financial support from the NSF Science and
Technology Center for Layered Polymeric
Systems (Grant 0423914) is gratefully
acknowledged
Acknowledgements
 Carbon nanostructure Bucky paper (CNS-BP) production
 Plasma gas functionalization for improved interfacial adhesion
with X-ray Photoelectron Spectroscopy characterization
Methods and Technology
 Composite structures in the form of laminates are extremely susceptible to crack propagation along the laminar interfaces.
 Carbon nanostructure Bucky paper (CNS-BP) is a macroscopic aggregate of cross-linked carbon nanotubes (CNTs) which has the
potential to be used as interleaf in composite materials due to its mobility, scalability, and ease of production.
 Purpose of this research is to modify glass fiber composites with a thin deposition of BP in the interlaminar region in an effort to
toughen epoxy composites widely used in aerospace, automotive, and wind energy industries
 Before deposition, the CNS-BP was treated with oxygen plasma to improve its adhesion with the polymer matrix
 The CNS-BP was deposited via shearing force to assure a very thin coating in the middle of the composite
 Laminates prepared via hand layup and compression molding were tested in Mode I and Mode II to measure interlaminar fracture
toughness
 The modified material has conductive properties that may enable potential structural monitoring of the composite
Abstract
Conclusions and Future Work
Conclusions:
 BP-CNS enables conductivity for damage monitoring
 Fracture toughness is enhanced
 Cost effective method which uses minimal CNT/CNS
Future Work:
 Implement repeatable and scalable process for
deposition of CNS BP
 Optimize monitoring of electrical resistance over time
 EMI shielding
 Thermal conductivity
Laminate composite
Interleaf film
Laminate composite
Conductive paint layer
x
P
P
Composite
laminate
Delamination crack
CNS layer deposited at
the interlaminar region
kΩ
Mode I Mode II
http://www.dtbtest.com/electromagnetic-shielding-primerxxxx
Biomedical Engineering-Frontiers and Challenges ISBN 978-953-307-309-5
Wikipedia-Author PerOx
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Average GIIC
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Resistance(kΩ)
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Resistance vs. Displacement
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Crack Propagation Before Reaching Conductive Paint Layer
Crack Propagation
Through CNS Layer