Sosa, Edward

NASA Technical Reports Server

Multifunctional Nanocomposite
with Healing and Health 
Monitoring Capabilities
Edward Sosa
ERC Inc.
MRS Fall Meeting 
December 02, 2013
https://ntrs.nasa.gov/search.jsp?R=20140003583 2019-08-29T14:23:11+00:00Z
Applications in Space Exploration
• Composites for Structural Materials
light weight → mass saving → cost effective
• Applications
crew cabin primary & secondary structures
heavy lift launch systems
rovers 
• Concerns
damage tolerance → mass saving loss
• In-Space Repair
enable safe, reliable long duration 
space exploration
- additive manufacturing
- self repairable systems
December 2, 2013
Re‐
Polymerization 
Hollow Fiber
Microencapsulation
Self Healing Approaches
• Variety of Repair Mechanism
 Irreversible Systems
 Covalently Bonded Polymers
 Non-Covalently Bonded Polymers
 Ionomers
 Hydrogen Bonded Polymers
 Metal Ligand Coordination Polymers
 Nanoparticle Diffusion
• Irreversible Systems
 Encapsulation Techniques
 Autonomous, quick, damage inspection
 Single event, loading, complex machining
• Reversible Systems
 Repolymerization Techniques
 Multiple healing, independent of loading,
allows complex shapes
 Not autonomous, healing timeframe
December 2, 2013
B.J. Blaiszik,  Polymer, 
2009
G.J. Williams, Composites: Part A, 2009
J.S. Park, Composites 
Sci. Technol. 2009
Multi-functional Nanocomposites
• Reversible Polymerization Induced Healing
photo-induced reversible crosslinking or thermal  
activation
increase lifetime performance
• Thermally Activated Re-Polymerization
reversible bond formation
retro- Diels Alder chemistry
• Introduction of Multi-Functional Properties
enhanced electrical conductivity
improved thermal management
radiation shielding/hardness
reduced gas permeation 
• Structural Health Monitoring
damage detection
damage repair evaluation
December 2, 2013
• Carbon Fiber Coating
 spraying dispersed CNTs
 densification of spun MWCNTs
• Nanotube Chemical Modification
 functionalization of SWCNTs & MWCNTs
 furan & maleimide chemistries
• Composite Fabrication
 [0,60,-60]2s fiber orientation
 resin transfer molding/wet lay up
• Other Nano-additives
 graphene, boron nitride nanotubes (BNNT)
Composite Fabrication
+
December 2, 2013
Composite Panels
Panel Number Nano-Additive Inclusion
1 Control – carbon fiber only
2 Upper ply coated with spun MWCNT, lower 5 plies sprayed with MWCNTs
3 Spray coated fibers with Mitsui MWCNTs lot 061220-24
4 Spray coated fibers with Mitsui MWCNTs lot 061220-24
5 Spray coated fibers with Mitsui MWCNTs lot 05072001K28
6 Spray coated fibers purified laser SWCNTs
7 Unidirectional (0˚ orientation) spun MWCNTs on front side only
8 Unidirectional (0˚ orientation) spun MWCNTs on front side only
9 Bi-directional spun MWCNTs with dispersed purified HiPco SWCNTs
10 Bi-directional spun MWCNTs with dispersed purified PLV SWCNTs
December 2, 2013
Nanotube Residency
December 2, 2013
10μm10μm
2μm
1μm
• MWCNTs show mixed behavior
• Some migrate into matrix, others   
remain in close proximity to 
fibers
• SWCNTs remain in close proximity 
to fibers
Nanotube Residency
December 2, 2013
10 μm 10 μm
200 nm
2 μm
• s-MWCNTs stay highly intact 
and in close proximity to fiber
• SWCNTs directly dispersed in 
resin form small aggregates with 
matrix
• s-MWCNTs located near fibers
Electrical Properties
Panel Surface Resistance (kΩ)
1 ∞
2 ∞
3 3.45
4 ∞
5 3.00
6 ∞
7 0.175
8 9.55
9 1.62
10 104.8
December 2, 2013
• Measured with 4-point probe in 2-point 
configuration
• Measured in 9 locations of each side of 
panel
• Lowest measurement reported
• Similar measurements were observed for 
through thickness measurements
• Greater loadings and better dispersion are 
expected to improve electrical conductivity
• Type specific CNTs would be most 
desirable
Thermal Properties
0 20 40 60 80 100
Temperature (◦C)
Glass Transition
panel 10
panel 9
panel 8
panel 7
panel 6
panel 5
panel 4
panel 3
panel 2
panel 1
1
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
30 50 70 90 110
C
p
 
(
J
/
g
•
C
)
Temperature (C)
Heat Capacity
panel 1
panel 2
panel 3
panel 4
panel 5
panel 6
panel 7
panel 8
panel 9
panel 10
December 2, 2013
December 2, 2013
Thermal Conductivity
0.4
0.45
0.5
0.55
0.6
0.65
0.7
0.75
0.8
30 40 50 60 70 80 90 100 110
T
h
e
r
m
a
l
 
C
o
n
d
u
c
t
i
v
i
t
y
 
(
W
/
(
m
∙
K
)
Temperature (C)
Thermal Conductivity ‐ Linear Fit
Linear (panel 1)
Linear (panel 2)
Linear (panel 3)
Linear (panel 4)
Linear (panel 5)
Linear (panel 6)
Linear (panel 7)
Linear (panel 8)
Linear (panel 9)
Linear (panel 10)
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
10000
30 50 70 90 110
D
i
m
e
n
s
i
o
n
a
l
 
C
h
a
n
g
e
 
(
u
m
\
m
)
Temperature (C)
Thermal Expansion
panel 1
panel 7
panel 9
Mechanical Analysis
• Composite panels impacted with forces of x and y ft·lb
• Impacted surfaces inspected optical and electron microscopy
• Composites cut into smaller 10 x 50 mm specimens for DMA
• Addition of CNTs improves the mechanical properties of composite
0
10000
20000
30000
40000
50000
60000
70000
80000
0 20 40 60 80 100 120
S
t
o
r
a
g
e
 
M
o
d
u
l
u
s
 
(
M
P
a
)
Temperature (C)
panel 1
panel 4
panel 5
panel 6
panel 9
December 2, 2013
December 2, 2013
Microwave Heating
• Nanotubes well known to absorb microwave energy with high efficiency
• Intent is to use microwave absorption as means to supply thermal energy 
for repolymerization
• Additional improvement to thermal conductivity should also improve 
heating efficiency (power-time to reach desired temperature
• Composite panels exposed to 100W microwaves with in situ thermal 
imaging 
Control MWCNTs SWCNTs S-MWCNTs
Structural Health Monitoring
• Impacted panels show localized heating in area of impaction
• Localized hot spot due to exposed CNTs that bridge cracks
• Damage visible with greater resolution than flash thermography – possible 
tool for damage inspection
• Goal is to used localized heating for real time health monitoring
December 2, 2013
Conclusions
• Nanocomposites fabrciated using a variety of carbon nanotube materials
• Addition of CNTs introduces multi‐functionality into composite increasing 
electrical and thermal conductivity while enhancing strength
• CNTs may have interactions with polymer matrix facilitating bond dissociation
• Microwave exposure of composite shows improved heating efficiency
• Microwave heating with in‐situ thermal profiling can be used for damage 
inspection and possible health monitoring
• Better control of dispersion is expected to further improve properties
December 2, 2013
Acknowledgements
Dr. Mary Jane E. O’Rourke
Dr. Thomas Darlington
Brian Hanos
Dr. Anvar Zhakidov
Dr. John Ferrais
William Holmes
Dr. Mark Sanders
December 2, 2013


Multifunctional Nanocomposite with Healing and Health Monitoring Capabilities

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