Hybrid High-Strength Carbon-Fiber/Epoxy Composites Reinforced
with Self-Healing Nanofibers at Interfaces
(ND NASA EPSCoR Seed Grant $28,610, 4/16/2011-4/15/2012)
Xiangfa Wu, PhD.
NDSU Mechanical Engineering
• NASA space mission highly relies on spacecrafts made of lightweight composites
(i.e., carbon fiber reinforced polymer composites) with high specific strength
and stiffness and superior damage tolerance
• Goal of proposed research
- Development of a novel interfacial self-healing strategy for aerospace
polymer composites with low-cost, low-weight penalty, and easy incorporation into
existing manufacturing process of high-strength polymer composites
- Formulation of reliable route for healing-agent encapsulation at nanoscale(two orders
below existing ones) and processing of concept-of-proof hybrid multiscale
polymer composites with self-healing interfaces
- Exploration of potential interfacial self-healing
mechanism for controlled manufacturing
Interfacial failure
Relevance to NASA
•
Research is directly related to NASA interests in developing high-strength lightweight
polymer composites with high damage tolerance and damage self-repairing function
in low cost.
•
Proposed novel hybrid multiscale composites are expected to remarkably enhance the
damage tolerance and fatigue lifetime, substantially reduce the structural maintenance
cost, and increase the integrity and reliability of the resulting composite structures.
As an example, if an antenna of the space station was made of such high-strength
advanced composites with damage self-repairing function, it could be possible to save
huge maintenance fees relating shuttle launches and space walk.
Accomplishments
•
•
•
•
Successful fabrication of continuous coreshell nanofibers loaded with liquid healing
agent by coelectrospinning
Successful fabrication of proof-of-concept
carbon-fiber/epoxy composites reinforced
with self-healing core-shell nanofibers at
interfaces
(Dzenis, 2008)
Reliable mechanical characterization of selfhealing effect in stiffness recovery (up to
100% recovery) after damage
Exploration of interfacial toughening & selfhealing mechanisms via SEM fractography
(Wu et al., 2012)
Collaborations, Student Involvement & Publications
•
Collaborations
- Dr. Bin Chen, NASA Ames Research Center, CA
- Dr. Alexander L. Yarin, Univ. of Illinois-Chicago, IL
- Dr. Hao Fong, South Dakota Sch. of Mines & Tech., SD
•
Research Assistants Involved
- Zhengping Zhou (Ph.D. student, ongoing); - Arifur Rahman (M.S., 2/12); - Robert Jensen (M.S.,
8/11); - Youhao Zhao (undergraduate, summer 2011)
•
Publications
1. X.F. Wu, A. Rahman, & Z.P. Zhou, “Hybrid high-strength carbon-fiber/epxoy composites reinforced
with ultrathin toughening and self-healing core-shell fibers at interfaces,” NDSU Technology Transfer
Office, February 2, 2012 (Invention Disclosure).
2. Z.P. Zhou, X.F. Wu, X.Q. Gao, L. Jiang, Y. Zhao, & H. Fong, “Parameter-dependency of conic angle of
nanofibers during electrospinning,” J. Phys. D: Appl. Physi. 44, 435401 (2011) (6 pages).
3. S. Sinha-Ray, D. Pelot, Z.P. Zhou, A. Rahman, X.F. Wu, & A.L. Yarin, “Encapsulation of self-healing
materials by coelectrospinning, emulsion electrospinning, solution blowing and intercalation,” J. Mater.
Chem. 22, 9138-9146 (2012).
4. Q. Chen, L.F. Zhang, M.K.Yoon, X.F. Wu, R.H. Arefin, & H. Fong, “Epoxy composites reinforced
and/or toughened with electrospun SiO2 nanofibers,” J. Appl. Polym. Sci. 124, 444-451 (2012).
5. X.F. Wu, A. Rahman, Z..P. Zhou, D. Pelot, S. Sinha-Ray, B. Chen, & A. L. Yarin, “Polymer composites
with engineered self-healing interfaces by electrospun core-shell nanofibers,” (under review)
Future Plans for Proposals
•
AFOSR: Novel high-strength multiscale polymer composites with engineered selfhealing interfaces ($613,317) (submitted, PI; co-PI: A.L. Yarin, UIC)
•
NSF CMMI: Continuous nano-scaled carbon fibers with superior mechanical
properties and their innovative composites with exceptionally high performances
(co-PI) ($334,198) (submitted, co-PI; PI: H. Fong, SDSMT)
•
DARPA (under preparation)