Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2022 Nov 9;7(46):42396-42407.
doi: 10.1021/acsomega.2c05496. eCollection 2022 Nov 22.

Development of Self-Healing Carbon/Epoxy Composites with Optimized PAN/PVDF Core-Shell Nanofibers as Healing Carriers

Naga Kumar C  1 , Prabhakar M N  2 , Mohamad Tarmizie Hassim  3 , Jung-Il Song  1
Affiliations

Development of Self-Healing Carbon/Epoxy Composites with Optimized PAN/PVDF Core-Shell Nanofibers as Healing Carriers

Naga Kumar C et al. ACS Omega. .

Abstract

Two-component self-healing carbon/epoxy composites were fabricated by incorporating healing agents between to carbon fiber laminates via the vacuum bagging method. Vinyl ester (VE), cobalt naphthalene (CN), and methyl ethyl ketone peroxide (MEKP) were encapsulated in a polyacrylonitrile (PAN)/Poly(vinylidene fluoride) (PVDF) shell via co-axial electrospinning. Varying nanofiber compositions were fabricated, namely, 10, 20, 30, and 40% PAN in PVDF nanofibers. The 20% PAN fibers were finalized as the shell material owing to their superior tensile properties and surface morphology. The behavior of the PAN/PVDF nanofibers encapsulating the healing agents was studied via Fourier-transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), and thermogravimetric analysis (TGA) to affirm the presence of the healing agents. Mechanical analysis in the presence of core-shell nanofibers indicated an enhancement of 7 and 5% in flexural strength and Izod impact strength, respectively. Three-point bending tests confirmed the autonomous healing characteristics of these nanofibers, which retained 62% of their initial strength after 24 h. FESEM and energy dispersive X-ray (EDX) analyses of the fracture surface confirmed that the resin was released from the nanofibers, restoring the initial properties of the composites.

PubMed Disclaimer

Conflict of interest statement

The authors declare no competing financial interest.

Figures

Figure 1
Figure 1
PAN/PVDF nanofibers: (A) FESEM images with diameter distribution histogram at low magnification and (B) EDX analysis.
Figure 2
Figure 2
(A) Overall spectra of PAN/PVDF nanofibers, (B) proposed molecular interaction between PAN and PVDF, and (C) designation of new peaks.
Figure 3
Figure 3
Thermographs of (A) PAN/PVDF, (B) V-20PNPF, and (C) M-20PNPF nanofibers.
Figure 4
Figure 4
(A) Tensile properties of PAN/PVDF nanofibers. (B) Stress–strain graph of 20PNPF and VM-20PNPF nanofibers.
Figure 5
Figure 5
(A) Flexural stress–strain graphs; (B) strength and modulus of CCP, WOHP, and WHP composites; and SEM images of (C) WOHP and (D) WHP fractured surface.
Figure 6
Figure 6
(A) Izod impact strengths of CCP, WOHP, and WHP composites. SEM images on fractured surface of (B) WOHP and (C) WHP composites.
Figure 7
Figure 7
Stress–strain curves measured during tensile testing with a strain range of 30% (elastic zone) for (A) 20PNPF and (B) VM-20PNPF nanofibers.
Figure 8
Figure 8
(A) Tensile modulus variation of 20PNPF and VM-20PNPF. Specimens before and after the third tensile stretch of (B) 20PNPF and (C) VM-20PNPF nanofibers.
Figure 9
Figure 9
Flexural stress–strain curves of (A) CCP and (B) WHP composites at 24 h interval.
Figure 10
Figure 10
FESEM images and their EDX analysis at ruptured portions of (A) V-20PNPF and (B) M-20PNPF nanofibers.
Figure 11
Figure 11
(A, C) FESEM images of fractured surface of WHP composites. (B, D) Higher magnification of (A) and (C).
Figure 12
Figure 12
(A) FESEM Image of fractured surface. (B) EDX analysis of PAN/PVDF nanofibers. (C) EDX analysis of epoxy matrix. (D) EDX analysis of healing agents.
See this image and copyright information in PMC

References

    1. Du Y.; Song C.; Xiong J.; Wu L. Fabrication and mechanical behaviors of carbon fiber reinforced composite foldcore based on curved-crease origami. Compos. Sci. Technol. 2019, 174, 94–105. 10.1016/j.compscitech.2019.02.019. - DOI
    1. Wang F. S.; Zhang Y.; Ma X. T.; Wei Z.; Gao J. F. Lightning ablation suppression of aircraft carbon/epoxy composite laminates by metal mesh. J. Mater. Sci. Technol. 2019, 35, 2693–2704. 10.1016/j.jmst.2019.07.010. - DOI
    1. Bae J.-H.; Lee S.-W.; Chang S.-H. Characterization of low-velocity impact-induced damages in carbon/epoxy composite laminates using a poly (vinylidene fluoride–trifluoroethylene) film sensor. Composites, Part B 2018, 135, 189–200. 10.1016/j.compositesb.2017.10.008. - DOI
    1. Gholizadeh A.; Najafabadi M. A.; Saghafi H.; Mohammadi R. Considering damages to open-holed composite laminates modified by nanofibers under the three-point bending test. Polym. Test. 2018, 70, 363–377. 10.1016/j.polymertesting.2018.07.021. - DOI
    1. Tsilimigkra X.; Baltopoulos A.; Tsantzalis S.; Kotrotsos A.; Siakavellas N.; Kostopoulos V.; Florez S. Strategies on implementing a potential self-healing functionality in a composite structure. Cienc. Tecnol. Mater. 2016, 28, 147–154. 10.1016/j.ctmat.2016.05.001. - DOI