The document outlines experiments conducted on the self-healing properties of acrylic materials. It discusses testing performed on VHB 4910 tape to analyze how its self-healing efficiency increases with healing time and temperature through hydrogen bonding and molecular chain diffusion. Experiments were also conducted developing a self-healing coating for magnesium alloys based on layer-by-layer deposition of polyelectrolytes and graphene oxide, finding the coating healed scratches within 10 minutes when exposed to water. Characterization showed the coating improved corrosion resistance the most when incorporating graphene oxide.

1. Fan Fan
Supervisor: Jerzy Szpunar
.The Self-Healing Mechanism
and Application of Acrylic
Materials_.

2. Outlines
Introduction
Objectives
Experiments on VHB 4910
Experiments on the coating
Conclusion

3. Outlines
Introduction
Objectives
Experiments on VHB 4910
Experiments on the coating
Conclusion

4. What is self-healing?
The most common self-healing
material is our skin which can
recover from injuries
intrinsically.
Image source: healthnbodytips.com/wp-content/uploads/2015/03/Benefits-of-
Drinking-Hot-Water-for-Skin1.jpg?b0bc0c

5. What can self-healing do?
The most successful industrial
application of self-healing
materials is the self-healing back
cover of a LG cellphone.
Image source: www.pcadvisor.co.uk/review/high-end-smartphones/lg-g-flex-
curved-smartphone-review-3496524/

6. Self-Healing Materials
Extrinsic self-healing
materials rely on the
released healing agent
which polymerized to
heal the crack.
Intrinsic self-healing
materials rely on the re-
association of non-
covalent bonding including
hydrogen bonding and
electrostatic attractions.

7. Extrinsic Self-Healing Coating
The healing agents were
released to the cracks to
heal the crack.
[1] Huang, M. & Yang, J. Facile microencapsulation of HDI for self-
healing anticorrosion coatings. J. Mater. Chem. 21, 11123 (2011).

8. Intrinsic Self-Healing Coating
The re-association of hydrogen
bonding initiated the self-
healing process.
[2] Phadke, A. et al. Rapid self-healing hydrogels. Proc. Natl.
Acad. Sci. U. S. A. 109, 4383–4388 (2012).

9. Out Materials: VHB 4910
Image source: https://www.tapecase.com/pd/cn/tapes-die-
cuts/1026/1000707/3m-4910-vhb-tape.aspx
VHB 4910 is a double-sided
tape manufactured by 3M
company. Because of its
dielectric property, it has been
studied as actuator and artificial
muscles.

10. Out Materials: Mg Alloys (AZ31)
Image source:
http://www.aist.go.jp/aist_e/latest_research/2010/
20100217/20100217.html
Magnesium alloy is used in
automobile manufactures
because of its high strength
to weight ratio. However,
the low corrosion resistance
has limited its applications.

11. Outlines
Introduction
Objectives
Experiments on VHB 4910
Experiments on the coating
Conclusion

12. Objectives
To determine the self-healing ability of
VHB 4910.
To develop a self-healing coating on the
magnesium alloy substrate.
To understand the self-healing
mechanism of acrylic materials.

13. Outlines
Introduction
Objectives
Experiments on VHB 4910
Experiments on the coating
Conclusion

14. Self-Healing Behavior
Both of the fracture strain
and stress increased with
healing time.

15. Self-healing efficiency
The self-healing efficiency
increased with healing
time.

16. Molecular Chain Diffusion
According to Wool et al.[4],
the true fracture stress after
healing is proportional to
(𝑡)^0.25. This is considered
to be a chain diffusion result.
[4] Y. H. Kim, R. P. Wool, Macromolecules 1983, 16, 1115.

17. Raman Spectrum
We focused on the free and
hydrogen bonded carbonyl
bonds.
Cutting interfaces
Scanning line

18. Hydrogen bonding
The wavenumber decreased
and the full width at half
maximum increased when the
distance is closer to the cut
interface.

19. The Self-healing Mechanism of VHB 4910
Both of the re-association of
hydrogen bonding and the
diffusion of molecular chains
contribute to the self-healing
process of this material.

20. Outlines
Introduction
Objectives
Experiments on VHB 4910
Experiments on the coating
Conclusion

21. Fabrication Process
(PEI/PAA)10
PEI/GO
Ce(NO3)3·6H2O
PEIPAA
Deionized H2O
Deionized H2O
GO
OR
+++++++++
-------- -+++++
① Immerse in
cerium nitrate
solution to deposit
the cerium-based
conversion layer.
② Heating to
evaporate the
residual water
molecules and
partially transform
Ce(III) to Ce(IV).
③ Layer-by-Layer
assembly of the
poly(ethylene mine)
(PEI), graphene
oxide (GO) and
poly(acrylic acid).

22. SEM Images
Immersed in Ce(NO3)3 Heated at 80°C
PEI/PAA without GOPEI/PAA with GO
The scanning electron
microscopy (SEM)
images show the surface
morphologies of different
coated samples.

23. Raman Spectra
The successful deposition
of cerium hydroxide and
cerium oxide.
The partial transform of
cerium hydroxide to
cerium oxide.
The successful deposition
of poly(ethylene imine)
(PEI) and poly(acrylic
acid) (PAA).
The successful deposition
of graphene oxide (GO).

24. Self-Healing Images
PEI/PAA without GO
PEI/PAA without GO
The coating can heal the
scratch in 10 min in the
presence of water.

25. Time
Swelling ratio (PEI/PAA)10 Swelling ratio (PEI/PAA)15
Swelling Ratio
The swelling ratio increased
fast during the first 10 min
of immersion. This result
agrees with the self-healing
behavior in the presence of
water.
10 min

26. EIS (Nyquist Plot)
The graphene oxide
incorporated coating
exhibited the best corrosion
resistance because of its
largest polarization
resistance value.
The polarization resistance
is defined as the difference
between the real impedance
when frequency equals zero
with the solution resistance.
Solution resistance at 𝑓𝑚𝑎𝑥 = 105𝐻𝑧
Real impedance at 𝑓𝑚𝑖𝑛 → 0𝐻𝑧

27. Outlines
Introduction
Objectives
Sample preparation
Sample characterization
Surface morphology
Compositions characterization
Corrosion resistance
Self-healing ability
Conclusion

28. Conclusions
The self-healing efficiency of VHB 4910 increases with the
healing time and healing temperature.
Both of the hydrogen bonding and the chain diffusion
process contribute to the self-healing process.
The PEI/PAA multilayer coating exhibits rapid self-healing
ability in the presence of water.
The graphene oxide can improve the corrosion resistance of
the multilayer coatings.

29. Q?
A.