1. Coating Techniques and Their Applications
Dimitri Eigel
Susann Kintzel (Schulze)
Claudia Schenk
Christina Schneidermann
Jakob Zessin
Dresden, 3 and 10 July 2014

2. Coating Techniques and Its Application
Schedule
Date
Presenter
Topic
03.07
Christina Schneidermann
Dip-coating and Spin-coating
Claudia Schenk
Chemical Vapor Deposition
Susann Kintzel
Electrospinning
10.07
Jakob Zessin
Self-healing polymers
Dimitri Eigel
Plasma-Electrolytic-Oxidation
Coating Techniques and Its Application

3. Self-healing polymers
Jakob Zessin
Dresden, 10 July 2014

4. Self-healing polymers
Outline
Introduction
Classification
Intrinsic self-healing
Extrinsic self-healing
Outlook
TU Dresden, 10 July 2014
Self-healing polymers

5. Self-healing polymers
Introduction
Motivation
polymers are widely used
long-term stability problematic
Macroscale cracks leads to loss of functionality
repair cracks at miscro-, mesoscale
biological heal small damage by itself
Application beyond the scope of coatings
Zwaag, S. v.d. (ed.); Self Healing Materials, Springer: Dordrecht, 2007,
TU Dresden, 10 July 2014
Self-healing polymers

6. Self-healing polymers
Classification
Intrinsic self-healing
healing ability is in the polymer itself
external stimuli are required to start healing
Extrinsic self-healing
polymer composites, healing agent is pre-embedded
automatic healing, no external stimuli required
Yuan, Y.C. et al.; Express. polym. lett. 2008, 2,
TU Dresden, 10 July 2014
Self-healing polymers

7. Intrinsic self-healing
self-healing motives
physical (heating to glass transition)
chemical (revesible chemical reactions)
supramolecular (rotaxane, figure)
limitation
viscous reflow vs resistance to flow
transport of healing agent to damaged areas
Self-healing rotaxane
figure: article “Materialien, die sich heilen“ ( )
Zwaag, S. v.d. (ed.); Self Healing Materials, Springer: Dordrecht, 2007,
TU Dresden, 10 July 2014
Self-healing polymers

8. Extrinsic self-healing
Encapsulation of healing agent
in capsules: dicylopentadiene
matrix: epoxy resin
one healing in the same area
many parameters for agent and capsule shell
scheme of self-healing
White, S. R. et al.; Nature, 2001, 409,
TU Dresden, 10 July 2014
Self-healing polymers

9. Extrinsic self-healing
Microvascular system with healing agent
biomimetics from blood circulation
system printed with fugitive ink, which is later removed
more healing processes at the same area
coating
excess of healing agent
Epoxy resin with microvascular system
Toohey, K.S. et al.; Nat. Mater. 2007, 6,
TU Dresden, 10 July 2014
Self-healing polymers

10. Self-healing polymers
Outlook
no everlasting organic Polymer (coating)
LG G Flex
Nissan Scratch Shield
a lot of research is still necessary
( )
article: LG G Flex ( )
TU Dresden, 10 July 2014
Self-healing polymers

11. Thank you for your attention!
TU Dresden, 10 July 2014
Self-healing polymers

12. Plasma-Electrolytic Oxidation
Dimitri Eigel
Dresden, 10 July 2014

13. Plasma-Electrolytic-Oxidation
Outline
1 Basics of Plasma-Electrolytic-Oxidation
2 Motivation
3 Example of Plasma-Electrolytic-Oxidation
4 Applications of PEO
5 Advantages of PEO
TU Dresden, 10 July 2014
Plasma-Electrolytic-Oxidation

14. Basics of Plasma-Electrolytic-Oxidation
Basics of PEO
Novel surface modification technique (PEO, MAO or ANOF)
Surface modification method for light metals (Ti, Mg, Al)
Formation of dense metal oxides on the surface
An alkaline watery electrolyte is often used
Electrolysis often performed with alternating current
TU Dresden, 10 July 2014
Plasma-Electrolytic-Oxidation

15. Plasma-Electrolytic-Oxidation
Motivation
Motivation
Establishing of a Plasma-Electrolytic-Oxidation for light metal alloys
Creation of non-corrosive or biologically active surfaces
Potential alternative for conventional anodizing
F. C. Walsh, C. T. J. Low, R. J. K. Wood, K. T. Stevens JA, A. R. Poeton and AR. Transactions of the Institute of Metal Finishing. 2009;87:
TU Dresden, 10 July 2014
Plasma-Electrolytic-Oxidation

16. Basics of Plasma-Electrolytic-Oxidation
Schematic overview
Three significant processes:
Growth of oxide layer coating
Micro spark discharge
Discharge and release of gas
Discharge channels cause oxygen ionisation (106 und 108 V/m)
and H. Dong, Woodhead Publishing Limited, 2010
TU Dresden, 10 July 2014
Plasma-Electrolytic-Oxidation

17. Basics of Plasma-Electrolytic-Oxidation
Schematic Overview
local temperatures + pressures of 2∙104 °C
and 102 MPa
within 10-6 s
und H. Dong, Woodhead Publishing Limited, 2010
TU Dresden, 10 July 2014
Plasma-Electrolytic-Oxidation

18. Example of Plasma-Electrolytic-Oxidation
Set up and Parameters
20 minutes of electrolysis
Watery electrolyte 0,1 M NaOH
Galvanostatic working method
Use of direct current (power source max. 600 V)
Used current densities 0,05 / 0,1 / 0,5 A∙cm-2
TU Dresden, 10 July 2014
Plasma-Electrolytic-Oxidation

19. Example of Plasma-Electrolytic-Oxidation
crater and volcano like form at high current densities, e.g. 0,5 A∙cm-2
average pore diameter
ca. 1-4 µm
TU Dresden, 10 July 2014
Plasma-Electrolytic-Oxidation

20. Example of Plasma-Electrolytic-Oxidation
coral like form at current density 0,1 A∙cm-2
average pore diameter
0,5-2 µm
TU Dresden, 10 July 2014
Plasma-Electrolytic-Oxidation

21. Example of Plasma-Electrolytic-Oxidation
coat thickness increases with higher current density
max. coat thickness ca µm
TU Dresden, 10 July 2014
Plasma-Electrolytic-Oxidation

22. Plasma-Electrolytic-Oxidation
Applications of PEO
Corrosion resistance
Biomedical
Consumer electronics
Aerospace
Cookware
TU Dresden, 10 July 2014
Plasma-Electrolytic-Oxidation

23. Plasma-Electrolytic-Oxidation
Advantages of PEO
Advantages
Coating properties that improve abrasion and corrosion resistance
Set up, equipment and test procedure not complicated
Low implementation costs
Ecologically harmless (non-toxic emissions)
TU Dresden, 10 July 2014
Plasma-Electrolytic-Oxidation

24. Thank you for your attention!
TU Dresden, 10 July 2014
Plasma-Electrolytic-Oxidation