The document discusses Atomic Layer Deposition (ALD) and its application in creating polymer-inorganic core-shell nanofibers. Specifically, it summarizes a study where nylon 6,6 nanofibers produced by electrospinning were coated with zinc oxide using ALD to create flexible nylon-ZnO core-shell nanofiber mats. Characterization techniques like SEM, TEM, EDX, XPS and XRD were used to analyze the core-shell structure and properties. The nanofiber mats exhibited photocatalytic activity and could potentially be used as filter materials for water purification or organic waste treatment.

1. Atomic Layer Deposition (ALD)
Student: Chinmayananda Gouda
Recommender: Prof. Wha-Tzong Whang
Dept. of Materials Science and Engineering, National Chiao Tung University
Jan.7, 2014

2. Outline
1
About ALD
2
Application (ACS , journal )
3
Approaches
Conclusion

3. What is ALD?
I.
ALD (Atomic Layer Deposition)
II. Deposition method by which precursor gases or vapors are alternately
pulsed on to the substrate surface.
III. Precursor gases introduced on to the substrate surface will chemisorb or
surface reaction takes place at the surface
IV. Surface reactions on ALD are complementarity and self-limiting
1/13

4. Polymer-Inorganic Core-Shell Nanofibers by Electrospinning and ALD
Polymer−inorganic core−shell nanofibers were produced by two-step approach;
electrospinning and atomic layer deposition (ALD).
First, nylon 6,6 (polymeric core) nanofibers were obtained by electrospinning, and
then zinc oxide (ZnO)(inorganic shell) with precise thickness control was
deposited onto electro spun nylon 6,6 nanofibers using ALD technique.
Nylon 6,6 (polymeric core) nano-fiber:
Fatma Kayaci, Cagla Ozgit-Akgun, Inci Donmez, Necmi Biyikli,and Tamer Uyar, "Polymer−Inorganic Core−Shell Nanofibers by Electrospinning and
Atomic Layer Deposition: Flexible Nylon−ZnO Core−Shell Nanofiber Mats and Their Photocatalytic Activity", ACS Appl. Mater, 2012.
2/13

5. Approaches
Core−shell nylon 6,6-ZnO nanofibers mat can be a very good candidate as a
filter material for water purification and organic waste treatment because of
their photo catalytic properties along with structural flexibility and stability.
The reason, the development of flexible nanofibrous membranes or textiles
having photocatalytic properties is still on demand for self-cleaning and water
purification and waste treatment.
3/13

6. Electrospinning and ALD ( Atomic Layer Deposition )
4/13

7. Solvent and Fiber composition
Sample
8%-nylon
6,6/FA NF
5%-nylon
6,6/HFIP NF
8%-nylon
6,6/HFIP NF
Solvent
FA
HFIP
HFIP
Concentration
of nylon 6,6
(% w/v)
8
5
8
Viscosity
(Pa`s)
0.0228
0.115
0.24
Average fiber
diameter
before ALD
(nm)
80 ± 15
240 ± 45
650 ± 140
Average fiber
diameter after
ALD (nm)
Fiber
morphology
305 ± 50
bead-free
nanofibers
470 ± 70
bead-free
nanofibers
835 ± 320
bead-free
nanofibers
5/13

8. SEM images
6/13

9. EDX spectrum
EDX spectrum of nylon 6,6-ZnO core–shell nanofibers (8%-nylon 6,6/HFIP-ZnO NF)
chemical maps of C, Zn, and O
7/13

10. TEM Images and SAED pattern
8%-nylon 6,6/FA-ZnO
8%-nylon 6,6/HFIP-ZnO
5%-nylon 6,6/HFIP-ZnO
SAED pattern of nylon 6,6-ZnO
8/13

11. XPS Scan and TGA Thermograms
Zn 2p high-resolution XPS scan of core–shell nylon 6,6ZnO nanofibers (8%-nylon 6,6/FA-ZnO NF)
TGA thermograms of pristine nylon 6,6 and
core–shell nylon 6,6-ZnO nanofibers.
9/13

12. XRD patterns
XRD patterns of pristine nylon 6,6 and core–shell nylon 6,6-ZnO nanofibers
10/13

13. UV–vis spectra of the Rh–B solution
11/13

14. SEM image after UV irradiation
12/13

15. Conclusion
The core−shell nylon 6,6-ZnO nanofibers mats can be quite applicable as a
filtering/membrane material for treatment of organic pollutants for water purification
due to their efficient photocatalytic properties, structural flexibility and stability
ALD is a relatively low-temperature process providing ultimate
conformality, therefore, three dimensional, polymeric nanofiber templates can easily be
coated by ALD of inorganic materials for producing flexible nanofiber mats.
13/13

16. I welcome your questions,
suggestion, comments!