1. Polymer-Clay Nanobrick Wall Thin Films as Foil Replacements
Morgan A. Priolo, Kevin M. Holder, Laura Bolling, Jaime C. Grunlan*
CHEMICAL & MECHANICAL ENGINEERING
TEXAS A&M UNIVERSITY
COLLEGE STATION, TX 77843
AIChE Annual meeting, Pittsburg, PA– November 1st, 2012

2. Acknowledgements POLYMER NANO COMPOSITES POLYMER NANO COMPOSITES
NANOCOMPOSITES.TAMU.EDU
POLYMER NANO
COMPOSITES

3. Applications Food Packaging Flexible Electronics Pressurized Systems
cryovac.com
Pressurized Systems
Separation Membranes
mitsubishicars.com
Food packaging- longer shelf life, pressurized systems-keep gas in, flex electronics- keep electrical components from being ruined by ogygen, sep membranes- H purification to desalination of water
ornl.gov
Eichie, F. E. et al., J. Appl. Polym. Sci. 2006, 99, 725.
Grunlan, J. C. et alJ. Appl. Polym. Sci. 2004, 93, 1102.
Graff, G. L. et al. Flexible Flat Panel Displays, Crawford, G. P., Ed. John Wiley & Sons, Ltd.: 2005. 3

4. Motivation Metallized Plastic
Thin metal films have been deposited onto polymeric webs for gas barrier since the 1970s.
In 2001 alone, 11 billion sq. meters were used for packaging.
Only 10–100 nm imparts 1000x reduction in permeability.
Major drawbacks:
Not microwavable
Not recyclable
Completely opaque
× 2,000,000
-permeability- rate of oxygen passing through membrane per area per pressure
Graff et. al. In Flexible Flat Panel Displays; Crawford, G. P., Ed.; John Wiley & Sons, Ltd.: 2005, p 57. 4

5. Background Silicon Oxide (SiOx) Barrier Film Polymer Multilayer (PML)
Transparency, microwavability
Cracking, poor adhesion to polymer
Roberts et. al. J. Membr. Sci. 2002, 208, 75.
Leterrier, Y. Prog. Mater. Sci. 2003, 48, 1.
Polymer Multilayer (PML)
Packaging solution for electronics
Complicated processing, cracking (better than SiOx)
Affinito et. al. Thin Solid Films 1996, 291, 63.
Graff et. al. In Flexible Flat Panel Displays; Crawford, G. P., Ed.; John Wiley & Sons, Ltd.: 2005, p 57.
Use “extreme conditions”
Bulk Composite
Poor transparency
Relatively low barrier
Nazarenko et. al. J. Polym. Sci. B: Polym. Phys. 2007, 45, 1733. 5

6. Background
Property comparison of SiOx, polymer multilayer and layer-by-layer films
Layer-by-layer assembly can produce super gas barrier films without any of the drawbacks of previously mentioned techniques!
1 Inagaki, N.; Tasaka, S.; Hiramatsu, H., Journal of Applied Polymer Science 1999, 71, 2091.
2 Affinito, J. D.; Gross, M. E.; Coronado, C. A.; Graff, G. L.; Greenwell, E. N.; Martin, P. M., Thin Solid Films 1996, 291, 63.
3 Jang, W. S.; Rawson, I.; Grunlan, J. C., Thin Solid Films 2008, 516, 4819. 6

7. Ploehn, H. J.; Liu, C. Y., Ind. Eng. Chem. Res. 2006, 45, 7025.
Thin Film Materials
Sodium Montmorrilonite Clay (MMT):
(Cloisite-Na+ from Southern Clay)
Platelet structure (~1nm thick)
Aspect ratio (ℓ/d) of 100–1000
1.0 wt.% suspension
Negatively charged in water
Ploehn, H. J.; Liu, C. Y., Ind. Eng. Chem. Res. 2006, 45, 7025.
Branched Polyethylenimine (PEI):
(Purchased from Sigma–Aldrich)
Mw = 25,000 g/mol
0.1 wt.% at pH = 10
Positively charged in water
Cool materials
Poly(acrylic acid) (PAA):
(Purchased from Sigma–Aldrich)
Mw = 100,000 g/mol
0.2 wt.% at pH = 4
Negatively charged in water
Priolo, M. A.; Gamboa, D.; Holder, K. M.; Grunlan, J. C., Nano Letters 2010, 10, 4970. 7

8. Layer-by-Layer Assembly
Repeat until desired # of layers are deposited
1 Bilayer
Substrate
̶ ̶ ̶ ̶
Rinse
Dry
Ambient Processing
Tunable Properties
Nanoparticle Control
Priolo, M. A.; Gamboa, D.; Grunlan, J. C. ACS Applied Materials & Interfaces 2010, 2, 312.
Decher, G. Science 1997, 277, 1232. 8

9. Layer-by-Layer Assembly
2D Robot
3D Robot
Lbl process- “homemade robot”
Gamboa, D.; Priolo, M. A.; Ham, A.; Grunlan, J. C.,
Rev Sci Instrum 2010, 81,
Jang, W. S.; Grunlan, J. C., Rev Sci Instrum 2005, 76, 9

10. Film Thickness Delayed exponential growth
Priolo, M. A.; Gamboa, D.; Holder, K. M.; Grunlan, J. C., Nano Letters 2010, 10, 4970. 10

11. Film Composition 26.2% MMT 36.7% MMT 48.6% MMT 53.7% MMT
Clay % decreases as film is grown, exponential growth from polymer layers, mass is exponential also
Priolo, M. A.; Gamboa, D.; Holder, K. M.; Grunlan, J. C., Nano Letters 2010, 10, 4970. 11

12. Optical Clarity > 95% Transparent
Very high transparency lends well to foil replacement
> 95% Transparent
Priolo, M. A.; Gamboa, D.; Holder, K. M.; Grunlan, J. C., Nano Letters 2010, 10, 4970. 12

13. Super Gas Barrier Without PAA, this level of barrier
Bare PET
QLs
OTR (cc/(m2·day·atm))
Film Thickness (nm)
Film Permeability
(10-16 cc·cm/(cm2·s·Pa)) 2
8.169
16.1 3
2.341
28.3 4
≤0.005
50.9 ≤ 5
<0.005
82.6
<
Lowest reported permeability for a
polymer – clay thin film!
Without PAA, this level of barrier
requires at least 24 PEI/MMT BLs.
Morgan A. Priolo, Kevin M. Holder, Daniel Gamboa, and Jaime C. Grunlan Langmuir 2011 27 (19), 12106
SUPER GAS BARRIER!! 3 orders of magnitude increase from bare to 4 QL, nanobrick wall structure, 24 BL=120nm
Priolo, M. A.; Gamboa, D.; Holder, K. M.; Grunlan, J. C., Nano Letters 2010, 10, 4970. 13

14. Nanobrick Wall Structure
80 nm
Mention discrete layers
20 nm
5QL on 5-mil PS
Priolo, M. A.; Gamboa, D.; Holder, K. M.; Grunlan, J. C., Nano Letters 2010, 10, 4970. 14

15. Humidity & Crosslinking (7QL)
Thermal cross-linking improves humid barrier performance of neat thin film by 33%
One problem with lbl from aqueos solutions is diminished OTR at high RH, crosslinking improves this by 33% (7QL film)
Priolo, M. A.; Gamboa, D.; Holder, K. M.; Grunlan, J. C., Nano Letters 2010, 10, 4970. 15

16. Conclusion & Future Work
Transparent QL films made using LbL deposition
4 QL film has lowest reported permeability for a clay-polymer film
Need to evaluate gas separation
Will work to eliminate humidity sensitivity
-optimize clay spacing 16

17. Questions?