This document provides an outline and background for a PhD thesis on engineering nano-cellulose films and composites via spray coating. The introduction discusses applications and gaps in knowledge regarding nano-cellulose. The structure of the PhD will involve developing a flexible spray coating process to prepare strong, dense nano-cellulose films and investigate their barrier properties. Chapters will explore controlling film properties, recycling smooth films, adding inorganic nanoparticles, and tuning surface roughness. The research aims to develop a scalable technology for applications like printed electronics using a flexible laboratory spray coating method.

1. S.Kirubanandan
Ph.D. Student
7th September 2018, BAMI Industrial Chapter, Bioprocessing Resource Institute of Australia,
Department of Chemical Engineering, Monash University
ENGINEERING NANO-CELLULOSE FILMS AND
ITS COMPOSITIES
VIA
SPRAY COATING
Supervisors: Warren Batchelor, Gil Garnier and
Swambabu Varanasi

2. OUTLINE
2
Introduction
Research gaps
Structure of PhD
Conclusion

3. Background
3

4. INTRODUCTION
Isogai et al. Nanoscale,2011,3, 71-85
4

5. APPLICATIONS OF NANOCELLULOSE
Packaging1 Oil and water separation2 Photo catalyst3
Gels for
Biomedical
Applications5
Nanocellulose
based composites6
Nanocomposites as High
Performance Barrier7
Membrane4
1. K.Shanmugam et al, Cellulose, 2017,24, 7, 2669–2676.
2. Z. he et al, RSC Adv., 2016, 6, 21435-21438
5. Mendoza et al, J Colloid Interface Sci. 2018 1;509:39-46.
7. U.M. Garusinghe et al, Colloids and Surfaces A,540, 2018,233-241.
3. U.M. Garusinghe et al, Scientific Reports, 8, 2306 (2018)
4. V. Swambabu et al , Chemical Engineering Journal 265(1) 2015.
5

6. GAPS IN KNOWLEDGE
6
1. Can we spray NC on a impermeable surface?
2. Can we the tailor properties of NC film with the process
variables?
3. Can we recycle the NC film?
4. Do nanoparticles affect on the properties of NC film?
5. How do we control/minimize the smoothness of the film?

7. STRUCTURE
7
Application
of Spray
Coating
Process and
Sustainability
Concept

8. 8
CH 2. RAPID PREPARATION OF NC FILMS
Spray system Spray coated NC film
A
B
SS Plate

9. 9
CH 2. RESULTS
0
50
100
150
200
250
300
0
50
100
150
200
250
0.8 1.3 1.8 2.3
BasisWeighting/m2
Concentration of nanocellulose in wt%
Basis Weight Vs Suspension
Concentration
Thickness Vs Suspension
Concentration
Thicknessinµm
Rough
Smooth
SEM Optical SEM
Profilometry

10. 10
CH 2- OUTCOME
 Rapid laboratory scale method to prepare NC film using
spray coating
 Tailorable basis weight and thickness of the NC film

11. 11
Spray system
Multiple NC film
Impermeable
Surface
Nanocellulose
CH 3. FLEXIBLE SPRAY COATING PROCESS
PeelingSpraying

12. PROPERTIES OF NC FILMS
12
0
50
100
150
200
250
300
0 50 100 150 200 250
Thickness(μm)
Basis weight ( g / m2 )
Series 1 - Concentration effects
Series 2 - Conveyor velocity
effects
Series 3 - Modified
Configuration
Vacuum Filtration
600
650
700
750
800
850
900
0 50 100 150 200
ApparentDensity(Kg/m3)
Basis weight ( g / m2 )
Series 1 - Concentration effects
Series 2 - Conveyor speed effects
Series 3 - modified configuration
Vacuum Filtration

13. MECHANICAL PROPERTIES
13
0
10
20
30
40
50
60
70
80
90
100
0 50 100 150 200 250
TensileIndex(Nm/g)
Basis weight ( g / m2 )
Series 1 - Concentration
effects
Series 2 - Conveyor velocity
effects
Series 3 - Modified
Configuration
Vacuum Filtration
0
2
4
6
8
10
12
14
16
18
0 50 100 150 200
Young'sModulus(GPa) Basis weight ( g / m2 )
Series 1 - Concentration
effects
Series 2 - Conveyor velocity
effects
Series 3 - Modified
Configuration
Vacuum Filtration

14. CHAPTER 3- OUTCOME
14
 A flexible spraying process for a strong, dense and robust
NC films
 Increase in uniformity and strength of NC film.

15. Barrier materials
Wax
Aluminium
Plastics
Limitation:
Poor barrier
properties
15

16. Nanocellulose – Potential Barrier
• Bio degradable
• Non toxic
• Extreme High Surface Area
• Crystallinity
• Tuneable surface for
functionalization
Martin Hubbe et al, Nano cellulose in Packaging: A Review, Bio Resources 12(1), 2143-2233.
16

17. Overview of Barrier Materials
Aulin and Lindström, Biopolymer Coatings for Paper and Paperboard, John Wiley & Sons, Ltd, 2011, pp. 255-276
17

18. CH. 4 RECYCLING OF SMOOTH NC FILMS
18
Before Recycling
After Recycling

19. BARRIER PROPERTIES OF NC FILM
19
Spray coated NC Film < 0.003 µm/Pa.S
Recycled sheet (Vaccum Filtration) - 0.0045 µm/Pa.S
0
2E-11
4E-11
6E-11
8E-11
1E-10
1.2E-10
1.4E-10
1.6E-10
0.6 0.65 0.7 0.75 0.8 0.85 0.9
Watervapourpermeability
g.m-1.s-1Pa-1
Apparent Density (g.m-3 x 10-6 )
Spray coating
Vaccum Filtration
Recycled sheet
Air Permanence Water vapour
Permeability

20. CH 4 -OUTCOME
20
 Low permeance of air and water vapour
 Retained 80% of the tensile strength
 Recycled NC film shows limited reductions in barrier
performance
 Pathway for sustainability

21. Effect of Inorganics Addition
Müller, Kerstin (2017). Nanomaterials. 7. 47. 10.3390/nano7040074.U.M. Garusinghe et al, Colloids and Surfaces A,540, 2018,233-241.
21

22. Preparation of Nanocomposite via spraying
Nano clay Solution and
Nanocellulose
Preparation
Nanocellulose
Nano clay –
Nanocellulose (Raw
Diacel KY 100S)
Composites
Nano clay –
Nanocellulose
(Homogenised 2 passes)
Composites
Without Homogenization
With Homogenization
Disintegrator Spray Coating
NC- Closite Na++ (MMT)
Suspension
2 Pass
˜ 800-1000 Bar
22

23. Spray Coated Nanocomposite
Closite Na++ ( Natural Bentonite MMT)- Nanocellulose Nanocomposite
23

24. Effect of Nano clay addition on WVP ( After Homogenization)
R² = 0.8283
R² = 0.9988
R² = 0.9975
R² = 0.9772
0
0.5
1
1.5
2
2.5
3
3.5
4
0 5 10 15 20 25 30 35
Watervaporpermeabilityx1011(g/Pa.s.m)
Nanoclay Loading (%)
Closite Na+
Nanocomposite Na via Vaccum Filtration
Nanocomposite Na via Vaccum Filtration after Homo
Nanocomposite via spraying after Homo
24

25. SEM MICROGRAPHS
Spray Coated NC film (Homo) Spray Coated 30 % MMT –NC (Homo) Composites
Spray Coated 30 % MMT –NC (unhomo) CompositesSpray Coated NC film (unhomo)
25

26. Works to be performed
• Surface Roughness at nanoscale thro Optical
Profilometry
• Surface Roughness at micro scale via Parker Print
Surface Instrument
• AFM Investigation of Nanocomposites
26

27. CH. 6 –TUNING SURFACE ROUGHNESS
27
 Objective: Tuning surface
roughness
 what parameters controls the
roughness of the NC films
 Base surface (or)
 Fibre Diameter
 To prepare smooth nanocellulose
films
Super Mirror Stainless
Steel Plate
Silicon wafers
Normal Stainless Steel
Plate
Aluminium Foil
Different Base surface

28. 28
APPLICATION OF SMOOTH NC FILMS
 NC films for printed
electronics
 Smoothness on printing of
RFID circuits on the NC film
Use of nanocellulose in printed electronics: a
review (Fanny Hoeng et al., 2016)

29. 29
CONCLUSION
• Flexible and Rapid Process
• Comparable Properties
• A scalable technology

30. ACKNOWLEDGEMENT
• Assoc Prof. Warren Batchelor and Prof. Gil Garnier
• Dr. Swambabu Varanasi, Asst. Prof, IIPE, India.
• Dr. Vikram Raghuwanshi, Research Fellow, BIOPRIA,
Monash Uni.
• Student friends and Staff members at BioPRIA
30

31. Thank you very much