Overview of Spray Coated Nanocellulose Films

1. Bioresource Processing Institute of Australia (BioPRIA)
Department of Chemical Engineering
Monash University
SPRAY COATED NANOCELLULOSE FILMS:
PRODUCTION, CHARACTERISATION AND
APPLICATION
Pre Submission Seminar Report
Kirubanandan Shanmugam
kirubanandan.shanmugam@monash.edu
Supervisor: Assoc. Prof. Warren Batchelor
Associate Supervisor: Prof. Gil Garnier
Department of Chemical Engineering, Monash University.
7th
February 2019

2. 2
Contents
1. Overview of the final stages of my PhD Works .............................................................................3
2. Thesis Structure ..............................................................................................................................4
2.1. Chapter 1 – Introduction and Literature Review: .......................................................................4
2.2. Chapter 2 - Rapid Preparation of smooth nanocellulose films using spray coating....................4
2.3. Chapter 3- Flexible Spray Coating Process for Smooth Nanocellulose Film Production...........5
2.4. Chapter 4- Smooth nanocellulose films as air and water vapour barrier: a sustainable
alternative to polyolefin packaging.........................................................................................................6
3. Current Progress in Thesis Writing.............................................................................................8
3.1. Chapter 5- Flexible Process for developing MMT –Nanocellulose composite via spraying......8
3.2. Chapter 6 – Tuning Surface smoothness of Nanocellulose Film via spray coating....................8
3.3. Chapter 7 – Conclusion and Future Perspective .........................................................................9
3.4. Manuscript Planned .........................................................................................................................9
3.5. Thesis Completion Timeline..........................................................................................................10
3.6. Contribution...................................................................................................................................10
4. Research Output....................................................................................................................10
4.1. Publication ............................................................................................................................10
4.2. Manuscript Communicated...................................................................................................10
4.3. Other papers not included in the main thesis. .......................................................................11
4.4. Full Refereed Conference Proceedings.................................................................................11
4.5. Conference abstract...............................................................................................................11
5. ANNEXURE.........................................................................................................................11

3. 3
1. Overview of the final stages of my PhD Works
The thesis reports a rapid and flexible spraying process to produce nanocellulose (NC) films
and NC based composites as sustainable barrier materials and novel smooth substrates. The reviewed
literature reveals the advantages and disadvantages of existing methods such as solvent casting, vacuum
filtration and spraying on nylon fabric surface to prepare NC films and nanocomposites. The review
further addresses the NC spraying on impermeable surfaces and its potential for developing high-
performance barrier materials, composites and smooth films. The literature review showed the lack of
a rapid process to prepare the NC films and nanocomposites in a few seconds to minutes in an energy
efficient way. This thesis advances the production, characterization and application of NC films and
its composites via spraying of NC suspension on a smooth surface.
Figure 1– Outlines of my doctoral program and its structure
Concept
Chapter 1-
Literature Review
Chapter -2 -Spray
Coating
Process and
Sustainability
Chapter 3 - Full
Spray Coating
Process
Chapter 4 -
Recyclability and
Barrier Performance
Applications of
Spray Coating
Chapter 5-
Nanocomposite
Chapter 6- Smooth
Nanocellulose film
Thesis
Outcome

4. 4
2. Thesis Structure
My thesis is structured into six major components which are the major chapters of my thesis.
Each chapter is briefly described here with important highlights and five of these chapters will be
published as an individual research paper in peer-reviewed journals. Figure 1 gives the structure of PhD
thesis, highlighting the objective of each chapter. The spray coating of nanocellulose is used to prepare
the nanocellulose film, nanoclay- NC composite film and an optimized smooth nanocellulose film. Each
product has a specific application, especially barrier materials and other applications like printed
electronics.
2.1. Chapter 1 – Introduction and Literature Review:
Chapter 1 is divided into introduction and literature review on NC film preparation and its limitations.
In the Introduction, the production of NC films and nanocomposites is discussed. Notably, the
application of NC and its advantages in replacing the synthetic polymers are briefed. The literature
review gives a critical review on nanocellulose film preparation, the spraying of nanocellulose on
permeable and impermeable surfaces, its advantages and disadvantages, and other forms of NC film
production would be mentioned. Additionally, Nanocellulose as sustainable barrier materials and the
need for improvements in its barrier performance, with a particular focus on nanocellulose composites,
have been addressed. The potential applications for nanocellulose film and its composites as barrier,
composites, smooth films and membranes will also be discussed.
Writing - 40% Complete
2.2.Chapter 2 - Rapid Preparation of smooth nanocellulose films using spray coating
This chapter focuses on a novel concept on spraying nanocellulose on a polished stainless steel
plate to prepare a smooth NC film. The formed spray coated NC on the steel plate can be dried and
peeled easily from the stainless steel plate. Figure 2 shows a good uniformity of spray coated NC film
via thickness mapping. This is an alternative to vacuum filtration, which has the drawbacks of high
drainage time and difficulties arising from the filter and a hard to handle film.
Figure 2 – Thickness distribution of NC films via spray coating and vacuum filtration

5. 5
By this method, the NC films with a basis weight per unit area ranging from 50 to 200 g/m2
could be prepared, with the basis weight easily controlled from the suspension solids concentration.
Spraying nanocellulose on the polished impermeable surface yields the film with surface smoothness
having a RMS value of 389 nm over a 1 cm2
inspection area. When comparing with vacuum filtration,
which requires at least 10 mins to form a film, the operating time for spraying of nanocellulose on the
surface is less than 1 minute and independent of suspension consistency. This work has been published
Cellulose journal and the published paper is attached to this report (Shanmugam, 2017).
2.3.Chapter 3- Flexible Spray Coating Process for Smooth Nanocellulose Film
Production
This chapter mainly explores the conversion of concept of chapter 2 into the full-fledged
process of spraying nanocellulose on the stainless steel platem the effects of process variables on the
properties of NC films and the comparison with the film via vacuum filtration. This chapter especially
addresses the bulk properties, strength and surface properties of the spray coated nanocellulose films.
Additionally, the experimental set up is modified and optimised suspension concentration to enhance
the uniformity of spray coated film and its strength. Figure 3 and 4 shows strength and uniformity of
spray coated NC film. Film uniformity was also noticeably dependent on the spraying process
especially the configuration of the experimental set up and other parameters such as suspension solid
concentration and the velocity of the conveyor.
Figure 3– Tensile Index of the spray coated NC film
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

6. 6
VF-NC Film 1.75 Wt.% SC- NC
Film 1
1.72 Wt.% SC-NC
Film 2
Figure 4 - Paper formation test for spray coated NC film prepared via modified configuration
The most uniform films produced by spraying also had a tensile index comparable to that of
films produced by vacuum filtration. The research shows that the properties of the films produced by
spraying can be much more easily tailored to the required application than producing the films via
vacuum filtration. This work has been published Cellulose journal and the published paper is attached
to this report (Shanmugam, 2018).
2.4. Chapter 4- Smooth nanocellulose films as air and water vapour barrier: a
sustainable alternative to polyolefin packaging
This chapter focuses on the sustainability and recyclability of spray coated NC films and the
barrier performance of spray coated nanocellulose films as a potential replacement for synthetic barrier
materials. This research also investigates the recyclability of spray coated NC films after following a
standard recycling protocol. Nano-cellulose films, created via spraying, were evaluated for barrier
performance and strength and were recycled into similar NC film via vacuum filtration. This chapter
explores a sustainable pathway to producing barrier films. .
Figure 5- Mechanical performance of Virgin and Recycled Film.
20
30
40
50
60
70
80
90
100
110
80 90 100 110 120 130
TensileIndexinNm/g
Basis Weight in g/m2
Virgin NC Film-Instron Method
Recycled NC film -Instron Method
Virgin NC film -Zero span
Recycled NC film - Zero Span

7. 7
Virgin Fibres Recycled Fibres
0 50 100 150 200 250 300 350
0
5
10
15
20
25
30
35
Bin
Fibre diameter in nm
Virgin NC Fibres
0 50 100 150 200 250
0
5
10
15
20
25
30
Fibre Diameter in nm
Bins
Recycled NC Fibre
Figure 6 - Scanning Electron Micrograph of NC before and after recycling.
Figure 5 and 6 confirm the strength of virgin and recycled NC film and the diameter of NC
fibres, respectively. Due to poor hydrogen bonding between nanofibrils and hornification, a drop in
strength of recycled fibres was observed. The formation of agglomeration due to poor breakdown of
fibre during recycling could decrease barrier performance. The retained strength and barrier properties
and facile re-processability of the product promise a sustainable and recyclable alternative to
conventional polyolefin packaging. This provides a very attractive opportunity for the packaging
industry. This paper has been sent to Sustainable Materials and Technologies. A revised version after
refereeing is now under review at the journal.

8. 8
3. Current Progress in Thesis Writing
3.1. Chapter 5- Flexible Process for developing MMT –Nanocellulose composite
via spraying
The nanocomposite from nanocellulose and MMT (Sodium Bentonite) via a flexible spray
coating process is developed. The effect of nanoclay (MMT) addition and homogenization on
mechanical and barrier properties of the nanocomposite are studied. Additionally, the interaction of
MMT with nanocellulose was evaluated as a function of MMT loading in the nanocomposite and size
of the cellulose fibrils after high-pressure homogenization. Critical issues to be addressed include the
structure size and orientation of the nanoclay within the nanocellulose matrix and the relationship to
barrier performance. Figure 7 shows the water vapour permeability of spray coated nanocomposites.
This work is the fifth chapter of my thesis.
Figure 7 – Water vapour permeability of spray coated nanocomposite
Work (experimental) : 100 % complete, Writing: 100% complete
Review status: First draft has now been completed and reviewed.
3.2. Chapter 6 – Tuning Surface smoothness of Nanocellulose Film via spray coating
This chapter explores another application of spray coating to produce smooth nanocellulose
films and focuses on engineering its surface smoothness. This smoothness of the nanocellulose film
played a major role in the performance of the material in the fabrication of various cellulose based
functional materials such as printed electronics, designing of bioactive papers as diagnostics, cellulose-
based Transformer and solar panel, fabrication of Organic LED with smooth nanocellulose film, and
the development of piezoelectric sensors and nanocellulose based transistors. Spraying nanocellulose
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)
MMT Loading (%)
Closite Na+
Nanocomposite Na via Vaccum Filtration
Nanocomposite Na via Vaccum Filtration after
Homo
Nanocomposite via spraying after Homo

9. 9
on the surfaces with low to high surface roughnesses was used to quantify the factors controlling the
surface smoothness/roughness of the NC film. The factors that control the surface roughness and
uniformity of nanocellulose film, including nanofibre diameter, substrate surface roughness and
processing conditions, are investigated and given as the 6th
chapter of the thesis. Very smooth films
will generate an extremely thin surface layer that is highly impermeable and thus the performance of
these films as membranes will be also be investigated.
Work (experimental): 80% complete (20% Incomplete – AFM and SEM).
Writing: 10% complete ( the manuscript outline has been finished)
3.3. Chapter 7 – Conclusion and Future Perspective
This chapter explores the advantages of spray coating as a flexible process to manufacture smooth
nanocellulose films and nanocomposites and addresses its limits and discusses the prospects for scaling
up into an industrial scale. The thesis is then concluded with future applications of spray coating in
material processing and development.
Writing: 0% complete
3.4. Manuscript Planned
• Kirubanandan Shanmugam, Maisha Maliha, Vikram Singh Raghuwanshi, Swambabu Varanasi,
Gil Garnier, Warren Batchelor, “ Flexible Process to produce Nanocellulose –Montmorillonite
Composite via Spray Coating, Planned to communicate to Composite Science and Technology
• Kirubanandan Shanmugam, Humayun Nadeem, Christine Browne, Gil Garnier and Warren
Batchelor, “Engineering the smoothness of nanocellulose film via spraying”, Planned to
communicate to Surface and Coating Technology.

10. 10
3.5. Thesis Completion Timeline
Chapters in Thesis Expected Time of finishing
Chapter 1 : Introduction and Literature Review Jan 2019 (31st
Jan 2019)1
Chapter 2 : Concept Completed and Published
Chapter 3 : Full Process Completed and Published
Chapter 4 : Sustainability Revised Manuscript submitted
Chapter 5 : Application 1 First Draft Completed3
and Commented
Chapter 6 : Application 2 In Progress and will be completed by Jan 2019
Will be drafted rough manuscript4
in Jan 2019
Chapter 7: Conclusion To be written5
Formatting Thesis 1-2 month
1. 15 days to 30 days required to answer the comments raised by supervisors and change the draft as per supervisors expectations.
2. Chapter 3 revised and resubmitted to Journal
3. Chapter 4 is the first review completed and 1 month required to make the draft as per supervisor expectations.
4. 1 month is required to finish chapter 5
5. 1 month is required to format the thesis with writing conclusion part.
3.6. Contribution
This work enhances the scope of nanocellulose as high-performance barrier materials and a potential
alternative for synthetic plastic packaging. Through spray coating, the operation time for forming
nanocellulose film is less than a minute and this method is potential for fast production of multiple
sheets when compared with vacuum filtration. Spraying of nanocellulose with clays or without clay on
the polished impermeable surface produced the films with a shiny surface and which could play a major
role in fabricating numerous functional devices with a sustainable approach.
4. Research Output
4.1.Publication
Shanmugam, K., Varanasi, S., Garnier, G., & Batchelor, W. Rapid preparation of smooth nanocellulose
films using spray coating. Cellulose, 24, no 7 (2017) 2669 -2676.
Shanmugam, Kirubanandan, Hamid Doosthosseini, Swambabu Varanasi, Gil Garnier, and Warren
Batchelor. "Flexible spray coating process for smooth nanocellulose film production." Cellulose 25, no.
3 (2018): 1725-1741.
4.2.Manuscript Communicated
Kirubanandan Shanmugam, Hamid Doosthosseini, Swambabu Varanasi, Gil Garnier, Warren
Batchelor,” Smooth nanocellulose films as air and water vapour barrier: a sustainable alternative to
polyolefin packaging”. Revised Manuscript communicated to Sustainable materials and technologies.

11. 11
4.3. Other papers not included in the main thesis.
Aysu Onur, Kirubanandan Shanmugam, Aaron Ng, Gil Garnier, Warren Batchelor, “Double layer
cellulose fibre- perlite depth filters with cellulose nanofiber top coating for microfiltration and
adsorption of positive and negatively charged contaminants”. Manuscript submitted to Journal of
Membrane Science.
4.4. Full Refereed Conference Proceedings
1. C. Czibula , C. Ganser , M. Kratzer , F. Brumbauer , M. Kräuter , K.Shanmugam , W.
Bachelor , M. Penn , M. Ebner , M. Pramstrahler , F. Pilat , T. Chien , R. Schennach , B.
Friedel and C. Teichert, “Silver Nanowires: A Versatile Tool For conductive paper” 16th
Fundamental Research Symposium "Advances in Pulp and Paper Research, Oxford
2017.Pembroke College, Oxford, UK. 3rd
– 8th
September 2017
4.5. Conference abstract
1. Kirubanandan Shanmugam, Swambabu Varanasi, Gil Garnier, Warren Batchelor, “Spray
Coating – A Rapid Method for Preparation of Free-Standing Nanocellulose Film”, International
Conference on Nanotechnology for Renewable Materials 2017, 5 – 8 June 2017 Montreal,
Quebec, Canada.
2. R. Schennach, F. Brumbauer, M. Kräuter, W. Bachelor, K.Shanmugam, C. Czibula, C. Teichert,
B. Friedel, “Nano fibrillated cellulose as a transparent electrode in an organic solar cell studied
by atomic force microscopy” European Materials Research Society, 2017 Spring Meeting, May
22 to May 26, France.
3. Kirubanandan Shanmugam, Swambabu Varanasi, Gil Garnier, Warren Batchelor, “Tuning
Nanoscale Surface Roughness and Smoothness of Nanocellulose Film via Spray Coating” ,
2017 ANFF - AMMRF Annual Research Showcase, Sydney, Australia. 22nd
-23rd
November
2017.
4. Kirubanandan Shanmugam, Hamid Doosthosseini, Swambabu Varanasi, Gil Garnier, Warren
Batchelor, “Recyclability of Spray Coated Smooth Nanocellulose films as a potentially
sustainable alternative to synthetic packaging”, International Conference on Nanotechnology
for Renewable Materials 2018, 11 – 14 June 2018 Madison, Wisconsin, United States.
5. Humayun Nadeem, Kirubanandan Shanmugam, Swambabu Varanasi, Gil Garnier, Warren
Batchelor, “Recycled nanocellulose as a sustainable material: process and barrier performance”,
International Sustainable Production and Consumption ICHEME conference, 4 – 5 the October,
Manchester, United Kingdom.
5. ANNEXURE
The thesis completed chapters are attached to this report and mentioned the progress on each
chapter in the thesis completion timeline.