1. No category

Nanotechnologies Potential
in Forest and Paper Industry
Nano-Hemicelluloses
Nano
Hemicelluloses For
Barrier/Strength
g Improvements
p
Improvements in Tensile Index with 4%
Applie d Glucuroxylan
Tensilee Index
60
50
40
30
20
SW ECF
P l
Pulp
Bulk
E i h
Enrich
Xylan
Surface
E i h d
Enriched
Xylan
Very recent developments in nano-lignin suggest new barrier opportunities
Nano-Enhanced Paper: Coatings
C
Current
S
Studies
di
n
n
NH3+ Cl-
N Cl+
Nanosized TiO2 materials enhance titania’s
unique
i
properties
ti by
b giving
i i large
l
surface
f
areas
Tube
Hollow ball
Hollow ball
Belt
Film
Super hydrophobic Barrier Coating
Super-hydrophobic
Method
M
th d off enhancing
h
i hydrophibicity:
h d hibi it Lowering
L
i surface
f
energy by coating of hydrophobic material.
However the material with the lowest surface
However,
energy (6.7 mJ/m2 for a surface with regularly
aligned closest-hexagonal-packed –CF3 groups)
gives
i
a water
t contact
t t angle
l off only
l around
d 120o.
Super hydrophobic surface: Both receding
Super-hydrophobic
advanced water contact angles above 150o.
and
Water,
W
t
i
ice,
grease, and
d bio
bi contaminants
t i
t will
ill nott be
b
able to deposit on super-hydrophobic surfaces
Lotus Effect
(a)
(b)
(c)
Figure 1. (a) SEM images of the lotus leaf surface.
Schematic representation of the self-cleaning
mechanism: moving of water droplet along
contaminated smooth (b) and rough (c) surfaces.
http://www.biologie.uni-hamburg.de
Coatings with hydrophobic silica (colloidal silica + FAS-17)
Figure 4. SEM images of films on glass and the shapes of water droplets on the
films. (a) glass + heptadecafluorodecyltrimethoxysilan (FAS-17) coating; (b) film
from methanol based colloidal silica and (c) film from methyl ethyl ketone (MEK)
based silica.
T. Watanabe, et al, “Processing of roughened silica film by coagulated colloidal silica for super-dydrophobic coatng”
J Materials Sci Lett 2001, 20, 1975.
Barrier Coating with Nanomaterials
• PolymerPolymer
P
l
-clay
l nanohybrids
h b id are important
i
new materials
i l
– Improve modules, scratch properties, strength, stiffness,
heat resistance and preservation
preservation, etc.
etc
– Increase barrier properties for gas, water and grease
– Can
C be
b usedd for
f textile,
t til painting,
i ti coating,
ti andd many others
th
• Barrier properties are very important for some paper products,
such as containers for milk,
milk juice,
juice ice cream,
cream meet,
meet fish,
fish fruit,
fruit
microwave fast food, food plates and boxes, drink cups, photo
papers,
p
p , etc
• Problems of waxed food containers: unun-recyclable, cannot be
used as containers for milk, juice, ice cream, fast food, food
plates
Nano-Optical
p
Effects
New Value Added Features: Opticals
ƒ
Objective: Develop new fiber-based products that take advantage of the
special optical and photonic properties of nanomaterials and that enable
manufacturers to:
o Increase opacity and light barrier properties of paper and paperboard
o Utilize new methods for holographic imagery and graphics on paper
surfaces
o Employ novel optical effects on paper surfaces and in paper webs
Abalone
Shell
Source: Belcher et al 1999
ƒ Target market opportunities:
o Lightweight printing papers with high opacity
o Paperboard with high light barrier for packaging light-sensitive contents
without use of metal foil
o Papers and folding cartons with new security and anti-counterfeiting
features
o White
White-surfaced
surfaced paper and paperboard with high content of recycled and/or
unbleached fiber
ƒ Enabling technologies – pre-competitive research:
o Photonic effects of nanomaterials for light scattering, light absorption, light
transmission wavelength shifting
transmission,
shifting, etc.
etc
o Imaging and holography with nanoparticles
o Nanomaterials that react to ambient stimuli optically, electronically, or
mechanically
Processes for preparing commercial quantities of photonic nanomaterials and for
applying ultra-thin coatings onto paper surfaces
Nanostructured Filler Engineering: Mg(OH)2
Nanobelts synthesized by Y. Deng
Low cost
Low density (2.4)
High brightness
No retention aid is needed (good formation)
L iimpactt on paper strengths
Less
t
th
Nano-Filler
Nano
Filler Properties
Nanostructured Filler Engineering
Nanosilicate Fibril Fillers
Vijay Mathur, 2004 TAPPI Paper Summit, May 3-5, 2004, Atlanta, GA, USA
Nanostructured Filler Engineering
Clay
Charge
Charge
Polymer
Polymer
Polymer
Control
Coated clay
36
34
- Layer-by-layer coating on clay fillers
- Tailor fill surface properties
- Enhances tensile and other physical
properties
-
32
Tensiile Index
Charge
30
28
26
5%
10%
15%
Percentage clay
20%
9 layer
Nano-Enhanced Paper: Surface
Fibrilation
SEM of Fiber
Nano-Enhanced Paper:
p
ZDT Strength Improvement
100
90
80
ZDT (PS
SI)
70
60
50
40
30
20
10
0
Control
Nano fibril
33% increase in ZDT
Nano-Enhanced Paper:
p
Folding Strength Improvement
2
Folding In
ndex (times**cm /g)
4
3.5
3
2.5
2
15
1.5
1
0.5
0
Control
Nano fibril
3.5 time increases in the folding strength
Polymer
Polymery
-Nanoclayy Composites
p
Th thickness
The
thi k
off
nanoclay in the
composite is about
1nm.
B i coating
Barrier
ti for
f
food containers and
paper packages
Water and vapor
resistance, fatty and
oil resistance,, board
strength
Key Issues Using PolymerNanoclay for Barrier Coating
• Water Based
– Emulsion/miniemulsion polymerization
• Uniformed Distribution (no aggregates in the
polymer matrix)
– Correctly using surfactant
• Strong affinity between polymer and nanoclay
– Seeding and modification technology
H2O
H2O
Functional PaperPaper-Packaging
• Nano
N
particles
i l embedded
b dd d in
i cellulosic
ll l i
fibers can pprovide:
– Unique antianti-bacterial fungal properties
– Timed
Ti d release
l
– Environmentally
y responsive
p
signals
g
Advanced Bio-Based Materials
mm
Research Opportunities
100 μm
1μ
μm
10 nm
10 μm
nm
Nanocellulose
1 cm
H+/Enzyme/
M h i l
Mechanical
AFM of Cellulose
Nanowiskers
OAc
HO
O
O
O
OH
AcO
O
HO
O
Birefringence of
Cellulose Nanowiskers
OH
O-Xylan
O
Crosslinked
Xylan Films
W t Vapour
Water
V
Transmission/h
T
i i /h
400
300
200
100
0
0%
Green Package
5
% Sulfonated Whiskers
10
O2 &
strength
TEM of Cellulose Nanowiskers1
• Nano in Pulp and Paper
–
–
–
–
–
–
–
–
–
–
–
Nanofiller Engineering
Superhydrophobic – Superhydrophilic Fibers
Barrier coatings and Films
Nanostructured Papermaking Additives
Optical Properties
Improved Printing
Higher Bulk
Porous Structures
Foams
Composites
Intelligent
lli
Paper