“Nafen” alumina nanofibers as support for “Iriotec” antistatic pigments

1.

“Nafen” alumina nanofibers as support for
“Iriotec” antistatic pigments
VERSION 2.0 @ 28.12.2016

2.

Available antistatic solutions
-
discrete carbon fibers (chopped/milled)
color; difficult incorporation
-
carbon nanotubes (CNTs)
high dosage
(high percolation threshold)
-
Iriotec (Minatec) core-shell pigments
-
inorganic nanoparticles – transparent conductive oxides
(ITO/ATO++)
-
surfactants / quaternary ammonium salts (QAS)
-
conductive polymers (ICP)
-
metal salts; ionic liquids (RTIL), blends
-
other / exotic
(usually) color;
difficult incorporation
HIGH
price
non-permanent;
sensitive to
humidity
(often) insufficient
performance level
SUMMARY:
industry still seeks for GOOD
ESD solution
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3.

Concept
- Main advantage of nano-sized pigments/fillers:
reduced percolation threshold – hence, lower dosage of pigment
- Fiber morphology is also favorable
(as seen with discrete carbon fibers & CNTs)
- Colorless TCO solutions: Minatec/Iriotec & ITO/ATO nanoparticles
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4.

What is Nafen
Alumina nanofibers
produced from melt
narrow diameter
distribution
[111]
[111]
Рис.
Рис.5.8.
5.8.Ориентация
Ориентацияфасеток
фасетокувеличенного
увеличенногоразмера
размера(5(5нм
нмииболее).
более).
SAXS:
high degree of alignment
TEM:
sawtooth-shaped surface
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5.

Phase composition & temperature stability
Nafen
Nafen fibers
fibers are
are
polycrystalline
polycrystalline alumina
alumina in
in
predominantly
predominantly chi
chi phase
phase
High-Temperature XRD
At
At 1200–1400
1200–1400 C,
C,
phase
phase transformation
transformation
to
to alpha
alpha phase
phase occurs
occurs
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6.

Nafen dispersions
Pre-dispersed “Nafen“
can be used
in various liquid
(e.g. sol-gel) processes
Ultrasonic dispersion and/or
targeted surface treatment
(functionalization) allows good
(almost to single fiber) level of
dispersion
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7.

Nafen as support for functional pigments
1) nanometer size (diameter) and fiber morphology : allows to
reach low percolation threshold
2) Al2O3: high chemical/UV stability
3) relatively high SSA and “sawtooth-shaped” surface:
allows easy anchoring of active components (ITO/ATO)
4) white: no effect on color of coatings
5) surface chemistry can be tailored:
- three subtypes of Nafen available
- functionalization is possible –
e.g. to enhance adhesion to ITO coating
6) ready masterbatches for liquid medium processes (sol-gel)
can be produced
7) “bonus” reinforcement effect in polymers
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8.

Future possibilities: hybrid fillers?
CNT (ITO@Nafen)
main pigment
(“regular” Minatec)
(polymer) matrix)
concept used in thermally conductive materials:
e.g. Ai-jie Ma , Weixing Chen & Yonggang Hou (2012) Enhanced Thermal Conductivity of Epoxy
Composites with MWCNTs/AlN Hybrid Filler, Polymer-Plastics Technology and Engineering, 51:15, 1578-1582
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9.

Thank You for Attention
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