Abstract
The aim of this work was to expand the possibilities of
novel use of cellulose micro- and nanofibrils (CMNF) for
bio-based composites. The new approach in this work was
to combine inorganic pigments and CMNF in a relatively
wide range of component combinations for the generation
of -pigment-cellulose micro- and nanofibril (PCMNF)
composites. The amount of CMNF in these studies varied
between 20 and 50 wt-% in the studied composites. The
main focus of the work was on clarifying the relationship
between the raw materials used and the composite
structural properties of the final product, such as
smoothness and
porosity. The influence of manufacturing process steps on
the composite properties was studied experimentally in
both laboratory and semi-pilot scale. The composites were
manufactured by vacuum filtration in laboratory scale and
by film casting in semi-pilot scale, in both cases
followed by wet pressing, drying, and calendering. Based
on feasibility studies including techno-economic and
life-cycle assessment, new product opportunities and
markets can be captured with PCMNF composites for printed
electronics applications. There is nowadays a growing
need for the production of flexible, cost-effective, and
environmentally friendly substrates for printed
electronics applications. CMNF as a raw material has
attracted significant interest in this field. In this
work,
different functional devices were manufactured as
proof-of-concept structures to
demonstrate the usability of the developed composites for
printed electronics applications. The studied
proof-of-concepts were: 1) ink-jet printing with a
silvernanoparticle ink, 2) double-functional separator
substrate for printed
supercapacitors, 3) an ion-modulated transistor deposited
on the substrate, and 4)
screen printed antennas using silver ink and a commercial
radio frequency
identification (RFID) chip attached using a silver epoxy
resin as a functional near
field communication RFID tag on the substrate. The
developed PCMNF composites have a nanoporous pigment-CMNF
network structure that allows controlled ink absorption
properties. The required substrate porosity and
smoothness strongly depend on the used printing method,
ink, solvent, and device design. The PCMNF composites
offer a sustainable substrate for printed electronics
applications to be used at high temperatures that only
very special plastic films can currently withstand.
Original language | English |
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Qualification | Doctor Degree |
Awarding Institution |
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Supervisors/Advisors |
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Award date | 27 Oct 2017 |
Place of Publication | Espoo |
Publisher | |
Print ISBNs | 978-951-38-8571-7 |
Electronic ISBNs | 978-951-38-8570-0 |
Publication status | Published - 2017 |
MoE publication type | G4 Doctoral dissertation (monograph) |
Keywords
- cellulose nanofibrils
- cellulose microfibrils
- nanocellulose
- composite
- films
- printed electronics
- mineral pigment
- casting method
- substrate