% IMPORTANT: The following is UTF-8 encoded. This means that in the presence
% of non-ASCII characters, it will not work with BibTeX 0.99 or older.
% Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or
% “biber”.
@PHDTHESIS{Bentez:710449,
author = {Benítez, Alejandro J.},
othercontributors = {Möller, Martin and Walther, Andreas},
title = {{C}ellulose {N}anofibril {N}anopapers and {B}ioinspired
{N}anocomposites},
school = {RWTH Aachen University},
type = {Dissertation},
address = {Aachen},
reportid = {RWTH-2017-10494},
pages = {1 Online-Ressource : Illustrationen},
year = {2017},
note = {Veröffentlicht auf dem Publikationsserver der RWTH Aachen
University 2018; Dissertation, RWTH Aachen University, 2017},
abstract = {Cellulose nanofibrils (CNFs) are considered next
generation, renewable reinforcements for sustainable,
high-performance materials uniting high stiffness, strength
and toughness. They allow the formation of pure nanopapers
or can be integrated into bioinspired nanocomposites leading
to excellent multifunctional properties. The mechanical
properties endowed by nanofibrils crucially depend on
mastering structure formation processes and on understanding
interfibrillar interactions as well as deformation
mechanisms in the bulk. In this context, this thesis focus
on an in-depth understanding of the mechanical performance
of CNF nanopapers and nanocomposites. Chapter II shows how
different dispersion states of CNFs, i.e. unlike tendencies
to interfibrillar aggregation, and different relative
humidities influence the mechanical properties of the
corresponding nanopapers. The results demonstrate the
importance of controlling the state of dispersion and
aggregation of the CNFs by mediating their interactions, and
highlight the complexity associated with understanding
hierarchically structured nanofibrillar networks under
deformation. Chapter III investigates the challenges
associated with making defined CNF/polymer nanopaper hybrid
structures influenced by polymer properties in order to
deduce a quantitative picture of the deformation mechanisms.
The study discusses detailed insights on how
thermo-mechanical properties of tailor-made (co)polymers
govern the tensile properties in bioinspired CNF/polymer
settings. The derived understanding expands the ability to
tune and control the mechanical properties by rational
design criteria. Then, Chapter IV unravels in detail how
counterions, being either of the organic alkyl ammonium
series (NR4+) or of the earth metal series (Li+, Na+, Cs+),
need to be chosen to achieve outstanding combinations of
mechanical properties, extending to previously unexplored
areas. This understanding also leads to new levels of
ductility in bioinspired CNF/polymer nanocomposites at high
levels of reinforcements. Finally, the review in Chapter V
reflects my results and discusses the current state of the
art in the field of CNF nanocomposites, understanding of
mechanical performance, and derives general perspectives for
developing future CNF-based nanopapers, as well as
nanocomposites with high fractions of reinforcements
featuring rationally designed and improved property
profiles. The influence of various intercorrelated
parameters is discussed: fibril chemistry, crystallinity,
aspect ratio and degree of polymerization, colloidal
stability and film formation, as well as integration with
different counterions, polymers and nanoclays. Here, the
previous Chapters II-IV are placed as key research to
connect and dissect some of these factors by comparing with
the most comprehensive studies.},
cin = {052200 / 150000 / 154610},
ddc = {540},
cid = {$I:(DE-82)052200_20140620$ / $I:(DE-82)150000_20140620$ /
$I:(DE-82)154610_20140620$},
typ = {PUB:(DE-HGF)11},
doi = {10.18154/RWTH-2017-10494},
url = {https://publications.rwth-aachen.de/record/710449},
}
guest ::