Application of rheology and mechanical measurements in
probing
nanocellulose–water interactions. (a,b) The influence of shear
on the dewatering of high consistency CNF furnishes: (a) Development
of the η during the measurement of 5% consistencies CNF-furnish
without cellulose fibers, subjected to the rotation rate of 200 s–1 during controlled shear rate cycle. (b) Solid content
increase Δφ, for different dewatering schemes versus shear
rates in controlled shear rate intervals 0, 40, and 200 s–1 and the flow index (K) for all furnished.307 (a,b) Adapted with permission from ref (307). Copyright 2013 Springer
Nature. (c,d) Effect of water on mechanical properties of TOCNF/PVA
films measured by DMA: (c) Storage moduli and (d) equilibrium water
contents of pure TOCNF films and TOCNF–PVA films containing
PVA at different RH levels.759 (c,d) Adapted
with permission from ref (759). Copyright 2015 Elsevier. (e–g) Using DMA to investigate
dynamic mechanical properties of stimuli responsive CNC–polymer
nanocomposites inspired by sea cucumber dermis. (e) Natural model
and bioinspired design of chemomechanical nanocomposites. Pictures
of a sea cucumber in relaxed (left) and stiffened (right) state demonstrating
the firming of dermal tissue in the vicinity of the contacted area.687 (f) Schematic representation of the architecture
and switching mechanism in the artificial nanocomposites with dynamic
mechanical properties. In the “on” state, strong hydrogen
bonds between rigid, percolating CNCs maximize stress transfer and
therewith the overall modulus of the nanocomposite. The interactions
are switched “off” by the introduction of a chemical
regulator that allows for competitive hydrogen bonding.687 (g) Time-dependent modulus decrease of neat
poly(vinyl acetate) (PVAc) and a 12.2% v/v PVAc/CNC nanocomposite
upon immersion into artificial cerebrospinal fluid and increasing
the temperature from 23 to 37 °C.687 (e–g) Adapted with permission from ref (687). Copyright 2008 The American
Association for the Advancement of Science.