10.1021/acs.biomac.9b00943.s001
Reina Tanaka
Reina
Tanaka
Yu Kashiwagi
Yu
Kashiwagi
Yuki Okada
Yuki
Okada
Tadashi Inoue
Tadashi
Inoue
Viscoelastic Relaxation of Cellulose Nanocrystals
in Fluids: Contributions of Microscopic Internal Motions to Flexibility
American Chemical Society
2019
Length distribution functions
Linear viscoelasticity
Brownian rods
Birefringence relaxation
Cellulose Nanocrystals
Microscopic Internal Motions
length distributions
birefringence relaxation
CNC
microscopy-determined histograms
relaxation modes
relaxation mechanisms
semiflexible rods well-described
Viscoelastic Relaxation
semiflexible rods
cellulose nanocrystals
flow birefringence
2019-10-28 15:37:03
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Viscoelastic_Relaxation_of_Cellulose_Nanocrystals_in_Fluids_Contributions_of_Microscopic_Internal_Motions_to_Flexibility/10060151
We
report the viscoelastic relaxation mechanisms of cellulose nanocrystals
(CNCs) dispersed individually in fluids. Linear viscoelasticity and
flow birefringence of softwood and tunicate CNC/glycerol dispersions
in the dilute regime were measured. The obtained results were then
compared with molecular theories for the linear viscoelasticity of
rigid rods and semiflexible rods at infinite dilution by taking length
distributions of CNCs into account. Although CNCs are traditionally
regarded as rigid Brownian rods, the viscoelastic relaxation was not
explained solely by the rotational motions of rods. Alternatively,
molecular theories for semiflexible rods well-described the viscoelastic
behavior; the CNCs showed additional relaxation modes derived from
microscopic internal motions including “tension” and
“curvature”, which originated from the finite flexural
rigidity. Birefringence relaxation of the CNCs was dominated by the
rotational motions of rods. Length distribution functions of the CNCs
were thus calculated from the birefringence relaxation and agreed
well with their microscopy-determined histograms.