TY - JOUR
T1 - Edge-On (Cellulose II) and Face-On (Cellulose I) Adsorption of Cellulose Nanocrystals at the Oil-Water Interface
T2 - A Combined Entropic and Enthalpic Process
AU - Haouache, Somia
AU - Chen, Yu
AU - Jimenez-Saelices, Clara
AU - Cousin, Fabrice
AU - Chen, Pan
AU - Nishiyama, Yoshiharu
AU - Jerome, François
AU - Capron, Isabelle
N1 - Publisher Copyright:
© 2022 The Authors. Published by American Chemical Society.
PY - 2022/9/12
Y1 - 2022/9/12
N2 - Nanocelluloses can be used to stabilize oil-water surfaces, forming so-called Pickering emulsions. In this work, we compare the organization of native and mercerized cellulose nanocrystals (CNC-I and CNC-II) adsorbed on the surface of hexadecane droplets dispersed in water at different CNC concentrations. Both types of CNCs have an elongated particle morphology and form a layer strongly adsorbed at the interface. However, while the layer thickness formed with CNC-I is independent of the concentration at 7 nm, CNC-II forms a layer ranging from 9 to 14 nm thick with increasing concentration, as determined using small-angle neutron scattering with contrast-matched experiments. Molecular dynamics (MD) simulations showed a preferred interacting crystallographic plane for both crystalline allomorphs that exposes the CH groups (100 and 010) and is therefore considered hydrophobic. Furthermore, this study suggests that whatever the allomorph, the migration of CNCs to the oil-water interface is spontaneous and irreversible and is driven by both enthalpic and entropic processes.
AB - Nanocelluloses can be used to stabilize oil-water surfaces, forming so-called Pickering emulsions. In this work, we compare the organization of native and mercerized cellulose nanocrystals (CNC-I and CNC-II) adsorbed on the surface of hexadecane droplets dispersed in water at different CNC concentrations. Both types of CNCs have an elongated particle morphology and form a layer strongly adsorbed at the interface. However, while the layer thickness formed with CNC-I is independent of the concentration at 7 nm, CNC-II forms a layer ranging from 9 to 14 nm thick with increasing concentration, as determined using small-angle neutron scattering with contrast-matched experiments. Molecular dynamics (MD) simulations showed a preferred interacting crystallographic plane for both crystalline allomorphs that exposes the CH groups (100 and 010) and is therefore considered hydrophobic. Furthermore, this study suggests that whatever the allomorph, the migration of CNCs to the oil-water interface is spontaneous and irreversible and is driven by both enthalpic and entropic processes.
UR - http://www.scopus.com/inward/record.url?scp=85138116040&partnerID=8YFLogxK
U2 - 10.1021/acs.biomac.2c00201
DO - 10.1021/acs.biomac.2c00201
M3 - Article
C2 - 36044601
AN - SCOPUS:85138116040
SN - 1525-7797
VL - 23
SP - 3517
EP - 3524
JO - Biomacromolecules
JF - Biomacromolecules
IS - 9
ER -