Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

Hydrophobization of Cellulose Nanocrystals for Aqueous Colloidal Suspensions and Gels

Nigmatullin, Rinat ; Johns, Marcus A. ; Muñoz-García, Juan C. ; Gabrielli, Valeria ; Schmitt, Julien LU ; Angulo, Jesús ; Khimyak, Yaroslav Z. ; Scott, Janet L. ; Edler, Karen J. LU orcid and Eichhorn, Stephen J. (2020) In Biomacromolecules 21(5). p.1812-1823
Abstract

Surface hydrophobization of cellulose nanomaterials has been used in the development of nanofiller-reinforced polymer composites and formulations based on Pickering emulsions. Despite the well-known effect of hydrophobic domains on self-assembly or association of water-soluble polymer amphiphiles, very few studies have addressed the behavior of hydrophobized cellulose nanomaterials in aqueous media. In this study, we investigate the properties of hydrophobized cellulose nanocrystals (CNCs) and their self-assembly and amphiphilic properties in suspensions and gels. CNCs of different hydrophobicity were synthesized from sulfated CNCs by coupling primary alkylamines of different alkyl chain lengths (6, 8, and 12 carbon atoms). The... (More)

Surface hydrophobization of cellulose nanomaterials has been used in the development of nanofiller-reinforced polymer composites and formulations based on Pickering emulsions. Despite the well-known effect of hydrophobic domains on self-assembly or association of water-soluble polymer amphiphiles, very few studies have addressed the behavior of hydrophobized cellulose nanomaterials in aqueous media. In this study, we investigate the properties of hydrophobized cellulose nanocrystals (CNCs) and their self-assembly and amphiphilic properties in suspensions and gels. CNCs of different hydrophobicity were synthesized from sulfated CNCs by coupling primary alkylamines of different alkyl chain lengths (6, 8, and 12 carbon atoms). The synthetic route permitted the retention of surface charge, ensuring good colloidal stability of hydrophobized CNCs in aqueous suspensions. We compare surface properties (surface charge, ζ potential), hydrophobicity (water contact angle, microenvironment probing using pyrene fluorescence emission), and surface activity (tensiometry) of different hydrophobized CNCs and hydrophilic CNCs. Association of hydrophobized CNCs driven by hydrophobic effects is confirmed by X-ray scattering (SAXS) and autofluorescent spectroscopy experiments. As a result of CNC association, CNC suspensions/gels can be produced with a wide range of rheological properties depending on the hydrophobic/hydrophilic balance. In particular, sol-gel transitions for hydrophobized CNCs occur at lower concentrations than hydrophilic CNCs, and more robust gels are formed by hydrophobized CNCs. Our work illustrates that amphiphilic CNCs can complement associative polymers as modifiers of rheological properties of water-based systems.

(Less)
Please use this url to cite or link to this publication:
author
; ; ; ; ; ; ; ; and
publishing date
type
Contribution to journal
publication status
published
in
Biomacromolecules
volume
21
issue
5
pages
12 pages
publisher
The American Chemical Society (ACS)
external identifiers
  • scopus:85084721483
  • pmid:31984728
ISSN
1525-7797
DOI
10.1021/acs.biomac.9b01721
language
English
LU publication?
no
additional info
Publisher Copyright: © 2020 American Chemical Society.
id
a893eb7e-8429-4283-b4f4-9b4f86184f7d
date added to LUP
2023-01-18 09:00:34
date last changed
2025-06-15 13:55:04
@article{a893eb7e-8429-4283-b4f4-9b4f86184f7d,
  abstract     = {{<p>Surface hydrophobization of cellulose nanomaterials has been used in the development of nanofiller-reinforced polymer composites and formulations based on Pickering emulsions. Despite the well-known effect of hydrophobic domains on self-assembly or association of water-soluble polymer amphiphiles, very few studies have addressed the behavior of hydrophobized cellulose nanomaterials in aqueous media. In this study, we investigate the properties of hydrophobized cellulose nanocrystals (CNCs) and their self-assembly and amphiphilic properties in suspensions and gels. CNCs of different hydrophobicity were synthesized from sulfated CNCs by coupling primary alkylamines of different alkyl chain lengths (6, 8, and 12 carbon atoms). The synthetic route permitted the retention of surface charge, ensuring good colloidal stability of hydrophobized CNCs in aqueous suspensions. We compare surface properties (surface charge, ζ potential), hydrophobicity (water contact angle, microenvironment probing using pyrene fluorescence emission), and surface activity (tensiometry) of different hydrophobized CNCs and hydrophilic CNCs. Association of hydrophobized CNCs driven by hydrophobic effects is confirmed by X-ray scattering (SAXS) and autofluorescent spectroscopy experiments. As a result of CNC association, CNC suspensions/gels can be produced with a wide range of rheological properties depending on the hydrophobic/hydrophilic balance. In particular, sol-gel transitions for hydrophobized CNCs occur at lower concentrations than hydrophilic CNCs, and more robust gels are formed by hydrophobized CNCs. Our work illustrates that amphiphilic CNCs can complement associative polymers as modifiers of rheological properties of water-based systems.</p>}},
  author       = {{Nigmatullin, Rinat and Johns, Marcus A. and Muñoz-García, Juan C. and Gabrielli, Valeria and Schmitt, Julien and Angulo, Jesús and Khimyak, Yaroslav Z. and Scott, Janet L. and Edler, Karen J. and Eichhorn, Stephen J.}},
  issn         = {{1525-7797}},
  language     = {{eng}},
  month        = {{05}},
  number       = {{5}},
  pages        = {{1812--1823}},
  publisher    = {{The American Chemical Society (ACS)}},
  series       = {{Biomacromolecules}},
  title        = {{Hydrophobization of Cellulose Nanocrystals for Aqueous Colloidal Suspensions and Gels}},
  url          = {{http://dx.doi.org/10.1021/acs.biomac.9b01721}},
  doi          = {{10.1021/acs.biomac.9b01721}},
  volume       = {{21}},
  year         = {{2020}},
}