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Hydrophobization of Cellulose Nanocrystals for Aqueous Colloidal Suspensions and Gels.
Nigmatullin, Rinat; Johns, Marcus A; Muñoz-García, Juan C; Gabrielli, Valeria; Schmitt, Julien; Angulo, Jesús; Khimyak, Yaroslav Z; Scott, Janet L; Edler, Karen J; Eichhorn, Stephen J.
Afiliação
  • Nigmatullin R; Department of Aerospace Engineering, Bristol Composites Institute (ACCIS), University of Bristol, Bristol BS8 1TR, United Kingdom.
  • Johns MA; Department of Aerospace Engineering, Bristol Composites Institute (ACCIS), University of Bristol, Bristol BS8 1TR, United Kingdom.
  • Muñoz-García JC; School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom.
  • Gabrielli V; School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom.
  • Schmitt J; Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom.
  • Angulo J; LSFC-Laboratoire de Synthèse et Fonctionnalisation des Céramiques UMR 3080 CNRS/Saint-Gobain CREE, Saint-Gobain Research Provence, 550 Avenue Alphonse Jauffret, Cavaillon 84300, France.
  • Khimyak YZ; School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom.
  • Scott JL; School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom.
  • Edler KJ; Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom.
  • Eichhorn SJ; Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom.
Biomacromolecules ; 21(5): 1812-1823, 2020 05 11.
Article em En | MEDLINE | ID: mdl-31984728
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.
Assuntos

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Celulose / Nanopartículas Idioma: En Ano de publicação: 2020 Tipo de documento: Article

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Celulose / Nanopartículas Idioma: En Ano de publicação: 2020 Tipo de documento: Article