Cellulose Nanocrystal Aqueous Colloidal Suspensions Evidence of Density Inversion at the Isotropic-Liquid Crystal Phase Transition

Cellulose Nanocrystal Aqueous Colloidal Suspensions : Evidence of Density Inversion at the Isotropic-Liquid Crystal Phase Transition

© 2022 The Authors. Advanced Materials published by Wiley-VCH GmbH.

Bibliographische Detailangaben
Veröffentlicht in:Advanced materials (Deerfield Beach, Fla.). - 1998. - 34(2022), 28 vom: 03. Juli, Seite e2108227
1. Verfasser: da Rosa, Rafaela R (VerfasserIn)
Weitere Verfasser: Silva, Pedro E S, Saraiva, Diogo V, Kumar, Anant, de Sousa, António P Mendes, Sebastião, Pedro, Fernandes, Susete N, Godinho, Maria Helena
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2022
Zugriff auf das übergeordnete Werk:Advanced materials (Deerfield Beach, Fla.)
Schlagworte:Journal Article aqueous suspensions cellulose nanocrystals (CNCs) liquid crystals low-density liquid crystalline phase
Beschreibung
Zusammenfassung:© 2022 The Authors. Advanced Materials published by Wiley-VCH GmbH.
The colloidal suspensions of aqueous cellulose nanocrystals (CNCs) are known to form liquid crystalline (LC) systems above certain critical concentrations. From an isotropic phase, tactoid formation, growth, and sedimentation have been determined as the genesis of a high-density cholesteric phase, which, after drying, originates solid iridescent films. Herein, the coexistence of a liquid crystal upper phase and an isotropic bottom phase in CNC aqueous suspensions at the isotropic-nematic phase separation is reported. Furthermore, isotropic spindle-like domains are observed in the low-density LC phase and high-density LC phases are also prepared. The CNCs isolated from the low- and high-density LC phases are found to have similar average lengths, diameters, and surface charges. The existence of an LC low-density phase is explained by the presence of air dissolved in the water present within the CNCs. The air dissolves out when the water solidifies into ice and remains within the CNCs. The self-adjustment of the cellulose chain conformation enables the entrapment of air within the CNCs and CNC buoyancy in aqueous suspensions
Beschreibung:Date Revised 14.07.2022
published: Print-Electronic
Citation Status PubMed-not-MEDLINE
ISSN:1521-4095
DOI:10.1002/adma.202108227