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oai:recercat.cat:2117/3405012026-02-07T10:54:03Zcom_2072_1033col_2072_452950

Patience is a virtue: self-assembly and physico-chemical properties of cellulose nanocrystal allomorphs Delepierre, Gwendoline Eyley, Samuel Thielemans, Wim Weder, Christoph Cranston, Emily Zoppe, Justin Orazio Universitat Politècnica de Catalunya. Departament de Ciència i Enginyeria de Materials Àrees temàtiques de la UPC::Matemàtiques i estadística Cellulose nanocrystals Cel·lulosa Nanocristalls Cellulose nanocrystals (CNCs) are bio-based rod-like nanoparticles with a quickly expanding market. Despite the fact that a variety of production routes and starting cellulose sources are employed, all industrially produced CNCs consist of cellulose I (CNC-I), the native crystalline allomorph of cellulose. Here a comparative study of the physico-chemical properties and liquid crystalline behavior of CNCs produced from cellulose II (CNC-II) and typical CNC-I is reported. CNC-I and CNC-II are isolated by sulfuric acid hydrolysis of cotton and mercerized cotton, respectively. The two allomorphs display similar surface charge densities and ¿-potentials and both have a right-handed twist, but CNC-II have a slightly smaller average length and aspect ratio, and are less hygroscopic. Interestingly, the self-assembly behavior of CNC-I and CNC-II in water is different. Whilst CNC-I forms a chiral nematic phase, CNC-II initially phase separates into an upper isotropic and a lower nematic liquid crystalline phase, before a slow reorganization into a large-pitch chiral nematic texture occurs. This is potentially caused by a combination of factors, including the inferred faster rotational diffusion of CNC-II and the different crystal structures of CNC-I and CNC-II, which are responsible for the presence and absence of a giant dipole moment, respectively. Peer Reviewed Postprint (published version) 2020 Article Delepierre, G. [et al.]. Patience is a virtue: self-assembly and physico-chemical properties of cellulose nanocrystal allomorphs. "Nanoscale", 2020, vol. 12, núm. 33, p. 17480-17493. 2040-3364 https://hdl.handle.net/2117/340501 10.1039/D0NR04491A eng https://pubs.rsc.org/en/content/articlelanding/2020/NR/D0NR04491A#!divAbstract http://creativecommons.org/licenses/by-nc-nd/3.0/es/ Restricted access - publisher's policy Attribution-NonCommercial-NoDerivs 3.0 Spain 14 p. application/pdf application/pdf