The self-assembly of chitin nanocrystals into hierarchically structured functional materials
type: CreativeWork
description: To drive more sustainable technological innovations, highly abundant natural resources such as a biopolymer chitin need to be better exploited. In this work, chitin was used to produce rod-shaped nanoparticles, known as chitin nanocrystals (ChNCs) via acid hydrolysis. Firstly, hydrolysis in hydrochloric acid with varied acidity (3.0 and 5.0 M) and duration (90 to 540 min) was investigated to correlate hydrolysis conditions to colloidal and self- assembly properties of the resulting ChNCs. The post processing using tip sonication was investigated, showing that while it reduced the nanoparticle size, the self-assembly properties were not strongly affected, which contrasts with the previously reported findings for cellulose nanocrystals. Using ChNCs allowed to increase the surface charge by means of deacetylation while maintaining the nanoparticle dimensions unaffected, providing evidence that too high surface charge hinders the self-assembly. On the other hand, the process of deacetylation if applied on chitin before the acidic hydrolysis, allows to reduce the nanocrystal thickness without changing the surface charge strongly. As such, nanoparticles of higher aspect ratio can be produced. The importance of the chitin source was evaluated, revealing that ChNCs prepared from mushroom Agaricus bisporus were longer, higher aspect ratio, and less crystalline, when compared to shrimp derived ChNCs. Furthermore, fungal ChNCs exhibited self-assembly at lower nanoparticle concentrations and had smaller chiral nematic pitch in comparison to shrimp ChNC studied at comparable conditions. This broad investigation into the preparation conditions of ChNCs is the first of its kind; the field of cellulose nanocrystals is flourishing owing to comparable studies on cellulose nanocrystals. The effect of ionic strength and pH was revisited to demonstrate that these two parameters can be used to effectively tune the self-assembly of ChNCs, and in turn tune the helicoidal nanoarchitecture p…
abstract: To drive more sustainable technological innovations, highly abundant natural resources such as a biopolymer chitin need to be better exploited. In this work, chitin was used to produce rod-shaped nanoparticles, known as chitin nanocrystals (ChNCs) via acid hydrolysis. Firstly, hydrolysis in hydrochloric acid with varied acidity (3.0 and 5.0 M) and duration (90 to 540 min) was investigated to correlate hydrolysis conditions to colloidal and self- assembly properties of the resulting ChNCs. The post processing using tip sonication was investigated, showing that while it reduced the nanoparticle size, the self-assembly properties were not strongly affected, which contrasts with the previously reported findings for cellulose nanocrystals. Using ChNCs allowed to increase the surface charge by means of deacetylation while maintaining the nanoparticle dimensions unaffected, providing evidence that too high surface charge hinders the self-assembly. On the other hand, the process of deacetylation if applied on chitin before the acidic hydrolysis, allows to reduce the nanocrystal thickness without changing the surface charge strongly. As such, nanoparticles of higher aspect ratio can be produced. The importance of the chitin source was evaluated, revealing that ChNCs prepared from mushroom Agaricus bisporus were longer, higher aspect ratio, and less crystalline, when compared to shrimp derived ChNCs. Furthermore, fungal ChNCs exhibited self-assembly at lower nanoparticle concentrations and had smaller chiral nematic pitch in comparison to shrimp ChNC studied at comparable conditions. This broad investigation into the preparation conditions of ChNCs is the first of its kind; the field of cellulose nanocrystals is flourishing owing to comparable studies on cellulose nanocrystals. The effect of ionic strength and pH was revisited to demonstrate that these two parameters can be used to effectively tune the self-assembly of ChNCs, and in turn tune the helicoidal nanoarchitecture p…
author: Narkevicius, Aurimas
language: eng
keywords: chitin, nanocrystals, self-assembly, structural coloration, chiral nematic
license: https://www.repository.cam.ac.uk/bitstreams/4a0a51bb-8fe8-4d55-a2b4-3864c36c2ab6/download
license: https://creativecommons.org/licenses/by/4.0/
date published: 2021-06-18
date modified: 2026-07-22T22:23:54Z
provider: Cambridge University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Cambridge

PropertyValue
property ID: DOI
value: 10.17863/CAM.77659