Bio-mimetic Architectures with Sustainable Polymers

Lead Research Organisation: University of Cambridge
Department Name: Chemistry


The aim of the project is to develop a detailed understanding of how biopolymer-based nanoparticles such as cellulose and chitin nanocrystals (CNC and ChNC) interact with polymeric matrices. A rigorous characterisation of the properties of the building blocks, in terms of size (distribution), crystallinity and surface charge will enable us to develop standardised techniques for the reliable and robust use of these materials in composite systems. This project builds on the expertise within the group and will aim to develop control over the self-assembly properties of CNC and ChNC and directly apply them in the preparation of composite materials from guar and other cellulose derivatives. The student will identify the properties of CNC and ChNC that determines their dispersion in polymer matrices yielding composites, and determine how surface charge and morphology of the nanocrystalline materials obtained from different natural sources (and/or extracted with different procedures) affect the final properties of the composites. Moreover, we aim to develop a batch-independent isolation protocol that will enable optimised composite performance. In particular, we will focus our attention on other polysaccharides including guar and hydroxypropyl cellulose.

Studentship Projects

Project Reference Relationship Related To Start End Student Name
EP/N509620/1 30/09/2016 29/09/2022
1800758 Studentship EP/N509620/1 30/09/2016 29/09/2020 Aurimas Narkevicius
Description Bio-polymer named chitin, which is highly considered to be a waste product in food industry, was extracted from shrimp shells or mushroom. It was then converted into rod-like particles with dimensions at a nanoscale. These dimensions as well as other parameters were found to be tuneable by altering the preparation methodology. The chitin nanoparticles can be easily dispersed in water under slight acidic condition and remain stable for months. When the nanoparticle concentration increases, chitin nanocrystals exhibited liquid crystalline behaviour by self-assembling to a complex hierarchical structure, called chiral nematic, which can be visualised as a circular staircase. The twisting behaviour of this architecture proved to depend on various parameters like concentration of salt or pH and thus could be predictably controlled. It was observed that by simply drying the nanoparticles suspended in water, transparent films can be made with the above-mentioned hierarchical structure preserved and resembling the structures found in nature e.g. crab shells or scarabeid beetles. The retained structure could be well controlled and even allowed to achieve unprecedented structures of chitin which could give rise to the structural coloration, meaning that the structure would have colour without the need of additional dyes or pigments. These chitin structures are biodegradable and highly biocompatible yet have interesting functionalities and thus could found useful as colorants in the future. Recently we have discovered that structural coloration, such as in the scarabeid beetles, may be produced using chitin nanocrystal self-organisation. We are finalising our results in order to submit a report on it to a peer reviewed journal.
Exploitation Route Chitin is an abundant biomaterial, however, it is still considered to be a huge waste especially in the food industry as crustacean shells are disposed. This research shows ways in which chitin could be utilised smartly to develop functional hierarchical materials which resemble those found in nature e.g. tough crab shells and coloured scarabaeid beetles. We present the ways in which both of these properties can be realised, however, the processes need to be further investigated and optimised in academic and industrial (e.g. food, cosmetics) setting.
To realise these fascinating materials, this works investigated in detail the liquid crystalline properties of chitin nanocrystals which exemplifies a colloidal liquid crystalline system. Since the detailed understanding of such systems is not fully achieved, studied chitin nanocrystals could provide an alternative system to investigate some fundamental questions such as the origin of chirality in the self-assemblying colloidal liquid crystals.

It can also serve very well as a topic for outreach and public communication as this work relates components which are familiar to all: shrimp, crab, beetles shells and mushroom, with the science in utilising them for development of optically or mechanically interesting materials.

The recent findings in the use of chitin nanocrystals as means to produce structurally coloured materials reveals that it may be used by others (scientists, artists, food industry and cosmetics) in the use of coloured material which is biodegradable and biocompatible.
Sectors Agriculture, Food and Drink,Chemicals,Environment,Manufacturing, including Industrial Biotechology,Pharmaceuticals and Medical Biotechnology

Description The findings have been presented in the outreach events e.g. annual University of Cambridge Science festival, Chemistry Department. I present the research that my group does by introducing eye catching various beetles which have interesting hierarchical architectures. They are thereafter linked directly with the work that I am doing as I work on producing analogous structures in laboratory by means of self-assembly of chitin nanocrystals using chitin, a biodegradable material sourced from nature and which can be done in a renewable fashion.
First Year Of Impact 2019
Sector Education,Environment
Impact Types Societal

Title Research data supporting "Controlling the self-assembly behavior of aqueous chitin nanocrystal suspensions" 
Description Supporting data for the article titled "Controlling the self-assembly behavior of aqueous chitin nanocrystal suspensions". The article was accepted for publication in 2019 in the journal "Biomacromolecules". Electronic supporting information is available from the publisher (ACS Publications). The data is provided with a structured set of folders compressed in zip, each related to different characterisation methods used. The individual tick of the scale bar images corresponds to a spacing of 10 µm. See the Readme file for more information. 
Type Of Material Database/Collection of data 
Year Produced 2019 
Provided To Others? Yes