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Bio-inspired Photonics

Cyan Williams

Green, environmentally friendly materials are greatly increasing in importance. Graphite and cellulose are organic natural materials; cellulose is the most abundant bio-polymer on the planet and crystalline graphite is produced by the pressure and temperature of the earth’s crust. Acid hydrolysis of cellulose isolates crystalline nanorods called cellulose nanocrystals (CNC). These rods self-assemble into a chiral nematic structure producing structural colour. Graphene can be produced via liquid phase exfoliation of graphite in water with the use of an exfoliant/dispersant. Combination of graphene and CNCs can be achieved in many different ways. CNCs can be used to exfoliate graphite and disperse graphene. Graphene can be used to produce a black background to emphasise the colour of the transparent CNC composites. Based on these promising results and compatibility, I am investigating how these two materials can enhance each other’s advantageous properties.

Industry employs expensive, silver-based or black organic inks which constricts the printed electronics market to a few applications. We are developing cheap, sustainable and vibrant inks with the potential to make almost any printed surface interactive, bringing sustainable vibrant colour to electronics. This is achieved by combining two natural materials, graphene and cellulose nanocrystals (CNCs), to create functional, sustainable and conductive water-based inks with the same striking structural colour displayed by beetles, berries and butterflies. Achievable by synergising the conductivity of graphene with the structural colour of CNCs: the absence of pigment can maintain the conducting properties of the resultant ink.



Visual Appearance of Chiral Nematic Cellulose-Based Photonic Films: Angular and Polarization Independent Color Response with a Twist.
CLC Chan, MM Bay, G Jacucci, R Vadrucci, CA Williams, GT van de Kerkhof, RM Parker, K Vynck, B Frka-Petesic, S Vignolini
– Adv Mater
Printing of Responsive Photonic Cellulose Nanocrystal Microfilm Arrays
TH Zhao, RM Parker, CA Williams, KTP Lim, B Frka-Petesic, S Vignolini
– Advanced Functional Materials
The Self-Assembly of Cellulose Nanocrystals: Hierarchical Design of Visual Appearance.
RM Parker, G Guidetti, CA Williams, T Zhao, A Narkevicius, S Vignolini, B Frka-Petesic
– Adv Mater

Graduate student

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01223 334319 (shared)

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