PhD-position | Robust structural colour coatings of wood based on self-assembled cellulose nanocrystal CNC

Project description:

The aim of the project is to identify and verify suitable strategies to strongly bond structural colors formed out of CNCs to the wood substrate and to overcome the disadvantage of the current absence of water resistance. Design principles and approaches found in nature may act as a starting point. As possible approaches we see enzymatic modification of the wood surface to enhance interaction, physical methods to induce energy (heat, rays), green chemical approaches to improve the cohesion of the cellulose assembly or incorporation of fully biobased matrix polymers or waxes.

Background:

Formation of vivid colours is already nicely possible with Cellulose Nanocrystals. For the mechanism of colour adjustment several strategies are established, while the understanding of interaction of wood and its role in colour formation is in the early stage. As main barrier moisture stability is close to zero, as a single drop of water is able to destroy or remove the structure, as the interaction of CNC is based on weak secondary bonds only.

Based on biomimetic approaches, green chemistry or biotechnological methods CNC shall be connected to the wood structure and interconnected with each other.

Research Objectives:

- As an outcome an ideally purely lignocellulose based structural colour should be able to coat the lignocellulosic material wood and thus enable realizing a single material concept.

- Identifying and analyzing possible modification approaches addressing the interaction within the CNC structure, as well as between wood and the structure

- Verify and develop selected strategies

Methods:

Color formation by CNC self-assembly. Biotechnological, chemical or physical methods to be identified depending on approaches selected. Analyses of structural color assemblies by various microscopic techniques on suitable length scales (light microscopy, atomic force microscopy, scanning electron microscopy) including ultramicrotomy as sample preparation. Color determination, surface resistance in dry state and towards water, nanoindentation, …

Where to apply:

https://www.circularbioengineering.at/