2023-24-project-catalogue

###Enzyme-based materials for sustainable tree shelters

Project ID: 2228bd1078 (You will need this ID for your application)

Research Theme: Manufacturing The Future

UCL Lead department: Mechanical Engineering

Department Website

Lead Supervisor: Mark Miodownik

Project Summary:

Restoration of forests is part of the strategy to achieve net-zero target emissions by enhancing the removal of greenhouse gases from the atmosphere. The UK has pledged to plant 2 billion trees by 2050. The most common afforestation strategy uses tree shelters to protect planted seedlings from predation by animals such as deer, sheep and rabbits. The shelters are generally made of plastics, such as polypropylene. However, there are two environmental concerns about their deployment which have become acute now that 2 billion will be planted.

Firstly, after their useful period, tree shelters are often left at planting sites and become plastic waste that harms wildlife and pollutes the environment. Secondly, the resources used to manufacture and transport tree shelters affect the environment by producing greenhouse gases and other polluting substances [1].

Our industry partner The Woodland Trust is urgently seeking a solution to this problem. We propose to develop a biodegradable tree shelter that maintains its structural integrity until the sapling reaches maturity at which point it biodegrades rapidly and completely. Recent work has reported 3D-printable enzymatically active plastics with poly(caprolactone) (PCL) [2]. In related work polylactate (PLA) with nano-dispersed enzymes have been reported with rapid degradation profiles, again with commercial enzymes.

Previous research by the supervisory team has described chemical catalysts that can be incorporated into 3D-printed polymeric structures, where these 3D-printed constructs retained the activity of the original catalyst. This PhD project seeks to extend this work to develop a novel animate material that will biodegrade only when it receives a signal for the growing tree [3].

References

  1. Chau, C. et al (2021). Science of the Total Environment, 791. https://doi.org/10.1016/j.scitotenv.2021.148239

  2. DelRe, C. et al (2021). Nature 592, 558-563. https://doi.org/10.1038/s41586-021-03408-3

  3. Animate Materials – A prespective. Eds. Miodownik & Morris: https://royalsociety.org/topics-policy/projects/animate-materials/