Sustainable materials from waste

Our research begins with materials that have been discarded — PET bottles, waste textiles, crab and shrimp shells, end-of-life electronics — and asks what is required to convert each of them into a material with useful function: adsorbents for toxic metals and organic pollutants, porous frameworks for CO2 capture, polymer networks for ground reinforcement.

Their abundance and low cost are what make such feedstocks attractive; their heterogeneity and contamination are what make them difficult. Reconciling the two requires methods drawn from chemistry, materials science and environmental engineering, and that is where most of our work is directed.

Waste streams used as feedstocks: shrimp shells, e-waste, sawdust, textiles, plastics and circuit boards, around a recycling symbol
Materials from plastic waste
Waste PET fabric metallized with catalytic gold nanoparticles, visible as brown areas

Image: waste PET fabric metallized with catalytic gold nanoparticles (brown areas)

Conventional mechanical recycling returns plastic to a lower grade with each cycle. We work instead on chemical routes that decompose PET into defined intermediates and rebuild them into materials of higher value — metal-organic frameworks for CO2 capture, hydrogels and magnetic particles for the adsorption of toxic metals and dyes, and fibres functionalised with catalytic nanoparticles. The viability of each conversion route is considered alongside the properties of the product.

Materials from marine waste
Shrimp shell waste, which contains 30-40% chitin

Image: shrimp shell waste containing 30-40% of chitin

Shrimp and crab shells are discarded in large quantities and contain 30–40% chitin. Deacetylation yields chitosan, one of the few biomass-derived polymers with a cationic character, which allows it to bind anionic pollutants directly and to form stable complexes with anionic polymers and colloids. We exploit this to construct hydrogels, beads and composite adsorbents for the removal of heavy metals, dyes, pharmaceuticals and radioactive caesium from water.

  • Removal of heavy metals, dyes, and other environmental pollutants using chitosan-based adsorbents such as chitosan magnetic beads (Chem. Eng. J. 2018), hydrogels of chitosan with DNA (Gels 2021) and biomass nanofibers (Gels 2024).
  • Removal of Cs+ ions as an approach for treatment of radioactive Cs+ pollution (J. Hazard. Mater. 2019)
Char adsorbents from waste
Mixed char of chitosan and PET

Image: mixed char of chitosan and PET

Pyrolysis and hydrothermal treatment convert both biomass and plastic waste into porous carbons suitable for the adsorption of pollutants from water and soil. We examine these feedstocks separately and in combination, since co-processing can yield materials that outperform either precursor alone — the addition of PET to crab shell waste, for example, improves heavy-metal uptake. Under milder and more controlled conditions the same chemistry produces fluorescent carbon nanomaterials, which we apply to sensing rather than adsorption.

Soil improvement by biomass polymers
SEM image of biopolymer films in reinforced soil

Image: SEM images of biopolymer films in reinforced soil

Ground improvement conventionally relies on cement, with a substantial associated carbon burden. We are examining whether polymers obtained from biomass waste can perform part of the same function: chitosan and carboxymethyl cellulose, combined as oppositely charged pairs, form networks throughout soil, sand and clay that increase mechanical strength. The same networks retain heavy-metal ions, so a single treatment can serve both for reinforcement and for containment of contamination. The work is conducted jointly with the Geotechnical Laboratory and has progressed from laboratory tests to field trials.

Recovery of critical elements from waste
A printed circuit board from electronic waste

Image: PCB (printed circuit board)

Electronic waste contains gold and other precious metals at concentrations far exceeding those of natural ores. The difficulty lies in recovering them selectively, without recourse to the aggressive reagents conventionally employed. We address both stages of the process: organic solvents that extract gold from leachates with useful selectivity, and adsorbents prepared from waste PET that recover dissolved metals from solution. Photovoltaic panels represent a further waste stream of growing importance.

  • Extraction of gold from e-waste by organic solvents (Sep. Purif. Technol. 2026)
  • Recovery of valuable metals from e-waste leachates using metal adsorbents derived from PET waste
Collaboration

Much of our work develops through collaboration. We are open to joint projects, sample exchange, and visiting researchers.

We are looking for industrial partners for scale-up. Several of our waste-conversion technologies are established at laboratory scale — including the direct synthesis of CO2-capture materials from waste PET bottles, some of them under Japanese patent application — and we are interested in working with companies to take them further.

We are also looking for partners with expertise in life cycle assessment to evaluate the environmental performance of the technologies we develop.

Current collaborations:

Contact us