Newswise — Mycelium, an astounding web of fungal fibers that can flourish in organic refuse and dimness, might serve as a foundation for eco-friendly flame-resistance. RMIT scientists are manipulating its structure chemically to utilize its fire-inhibiting characteristics.

Associate Professor Tien Huynh, a specialist in biotechnology and mycology, affirmed that they have demonstrated the ability to cultivate mycelium from sustainable organic waste.

"Huynh, from the School of Science, stated, 'Typically, fungi are discovered in a composite form blended with residual feed material. However, we have discovered a method to cultivate pure mycelium sheets that can be layered and engineered for various applications. These range from flat panels intended for the construction sector to a material resembling leather for the fashion industry.'"

The innovative technique of producing paper-thin mycelium sheets, akin to wallpaper, is achieved without pulverizing the filamentous network of the mycelium. Rather, researchers employed alternative growth conditions and chemicals to create the thin, consistent, and crucially fire-resistant material.

Fungi fireproofing our buildings

The researchers are primarily dedicated to developing bio-derived, fire-retardant cladding for buildings, with a specific focus on preventing tragedies similar to the Grenfell Tower fire. In that incident, the highly flammable cladding component contributed to the rapid spread of the deadly blaze.

Associate Professor Everson Kandare, a specialist in the flammability and thermal properties of biomaterials and co-author of the study, emphasized the significant potential of mycelium as a fireproofing material.

Kandare highlighted that mycelium possesses a notable advantage in its ability to generate a thermal protective char layer when subjected to fire or radiant heat. The endurance of mycelium char at higher temperatures and for longer durations enhances its efficacy as a fireproof material.

In addition to its effectiveness, Kandare explained that mycelium-based cladding can be manufactured from renewable organic waste. Furthermore, when burned, it does not pose harm to the environment. This makes it an environmentally-friendly option for fireproofing applications.

Where composite cladding panels are used, they usually contain plastics – which produce toxic fumes and heavy smoke when they burn.

Kandare noted that while fire retardants containing bromide, iodide, phosphorus, and nitrogen may be effective, they also come with detrimental health and environmental consequences. These substances, which can act as carcinogens and neurotoxins, have the potential to escape and persist in the environment, causing harm to both plant and animal life.

“Bioderived mycelium produces naturally occurring water and carbon dioxide.”

Bringing the research to life

This research could eventually lead to improved and eco-friendly cladding for buildings.

“Plastics are quick and easy to produce, whereas fungi is slow to grow and relatively harder to produce at scale,” said Huynh.

Kandare mentioned that they have received interest from the mushroom industry regarding the utilization of their waste products infused with fungi. By collaborating with the mushroom industry, it would eliminate the necessity for new farms while generating fire-safe products in an environmentally sustainable manner. This collaborative approach holds promise for meeting fire safety requirements while reducing environmental impact.

The researchers are currently exploring the development of fungal mats that are reinforced with engineered fibers. This approach aims to prolong ignition, decrease the intensity of flames, and enhance the fire safety ranking of the materials. By combining fungal mats with engineered fibers, they seek to further enhance the fire-resistant properties and overall safety of the products.

The research paper titled "Fireproofing flammable composites using mycelium: Investigating the effect of deacetylation on the thermal stability and fire reaction properties of mycelium" is authored by Nattanan Chulikavit and published in the journal Polymer Degradation and Stability. The paper delves into the examination of how deacetylation impacts the thermal stability and fire reaction properties of mycelium, with the aim of enhancing fireproofing capabilities in flammable composites. The paper's DOI is https://doi.org/10.1016/j.polymdegradstab.2023.110419.

It builds on preliminary research published by the experts in high-ranked international journals, Polymer Degradation and Stability and Nature’s Scientific Reports.

This project is a major collaboration involving RMIT University, the University of New South Wales, the Hong Kong Polytechnic University and the Australian Research Council Training Centre in Fire Retardant Materials and Safety Technologies.

Journal Link: Polymer Degradation and Stability