A recently published study shows promising results from combining edible turkey tail fungus with a solution of wood fibers. The end product is a natural sustainable waterproof coating that may be be a replacement for single-use plastic food wrap and synthetic paper cup coatings.
University of Maine researchers wanted to develop an environmentally safe coating that would resist water, oil and grease but was also was food-safe, so they experimented with the mycelium from the turkey tail mushroom (Trametes versicolor).
The mycelium is a root-like structure found in the wood on which the mushroom grows, and it takes the form of a dense tangle of featherlike strands that are also waterproof. Combined with tiny wood cellulose fibers called nanofibrils (used in paper-making) it was utilized to create an oxygen-, oil- and grease-proof surface.
“Our hope is that by providing more ways to potentially reduce our reliance on single-use plastics, we can help lessen the waste that ends up in landfills and the ocean; nature offers elegant, sustainable solutions to help us get there,” says Assoc. Prof. Caitlin Howell, corresponding author of the study.
The fungus and wood fiber combination was applied in thin coats on the surfaces of two types of paper, denim, polyester felt and birch wood veneer, and left in an oven to dry for a day. An effective waterproof base about the thickness of a coating of paint was produced after three days of fungus growth in warm conditions, and by the fourth day the coating produced patchy yellow, orange or tan markings.
Water droplets that were subsequently placed on the coated materials beaded up into small spheres, whereas droplets placed on untreated surfaces spread out or soaked in completely. The fungal coating was also effective in preventing absorption of other liquids such as the fuel n-heptane, toluene-a solvent and castor oil, demonstrating great promise as an effective barrier against other liquids besides water.
Mycelium-based products are now becoming more prevalent in the field of building construction – at least on an experimental basis – such as oyster-mushroom-and-bamboo-based tiles made from leftover scraps, created by scientists from Nanyang Technological University in Singapore. The tiles resemble elephant skin with its bumpy knobby surface, and are designed to passively keep a building cool in hot months as well improve energy efficiency during cooler months.
Other mushroom tech in building construction includes mycocrete, a type of concrete made of mycelium and grains along with ingredients that provide bulk, in development at Newcastle University in Britain.
A paper on the University of Maine study was recently published in the journal Langmuir.
Source: American Chemical Society
