Mushrooms are suitable for sound insulation.
Spent coffee grounds, as a Chinese university research team just discovered, could be used to deliver sustainable thermal insulation. Initially, the grounds were converted into biochar at 700°C, increasing the granules’ porosity from 40% to 70%.
These cavities were then filled with a mix of environmentally-friendly solvents. This in turn prevented ethylcellulose, the binding agent added next, from entering the cavities.
The resulting mixture was pressed for 10 minutes at 150°C, then oven-dried for an hour at 80°C, causing the solvent to evaporate again.
The outcome: a porous, biodegradable material with insulating properties similar to polystyrene. Ideal for the circular economy.
Coffee grounds also pack a punch, and even give cement an extra kick.
