What are Aggregated Diamond Nanorods?
The least compressible material known, with a bulk modulus of 491 gigapascals (GPa) is aggregated diamond nanorods. Aggregated diamond nanorods are what you get when you compress buckytubes, an allotrope of carbon, at 20 GPa, under a temperature of 2500 Kelvin, using a 5000 metric ton anvil press designed specifically for the purpose. The end result is a spaghetti of interconnected diamond nanotubes, with diameters between 5 and 20 nanometers and lengths of about a micrometer each. A bulk modulus of aggregated diamond nanorods, 491 GPa, is about three times of that of iron, which is 160 GPa. Conventional diamond has a bulk modulus of 442 GPa. A bulk modulus of 491 GPa means that a pressure increase of 49.1 GPa would be necessary to compress the aggregated diamond nanorods by a factor of 10%. A 98.2 GPa pressure increase would be necessary to increase it by 20%, and so on. For comparison, pressure at sea level (one atmosphere) is equal to about 100 kPa (kilopascals), and every ten meter
