科学家让迷彩服防火耐热

Camouflage face paint can make a soldier invisible to enemy eyes. But it won't shield him from the searing heat of a roadside bomb, a lethal 1100 degrees Fahrenheit. And the greases and oils in the makeup just add fuel to the fire, essentially cooking the soldier's face. But now researchers have come up with a safer, heat-blocking alternative presented this week at a meeting of the American Chemical Society.

Conventional camo paint has tiny nanoparticles of pigment. They're great at reflecting visible light—which is why the paint looks green or black or tan. But the particles don't reflect longer wavelengths, like heat. To do that, you need larger globs of pigment.

So researchers bundled together a bunch of those smaller particles into chunks the size of grains of sand—large enough for heat rays to bounce right off. And they swapped out the grease for silicone which adds smoothness and spreadability to cosmetics, but won't catch fire.

Under a blowtorch, the new camo paint can block out heat for 15 seconds—long enough to weather a bomb blast, and keep soldiers cool in the heat of battle.

—Christopher Intagliata