Hydrophobic Aerogel Makes Hands Waterproof
Channel: aerogeltech
Date: 18/10/2012

Aerogels are ultralow-density solids with incredible materials properties including unmatched thermal insulating abilities and ultrahigh surface area.  Unfortunately, many aerogels are damaged when contacted by water.  Aerogels can be made impervious to water, however, by chemical treatment to render them hydrophobic.  An aerogel is essentially a dry, porous sponge-like framework with nanosized pores.  Lining the struts of this framework are hydroxyl (-OH) groups that attract water.  By reacting these hydroxyl groups with a waterproofing agent such as hexamethyldisilazane, the hydroxyl groups can be converted to trimethylsilyl groups which are non-polar and repel water.

In this video, the water-repelling properties of hydrophobic silica aerogels are demonstrated by using aerogel to waterproof a scientist's hands.  By crushing hydrophobic silica aerogel particles into a powder and coating his hands with the powder, the scientist can submerse his hands under water without getting them wet!

Filmography and production by Steve Boxall (www.stephenboxall.com) .