July 28, 2008 A multi-institutional team of scientists has used
beamline 9.0.1 at the Advanced Light Source to perform high-
resolution x‑ray diffraction imaging of an aerogel for the first
time, revealing its nanoscale three-dimensional bulk lattice
structure down to features measured in nanometers, billionths of
a meter. Aerogels, sometimes called "frozen smoke" or "San
Francisco fog," are nanoscale foams: solid materials whose
sponge-like structure is riddled by pores as small as nanometers
across and whose strength is surprising, given their low
density. Many porous materials are extraordinary for their
properties as insulators, filters, and catalysts; they are used
to produce clean fuels, to insulate windows and even clothing,
to study the percolation of oil through rock, as drug-delivery
systems, and even to cushion the capture of high-velocity comet
fragments in outer space. "The smallest pore size is the key to
the strength of porous materials and what they can do," says
Stefano Marchesini, an ALS scie