Silica Sol as a Nanoglue: Flexible Synthesis of Composite Aerogels
Catherine A. Morris,
1*
Michele L. Anderson,
1
Rhonda M. Stroud,
2
Celia I. Merzbacher,
3
Debra R. Rolison
1
Low-density nanoscale mesoporous composites may be readily
synthesized by adding a colloidal or dispersed solid to an about-to-gel silica sol. The silica sol can "glue" a range of chemically and physically diverse particles into the three-dimensional silica network
formed upon gelation. If the composite gel is supercritically dried so
as to maintain the high porosity of the wet gel, a composite aerogel is
formed in which the nanoscopic surface and bulk properties of each
component are retained in the solid composite. The volume fraction of
the second solid can be varied above or below a percolation threshold
to tune the transport properties of the composite aerogel and thereby
design nanoscale materials for chemical, electronic, and optical
applications.
1 Surface Chemistry (Code 6170),
2 Surface Modification (Code 6370), and
3 Optical Techniques (Code 5670) Branches, Naval
Research Laboratory (NRL), Washington, DC 20375, USA.
*
Participant from Annandale High School (Annandale, VA) in the
NRL Science and Engineering Apprentice Program, 1995-96
(cam32{at}cornell.edu).
To whom correspondence should be addressed. E-mail:
rolison{at}nrl.navy.mil
