A group of scientists at the Naval Research Laboratory in Washington has demonstrated the use of silica sol as a nanoscale glue to prepare composite gels and aerogels. The discovery could lead to fabrication of nanoscale materials for electronic and optical applications. The researchers used silica sol to prepare composite gels by dispersing a colloidal or noncolloidal solid in silica sol right before it began to gel. They were able to construct silica structures with particles as small as 2 nm. The particles remained "glued" even after repeated washings and dryings. The paper appears in the April 23 issue of Science.