NOVELTY - Preparation (P1) of a cross-linked sol-gel like material involves contacting a sol-gel like material with a cross-linking agent.    USE - For the preparation of a cross-linked sol-gel like material useful for preparing cross-linked aerogel e.g. silica aerogel, which are useful in a capacitor, dielectric, an electrical circuit, thermal insulating material and structural materials. The thermal insulating material is used in a tile, door, panel, shingle, shutter, beam, cooler, article of clothing, shoe and boot (all claimed). The doors include refrigerator and oven doors. The panel includes insulation panels. Also useful as light-weight building materials, or to reinforce plastics and other materials used in construction; to produce more durable optical sensors, such as those used to detect oxygen; in the preparation of radiation detectors; in fuel storage cells; to provide structural support as well as protection against fires; as supports, such as for absorbents and catalysts; as a dimensionally stable electrode material for electrolysis; in the field of superconductivity; in the automotive and aerospace industry e.g. automotive and aircraft panels, seats, flooring, handles, levers; and for creating protective clothing such as bullet-proof vests, jackets, and helmets; and in heat resistant clothing articles. The structural materials includes materials for the production of building materials such as ceiling tiles, floor tiles, doors, paneling, shingles, shutters and beams.    ADVANTAGE - The cross-linked aerogel is less brittle than native silica. The cross-linked aerogel does not collapse when in contact with a liquid containing water, an alcohol, an ether, a hydrocarbon, (preferably kerosene, gasoline, jet fuel or rocket fuel), an ester, a ketone, a carboxylic acid, a phosphoric acid, or a liquefied gas such as nitrogen, argon, helium, hydrogen or oxygen.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following:    (1) a method to link an attached group to an aerogel involving contacting a sol-gel like material with a cross-linking agent that includes the attached group to form a cross-linked sol-gel like material and drying the cross-linked sol-gel like material from the aerogel; and    (2) a method (m1) to dry a cross-linked aerogel involving washing the cross-linked aerogel in a solvent (S1) to form a washed aerogel and drying the washed aerogel under non-supercritical conditions.