Organic Crystal Templating of Hollow Silica Fibers

The incipient crystallization of needlelike forms of organic salts, such as ammonium dl-tartrate or ammonium oxalate, has been used for the templating of sol−gel reactions to produce hollow silica fibers and filaments with geometrically shaped channels. By judicious control of both the crystallization and hydrolysis−condensation processes, flexible tubes with continuous wall structures, often only 30 nm in thickness, can be produced.