Precipitation is also useful to isolate the products of a reaction during workup. Ideally, the product of the reaction is insoluble in the reaction solvent. Thus, it precipitates as it is formed, preferably forming pure crystals. An example of this would be the synthesis of porphyrins in refluxing propionic acid.
Freebase(0.00 / 0 votes)Rate this definition: Cellophane. Cellophane is a thin, transparent sheet made of regenerated cellulose. Its low permeability to air, oils, greases, bacteria and water makes it useful for food packaging.
Cellophane packaging is an example of this new technology. Cellophane is the oldest transparent packaging product used to encase cookies, candies, and nuts. First marketed in the United States in 1924, cellophane was the major packaging film used until the 1960s.In the more environmentally-conscious market of today, cellophane is returning in popularity.ellophane is the oldest transparent packaging product used to encase cookies, candies, and nuts. First marketed in the United States in 1924, cellophane was the major packaging film used until the 1960s. In the more environmentally-conscious market of today, cellophane is returning in popularity.