The preparation of novel silica gel hollow tubes**

Abstract
Work‐like silica gel hollow tubes have been prepared using a sol‐gel method. The tubes (see Figure), wich are porous, mostly have one end closed, although occasionally tubes with both ends closed are produced. The preparation method, which involves the hdyrolysis of tetraethylorothosilicate in a mixture of ethanol, ammonia, water and citric acid monohydrate, is described magnified image .