Growth and structure of microscale fibers as precursors of alumina nanofibers

► There is a new technique of synthesizing two types of aluminum oxide nanofibers. ► A microscale fiber growth model with the use of alumina gels has been proposed. ► Ammonium chloride is the basic microscale fiber component. ► Calcination of the microfibers generates alumina nanofibers. ► The alumina fibers diameter is 100-150 nm and 50-90 nm.