Preparation of Superfine Ni and Fe Fibers by the Organic Gel-Thermal Reduction Method
Shen Xiangqian, Jing Maoxiang, Wang Taoping, Cao Kai (Jiangsu University, Zhenjiang 212013, China)
Superfine metallic nickel and iron fibers were prepared using the citric acid, lactic acid and their metal salts as the raw materials by organic gel-thermal reduction method. The superfine metallic nickel and iron fibers have diameters of less than 1μm and length of 2 m for nickel fibers and 0.5 m for iron fibers, and the fine crystalline particles of less than 100 nm. The structure, thermo-decomposition process and surface morphologies of the fibers derived from thermal reduction of the gel precursors were characterized by FTIR, XRD, TG/DSC and SEM. It is found that the gels showed a good spinnability, largely depends on the molecular structures of carboxylates formed in the gel. It is reasoned that these gels may consist of linear-type structural molecules [(C6H6O7)Ni]n for the nickel citrate gel, and [C3H4O3]3Fe for the ferric lactate gel, respectively. Moreover, the nickel citrate gel exhibited a better spinnability than the ferric lactate gel possibly due to the bridging behavior of Ni2+ ions during reactions between citric acid and nickel ions.