In this research, the nano-iron oxide via sol-gel method was synthesized, Using Fe(NO 3 ).9H 2 O, ethanol and propylene oxide as gelation agent. The produced gel was washed with ethanol via Soxhelt method for 4 days. Then gel was dried in vacum oven for 6 days at 70? C.Subsequently, the synthesized gel was characterized using SEM, EDX, TEM, FTIR, BET and TG / DTA. The results of these analyses confirm the existance of amorph iron oxide, water, ?-Fe 2 O 3 , ?-Fe 2 O 3 , ?-FeO(OH) and Fe(OH) 3 in this mixture. The morphology of these particles show that they are spherical and agglomerate because of high reactivity and high surface area. In order to enhance the purity of oxidizer, some of the powder was heat treated at 410? C but the particle enlargement was observed. According to TG analysis, the purity of nano oxide is reported to be 96 % consisting of mainly ?-Fe 2 O 3 . At the same time, some of the powder was dried at 120? C and particle size in this temperature was smaller than those obtained at 410? C. But the impurity of the nano particles was higher at 120? C with respect to 410?C. According to BET analysis, heat treatment resulted in a growth of particle size and a reduction in surface area. The oxidizer purity was calculated to be 79 % at 120? C consisting of ?-Fe 2 O 3 and a little ?-Fe 2 O 3 . The two synthesized oxidizers at 120? C and 410? C were separately mixed with 100nm Al via ultrasonification using -Hexane for 60 sec. The mixing process was carried out with different stoichiometric ratios of oxidizer and fuel as follows: (1) 1: 2, (2) 1: 2.4 (3) 1: 3 and (4) 1: 4,respectively. Thus, the number with nano-Fe 2 O 3 and different percentages of nano-Al as 20 % results of TEM analysis demonstrated that the morphology of produced nanocomposites are spherical with particle size of less than 200 nm. The results of DTA showed that the reaction temperature was in the range of 500-600 ? C and XRD analysis indicated that the final products of this reaction are Fe and Al 2 O 3 . The combustion velocity experimentation proved that the stoichiometric ratios of (a) 1: 2.2, (b) 1: 2.9 had much higher combustion velociy compared to (c) 1: 2, (d) 1: 4. Obviously, increasing the amount of nano-Al in the synthesized nanocomposite with bimodal fuel led to higher combustion velocity. Keywords : Sol –gel, Nano iron oxide, Nano Al, Energetic nanocomposite
