LAUSR

Abstract Taguchi M32 experimental design was implemented to investigate the effect of operating variables on the structural and textural properties γ-alumina granules produced via the oil-drop route. Aluminum powder and hexamethylenetetramine (HMTA) were used as precursor and gelling agent, respectively. Nitric acid (HNO3) was tested to dissolve aluminum powder as a novel digestive media. Response surface methodology (RSM) was employed to analyze the results of experimental design. The synthesized samples were characterized, by Thermo-gravimetric analysis (TGA/DTA), X-ray diffraction (XRD), nitrogen physisorption, energy dispersive X-ray (EDX), scanning electron microscopy (SEM), and transmitting electron microscopy (TEM). The output of RSM which is a multivariate linear regression model was examined to find out the effect of each factor on the response, namely the total surface area of γ-alumina granules to reach the optimum conditions. The optimized samples possess superior characteristics, e.g. highest surface area, magnificent sphericity, mesoporous structure, monotonous crystalline network, and broad pore size distribution. Based on the results, the surface area of γ-alumina granules relied too much on the temperature of aging solution, aging time and interactions between the factors. The role of heat treatment on the texture properties and morphology evolution of the samples were also precisely discussed.