Optimization of mesoporous alumina sol‐gel synthesis by Taguchi and response surface methodology

Abstract

Taguchi method (TM) and response surface methodology (RSM) have been employed to optimize three parameters, including the amounts of P123, the amounts of nitric acid and calcination temperature, in order to define an optimal setting for sol-gel synthesis of high surface area mesoporous alumina powder (MA). Herein, the comparison of the both statistical approaches has been examined and discussed considering the nitrogen adsorption as the response variable because this important character for mesoporous materials is exceedingly sensitive to the synthesis parameters. The BET surface area (S BET ) and pore volume of MA under Taguchi optimal condition were 323.5 m 2 g −1 and 0.551 cm 3 g −1 , respectively, by conducting confirmation test. Furthermore, the confirmation test showed high S BET of MA (363.4 m 2 g −1 ), which was in a good agreement with calculated S BET result (431.25 m 2 g −1 ) by a quadratic model under RSM optimal condition. Moreover, 3D response surface plots and 2D contour plots of desirability have been discussed to visualize the influence of input factors on response variable. It is also concluded that RSM shows more appropriate (12.33% higher S BET than TM) and efficient optimal condition with determining a quadratic function as the relationship between S BET and synthesis parameters. K E Y W O R D SBET surface area, design of experiments, mesoporous alumina, response surface methodology, sol-gel process, Taguchi method

Near‐net shape manufacture of macroporous nanosized alumina monolith by aqueous gel casting method

“…In order to better understand the interaction effects of different variables, three‐dimensional (3D) colormap surface plots are provided in Figure 11, demonstrating that the changes in bulk density values of sintered samples containing nano alumina fraction are a function of the alumina loading, monomer concentration (MAM + MBAM), and sintering temperature. The shape of 3D colormap surface plots indicates that the mutual interaction between the independent parameters is significant 15,40 . It can be also seen from Figure 11A that bulk density sharply increases by increasing both the alumina loading and sintering temperature.…”

“…The variety of application fields demonstrates the importance of macroporous structures. Besides the excellent properties of alumina, pore structure (pore size), pore size distribution, porosity volume fraction, tortuosity, the fraction of open, and interconnected pores are considered as important keys to construct a good macroporous architecture for efficient performance because porosity has a strong impact on the performance function definition 13‐15 . The final macroporous structure and mechanical properties of alumina monoliths are influenced not only by the manufacturing methods but also by the simultaneous effects of different preparation parameters.…”