INFLUENCE OF PRECURSOR ADDITION AND REACTION ENVIRONMENT ON THE SYNTHESIS OF MESOPOROUS ALUMINA FOR ADSORPTION OF BOVINE SERUM ALBUMIN

Abstract

We employed AlCl3 and NaAlO2 and instituted different precursor addition modes with a syringe pump to synthesize mesoporous alumina (MA). The results showed that amorphous boehmite was produced from the syringe pump whilst crystalline bayerite was obtained from the usual freehand addition. AlCl3 with NaOH yielded products with smaller particle sizes and larger surface areas, but NaAlO2 with HNO3 gave products with better particle morphology and pore properties (pore volume and pore size). Reverse addition mode offered products with the largest surface areas (426.50m2/g) for both aluminium salts, whereas products with the lowest surface areas were from the direct addition mode. The MA products used as bio separator could adsorb and desorb bovine serum albumin (BSA) effectively. These results suggest that for applications in processes dependent on the surface area, the MA must be produced by the addition of AlCl3 solution into NaOH solution using a syringe pump. However, for applications in processes sensitive to pore size and volume, the MA must be produced by the addition of NaAlO2 solution into HNO3 solution. These findings may shape the choice for future reaction routes to inspire syntheses of MA products with customized and tailored properties for application in specific processes such as catalysis, adsorption, loading, encapsulation, bone and teeth replacement and catalyst immobilization.