Preparation of Al₂O₃@TiO₂ biological composite support and adsorption of bovine serum albumin

A series of Al₂O₃@TiO₂ composite supports were prepared and they were covered with a layer of mesoporous TiO₂ by using titanate sol or titania sol. The differences of structures and properties of two TiO₂ samples and their influences on adsorption of bovine serum albumin (BSA) were analyzed. The pore sizes of three alumina supports were 0.37, 10.4 and 21.8 μm respectively. The results of XRD and Raman spectroscopy showed that both TiO₂ samples were anatase phase. In addition, N₂ adsorption-desorption isotherms showed that two samples had similar surface area [(100±10) m²·g^-1] and mesoporous structure. Moreover, FESEM image indicated that the morphologies of TiO₂ prepared from potassium titanate sol were affected by pore diameter of Al₂O₃ support. BSA adsorption performance indicated that the adsorption capacity of 20 μm Al₂O₃@TiO₂ composite support prepared with potassium titanate sol (SP20@K-TiO₂) was 22.18 mg·g^-1, higher than the same size composite support prepared with titania sol. The adsorption capacity of TiO₂ in SP20@K-TiO₂ waps 150.88 mg·g^-1. Compared with TiO₂ powder, the BSA adsorption performance of TiO₂ in the composite support was promoted.