Lysozyme and BSA were used, as model proteins of considerably different dimensions, in
order to evaluate the influence of the distinct pore structural characteristics of three types of ordered
mesoporous silica materials (MCF, SBA-15 and MCM-41) on protein adsorption. Characterisation
by X ray diffraction and nitrogen adsorption at 77K revealed the typical pore structural features of
each type of material. The maximum of the pore size distributions indicated that the width of the
windows of MCF (2) (mesitylene/P123 of 2) was larger than the pore diameter of the unidirectional
tubular pores of SBA-15. All the materials presented similar small external surface areas but high
pore volumes, with that of MCF (2) being the highest. The adsorption of lysozyme at pH=8
increased in the order MCM-41<< SBA-15< MCF (2), and the uptakes were well above those of
BSA at pH=5. Although BSA is not completely excluded from the mesopores of SBA-15 and
MCF (2), as happens with MCM-41, the adsorption occurs to a very limited extent. The overall
behaviour of these SBA-15 and MCF (2) samples was not significantly different and both revealed
potential for the separation of these proteins