Effect of framework and textural porosities of functionalized mesoporous silica on metal ion adsorption capacities

The effects of the framework and/or textural porosities and functional group densities of the functionalized HMS on the metal adsorption capacities were examined. Mercapto concentration was weakly correlated with pore size and the surface area of the supports, but was strongly dependent on the framework pore volume. In case of adsorbents with a well-developed framework porosity, the uptake of mercury ions increased with an increase in mercapto concentration, while adsorbents with a well-developed textural porosity show a slight increase with mercapto concentration. The characteristics of lead ions showed a similar absorption trend to that of mercury ions. The results showed that the amounts of metal ion uptake of SBA having long range 2-D pore channels were less than those of HMS having short range interconnected 3-D pore channels.