Influence of manufacturing variables on surface properties and dynamic adsorption properties of silica gels

The surface properties of silica gel such as surface area, pore volume, and average pore diameter are affected by the manufacturing variables including FH values, gelling and dehydration temperatures. The dynamic adsorption properties of silica gel are also affected by their preparation conditions. The mass transfer zone and the amount of adsorption were discussed using the experimental data of breakthrough curve. The influence of the manufacturing variables on the trends of breakthrough curves is important in most of the adsorbent modification. It was found in this study that the manufacturing variables affected the adsorption performance significantly. Therefore, the relationship between the manufacturing variables and the corresponding adsorbent properties conducted by the dynamic adsorption apparatus was examined in this study. This discussion is rare in most of the studies of preparing silica gels, which are usually focused on the relationship between the manufacturing variables and the surface properties of silica gels only. However, it is not necessary that a silica gel with larger surface area will give a smaller mass transfer zone or mass transfer resistance. The modification of adsorbents should consider not only the improvement of their surface properties but also their adsorption performance. (C) 2001 Elsevier Science B.V. All rights reserved.