Sol-gel derived organic-inorganic hybrid ceramic materials for heavy metal removal

Abstract

Modification of the silica surface leads to the change in chemical composition of the surface which can be modified either by physical treatment (thermal or hydrothermal) or by chemical treatment. Such modifications significantly affect the adsorption properties of the materials and especially mechanical stability and water insolubility, increasing the efficiency, sensitivity and selectivity of the analytical application. A variety of types of organic polymers can be employed in the synthesis of hybrids with silica. One of them is chitosan. Chitosan and silica as well as their composites have attracted a great attention as effective hybrid biopolymeric sorbents due to high sorption capacity, cost-effectiveness, renewability and high stability. Owing to the presence of amino groups, chitosan is cationic and capable of heavy metal ions bonding. Several studies have reported on the metal ions removal of using chitosan or chitosan adsorbed onto conventional silica. Their short characterization is presented in this chapter. Moreover different ways of silica–chitosan composites are also discussed.