PAN immobilized organo nanoclay as a new sorbent for green separation of trace amounts of Cu2+, Ni2+and Mn2+ ions

Clay and clay minerals have primary particles with at least one dimension in the nanometer scale; they may be regarded as nanomaterials of geological and pedological origins [1]. Smectites are an important class of clay minerals because of their specific properties such as a high cation-exchange capacity, adsorption, high surface area and swelling behavior. The most common dioctahedral smecite is montmorillonite, a 2:1 layer phyllosilicate constituted from an octahedral sheet located between two tetrahedral SiO2 sheets. In tetrahedral sheets Si (IV) atoms can be replaced by Al (III) while in the octahedral sheets Al (III) atoms are substituted with Fe (III) or Mg (II), producing negatively charged layer. The charge imbalance due to isomorphic substitution in the layer is compensated by exchangeable cations located in interlamellar positions or on the particle surface [2]. Normally, organic surfactants are used to make the surface of clay platelets organophilic and swell the clay galleries. An organophilic surface and interlayer environment can be produced by replacing naturally occurring inorganic exchangeable cations with a variety of organic cations; for example, long chain alkylammonium ions [3]. These modified organoclays, are used in a wide range of particular applications, such as adsorbents for organic pollutants [4] and metal ions [5], reinforcing filler plastics [6] and catalysts [7]. The present study reports the application of organo nanoclay 1-(2-pyridylazo) -2- naphtol (PAN) immobilized as a new, easily prepared and stable solid sorbent for preconcentration of trace amounts of Cu2+, Ni2+ and Mn2+ ions in aqueous solution. The organo nanoclay was prepared by adding tetradecyldimetylbenzylamonium chloride (TDMBAC) onto montmorillonite and then was saturated with PAN. In this work, a simple, rapid, selective, sensitive and economical method has been developed for the simultaneous separation of trace amounts of copper, nickel and manganese in aqueous medium using PAN as an analytical reagent.