Synthesis of new porous clay heterostructures: The influence of co-surfactant type

The effect of co-surfactant type on the properties of porous clay heterostructures (PCH) was investigated by using FTIR, TGA, XRD, TEM and nitrogen adsorption-desorption isotherms. Two commercial polyetheramines (B100 and B200) with different structures and hydrophilic-lipophilic balance (HLB) values were proposed as new co-surfactants for the synthesis of PCH. Textural properties characterization suggested that the PCH samples exhibit higher values of specific surface area (420-655 m(2)/g) and a substantially increase of total pore volume (0.59-1.01 cm(3)/g) than starting clay (MMT-Na). The specific surface area, total pore volume and pore size distribution were significantly influenced by the type of co-surfactant. FTIR analysis revealed the presence of isolated and also associated terminal silanol groups in all PCH samples. Thermogravimetric measurements showed that all PCH samples exhibit similar thermal behavior, indicating the presence of a dehydroxylation process that involves hydroxyl groups located between MMT tetrahedral sheets and hydroxyl groups located in the pillars. The PCH synthesized using polyeteramines as co-surfactant were characterized by predominantly exfoliated structures as revealed by XRD and TEM analysis. TEM analysis highlighted the presence of porous structure of PCH with various pores shapes and dimensions. The polyetheramines exhibit a different co-template effect due to the different HLB and molecular weight values. (C) 2016 Elsevier B.V. All rights reserved.