© 2015 Elsevier B.V. All rights reserved. The goal of this work was to prepare and characterize a novel functional material by the modification of SAz-1 montmorillonite with the cationic polymer hexadimethrine (SA-HEXAD), and to explore the potential use of this nanocomposite as a pesticide adsorbent. Comparative preparation and characterization with the well-known hexadecyltrimethylammonium-modified SAz-1 montmorillonite (SA-HDTMA) was also assessed. The characterization was performed by elemental analysis, X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), physisorption of N2, scanning electron microscopy (SEM) and Z potential measurements. The characterization and adsorption experiments showed that the extent of pesticide adsorption was markedly subjected to the structure and features of the surface of each organo-clay and also to the nature of the considered pesticide. SA-HEXAD displayed a high affinity for anionic pesticides which, presumably, were adsorbed by electrostatic attraction on positively-charged ammonium groups of the polymer not directly interacting with the clay. In contrast, SA-HDTMA displayed great adsorption of both uncharged and anionic pesticides with predominance of hydrophobic interactions. This work provided information about the surface properties of a new organic-inorganic nanohybrid material, SA-HEXAD, and its potential as an adsorbent for the removal of anionic organic pollutants from aqueous solutions.

This work has been financed by the Spanish Ministry of Economy and Competitiveness (Grant AGL2011-23779) and Junta de Andalucía (Grants P07-AGR-03077 and P11-AGR-7400). B. Gámiz also thanks Junta de Andalucía for her postdoc-contract linked to Project P07-AGR-03077.

8 páginas.--7 figuras.-- 1 tablas.-- 66 referencias.-- Data Supplementary data associated with this article can befound, in the online version, at http://dx.doi.org/10.1016/j.apsusc.2015.01.179.

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