Sorption of Bisphenol A as Model for Sorption Abilityof Organoclays

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Résumé

The arrangement of bisphenol A molecules into organoclays and their interactions withthe intercalated surfactant were studied. The organoclays were prepared via solid-state intercalationof four cationic surfactants, such as dodecyltrimethyl-, tetradecyltrimethyl-, hexadecyltrimethyl-,and didodecyldimethyl-ammonium, as bromide salts, at different loading levels into the interlayersof two natural clays. The natural clays, the prepared organoclays, and the spent organoclays werecharacterized by X-ray powder diffraction, infrared spectroscopy, and scanning electron microscopy.X-ray powder diffraction measurements showed successive interlayer expansions of the d001basalspacing due to the intercalation of the cationic surfactants and the bisphenol A sorption. Theincreased d001basal spacing of the organoclays after bisphenol A sorption indicates that the moleculesare integrated between the alkyl chains of the surfactant in the organoclays interlayers. Infraredspectroscopy was employed to probe the intercalation of the cationic surfactants and the sorbedbisphenol A. New characteristic bands attributed to the bisphenol A phenol rings appear in the range1518–1613 cm−1on the infrared spectra of the spent organoclays, proving the presence of bisphenol Ain the hydrophobic interlayers. Scanning electron microscopy of the organoclays before and after BPAsorption shows that their morphology becomes fluffy and that the presence of the organic moleculesexpands the clay structure.

Mots-clés

smectite; organoclays; surfactant; intercalation; hydrophobicity; rearrangement; expansion; interaction; partitioning process; Ca-montmorillonite