Experimental design investigation for vermiculite modification: Intercalation reaction and application for dye removal

With the aim to improve the anionic dye sorption capacity of vermiculite, ethylenediamine was employed to modify vermiculite under different conditions. In this study, a 24 factorial design was used for organovermiculite preparation to assess the influence of the temperature (303 and 323K), ethylenediamine concentration (0.1 and 0.2molL−1), reaction time (24 and 48h) and acid activation of the clay mineral (leached and non-leached samples). The pristine and modified solids were characterized by CHN elemental analysis, infrared spectroscopy and X-ray diffraction. Principal component analysis and hierarchical cluster analysis were performed on the IR spectra to investigate the effect of parameter variation on the vermiculite modification. The reaction temperature and the acid activation of the vermiculite significantly influenced the vermiculite structural features. The optimized sample presented good adsorption capacity for Remazol Brilliant Blue RN, 11.02mgg−1. This study concluded that vermiculite modified with ethylenediamine behaved as a good sorbent to anionic dye. [Display omitted] •Ethylenediamine intercalation in vermiculite optimization via experimental design•Enhanced properties and applications by exploiting the optimal conditions•FTIR evaluation through principal component analysis and hierarchical analysis•Good adsorption capacity of anionic Remazol Brilliant Blue RN dye•Chemometrics as a powerful tool for enhancing Clay properties