Structural changes in phenol-intercalated hydrotalcite caused by heating

Thermal analysis (DTA-TG-DTG), X-ray diffraction (XRD), Fourier transform i nfrared (FTIR) spectroscopy, nitrogen adsorption and mercury intrusion poro simetry techniques were used to assess the structural changes induced upon heating of two hydrotalcite-phenol (trichroro- and trinitrophenol, HT-TCP a nd HT-TNP) complexes, and the results were compared with those obtained for the original hydrotalcite (HT) sample. The DTA revealed thermal effects th at depended on the nature of the interlayer ion in the complexes. The total weight loss (TG-DTA) increased from 37% for the original HT to 40% for HT- TCP and 77% HT-TNP, as the amount of phenol increased. The XRD and FTIR spe ctroscopy showed that the calcination product (550 degreesC) of the MT-phen ol complexes was indistinguishable from that formed from the original MT. S ince HT-phenol complexes were prepared by phenol adsorption on calcined HT, our results confirm the recyclability of MT-like compounds as sorbents for phenols.