The Effect of Zinc to Aluminium Molar Ratio on the Physico-Chemical Properties of Zinc-Aluminium-3,4-Dichlorophenoxy Acetate Nanocomposite

Abstract

Layered double hydroxide (LDH) hybrid materials of Zn-Al-layered double hydroxide-3,4-dichlorophenoxy acetate acidnanocomposites (ZADs) were prepared by direct self-assembly method. The pH of the solution was adjusted to 7.5 using 2M NaOH. Various Zn2+ to Al3+ molar ratios, R ranging from 1 to 6 were used with a fixed concentration of 3,4-D at 0.3 M. The Powder X-ray diffraction (PXRD) patterns showed the formation of well-ordered nanocomposite with the expansion of basal spacing from 8.9 Å in the Zinc-Aluminium-Layered Double Hydroxide (ZAL) to 18.7 - 22.1 Å in the resulting nanocomposites. The Fourier transform infrared (FTIR)spectra for the nanocomposites showed features for both ZAL and ZAD, showing the successful intercalation of the organic moiety into the LDH interlayer. The percentage loading of 3,4-dichlorophenoxy acetati acid(3,4-D) in LDH was found to be increased from 34.7-48.1 % (w/w), as the mole fraction of Al decreased from 0.44-0.15. This study shows that the mole fraction of zinc ion was replaced by aluminium ion in the LDH plays an important role in controlling the physic-chemical properties of the resulting material.