Synthesis and characterization of 2,4-dichlorophenoxyacetic acid interleaved with calcium-aluminium layered double hydroxide by comparison of co-precipitation and ion-exchange method / Fatin Haizira Mohd Hayazi

By using co-precipitation method, the herbicide named 2,4-dichlorophenoxyacetic acid or known as 2,4-D was successfully interleaved with Ca-Al layered double hydroxide forming nanocomposite of 2,4-D-Ca-Al-LDH. There were two methodologies used which were co-precipitation method and ion-exchange method. Co-precipitation method has shown a successfully interleaved of the anion with the host compared to the ion-exchange method. The interleaved of 2,4- D with Ca-Al LDH happened at 0.05 M and can be confirmed by Power X-Ray Diffraction (PXRD) and Attenuated Total Resonance Fourier Transform Infrared (ATR FTIR). From the PXRD results, the successful intercalation happened when the basal spacing increased from 8.67 Å to 17.59 Å and a new sharp and intense peak was formed due to the insertion of guest anion which was 2,4-D into the interlayer region of Ca-Al LDH. Results from PXRD was supported by FTIR spectrum, where the nitrate peak that was at 1350.01 cm-1 was disappeared that proved the intercalation was successfully achieved. The peak at 1643.17 cm-1 to 1625.73 cm-1 indicated the presence of C=O stretching and a new peak value due to the asymmetric stretching vibration of COO- after interleaving process of 2,4-D into the inter gallery of Ca-Al LDH. From this research, the 2,4-D herbicide has been successfully interleaved into the interlayer region Ca-Al LDH using co- precipitation method at 0.05 M which is the optimum concentration for the successful intercalation of 2,4dichlorophenoxyacetic acid into Ca-Al LDH.