Preparation and characterisation of novel paddy cultivation herbicide nanocomposite from zinc/aluminium layered double hydroxide and quinclorac anion

摘要

Zn/Al-layered double hydroxide-quinclorac (Zn/Al-LDH-QC) nanocomposite has been synthesisedvia co-precipitation method. The versatility of the Zn/Al-LDH enables this host material to beintercalated with quinclorac (QC), a type of auxin agonist herbicide that was widely used in paddycultivation. The PXRD analysis shows that the basal spacing of the Zn/Al-LDH-QC nanocompositeexpanded in the range of 15.8-16.7 Å (from 8.8 Å in Zn/Al-LDH), therefore indicating the successfulintercalation of QC into the interlayer gallery of Zn/Al-LDH. The intercalation was also proven fromthe FTIR and elemental analysis. The thermogravimetric analysis conducted using TGA/DTG showsthat the Zn/Al-LDH-QC exhibits better thermal stability compared to the pure QC herbicide. Basedon the results collected from the ICP-OES, CHNS analyser, and TGA/DTG, the chemical formulaof Zn/Al-LDH-QC was proposed as [Zn_(0.75)Al_(0.25)(OH)_2][C_9H_4Cl_2NCOO]−_(0.25)0.90H_2O. This study showsthat the Zn/Al-LDH has potential to be used as a host material for herbicide in paddy cultivationsector.