AUTHOR=Zhang Xiaoguang , Liu Jiexiang , Ren Jihui 

TITLE=Structure and release properties of pyrethroid/sulfobutyl ether β-cyclodextrin intercalated into layered double hydroxide and layered hydroxide salt

JOURNAL=Frontiers in Chemistry

VOLUME=Volume 10 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2022.894386

DOI=10.3389/fchem.2022.894386

ISSN=2296-2646

ABSTRACT=The aim of this paper is to realize the intercalation of pesticides pyrethroid of beta-cypermethrin (BCT) and lambda-cyhalothrin (LCT) into ZnAl-layered double hydroxides(LDH) and NiZn-layered hydroxide salt (LHS). BCT(LCT)/SBECD-LDH and BCT(LCT)/SBECD-LHS hybrids are obtained with the aid of sulfobutyl ether β-cyclodextrin (SBECD) through one step method. The hybrids were characterized by powder X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR), and thermal gravimetry and differential thermal analysis (TGA/DTA). The hybrids based on LHS had the larger basal spacing than those on LDH. The LDH-hybrids prepared in N-methylpyrrolidone (NMP) had the larger basal spacing than those in ethanol. These results were discussed from the matrix structure and solvent properties. The supramolecular structure of the hybrid was reasonably proposed. Furthermore, the release properties of BCT (LCT) from the hybrids were investigated and discussed in two mediums. The release rate in pH=5.0 was slower than that in pH=6.8. The accumulated release amount of pesticide in pH=5.0 was lower than that in pH=6.8. LHS-hybrids synthesized in ethanol exhibit a sustainable release property. These depended on the inclusion complexes arrangement and release medium. The release kinetic processes could be described with pseudo second-order and parabolic diffusion models. The release behavior can be controlled by adjusting the synthesis conditions and the releasing media. This provides the guidance for the application of SBECD and LDH (LHS) in pesticide formulation.