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A platform for research: civil engineering, architecture and urbanism
Fe-pillared clay mineral-based formulations of imazaquin for reduced leaching in soil
Abstract Slow release formulations of the herbicide imazaquin (2-(4-isopropyl-4-methyl-5-oxo-4,5-dihydro-1H-imidazol-2-yl)quinoline-3-carboxylic acid) were prepared by its adsorption on Fe-pillared clay minerals (Fe PILCs). Fe PILCs were synthesized by the reaction of Na+-montmorillonite (SWy-2) with base-hydrolyzed solutions of Fe and Al. The Fe/(Fe+Al) ratios used were 0, 0.05, 0.15 and 0.50. Fe PILCs showed basal spacing values of 5.2 and 1.8nm which were due to iron clusters between delaminated clay layers, and intercalated aluminum polyoxocations, respectively. As iron content increased, the pillaring process yielded PILC with lower microporosity and larger mesoporosity. The affinity of imazaquin on Fe PILCs was very high relative to Al PILC, as revealed in its higher herbicide adsorption values and lower desorption percents. Competitive adsorption of anions such as sulfate, phosphate and chloride provided evidence of formation of inner sphere complexes of imazaquin on Fe PILCs. Slow release formulations were prepared by enhanced adsorption of the herbicide from imazaquin–cyclodextrin (CD) complexes in solution. CDs were able to enhance up to 8.5-fold the solubility of imazaquin, by the formation of inclusion complexes where the quinolinic moiety of the herbicide was partially trapped within the CD cavity. Release of the herbicide in sandy soil was about 1/2-fold lower from Fe PILC formulations relative to the commercial formulation.
Highlights Iron oxide pillared clays (Fe PILCs) were synthesized and characterized. Imazaquin (IMZQ) solubility was enhanced by the use of cyclodextrins (CDs). The quinolinic moiety of the herbicide was trapped inside the CD cavity. Sorption of the herbicide on Fe PILC increased largely from CD–IMZQ complexes. Fe PILC-based formulations of IMZQ retarded the release of the active ingredient.
Fe-pillared clay mineral-based formulations of imazaquin for reduced leaching in soil
Abstract Slow release formulations of the herbicide imazaquin (2-(4-isopropyl-4-methyl-5-oxo-4,5-dihydro-1H-imidazol-2-yl)quinoline-3-carboxylic acid) were prepared by its adsorption on Fe-pillared clay minerals (Fe PILCs). Fe PILCs were synthesized by the reaction of Na+-montmorillonite (SWy-2) with base-hydrolyzed solutions of Fe and Al. The Fe/(Fe+Al) ratios used were 0, 0.05, 0.15 and 0.50. Fe PILCs showed basal spacing values of 5.2 and 1.8nm which were due to iron clusters between delaminated clay layers, and intercalated aluminum polyoxocations, respectively. As iron content increased, the pillaring process yielded PILC with lower microporosity and larger mesoporosity. The affinity of imazaquin on Fe PILCs was very high relative to Al PILC, as revealed in its higher herbicide adsorption values and lower desorption percents. Competitive adsorption of anions such as sulfate, phosphate and chloride provided evidence of formation of inner sphere complexes of imazaquin on Fe PILCs. Slow release formulations were prepared by enhanced adsorption of the herbicide from imazaquin–cyclodextrin (CD) complexes in solution. CDs were able to enhance up to 8.5-fold the solubility of imazaquin, by the formation of inclusion complexes where the quinolinic moiety of the herbicide was partially trapped within the CD cavity. Release of the herbicide in sandy soil was about 1/2-fold lower from Fe PILC formulations relative to the commercial formulation.
Highlights Iron oxide pillared clays (Fe PILCs) were synthesized and characterized. Imazaquin (IMZQ) solubility was enhanced by the use of cyclodextrins (CDs). The quinolinic moiety of the herbicide was trapped inside the CD cavity. Sorption of the herbicide on Fe PILC increased largely from CD–IMZQ complexes. Fe PILC-based formulations of IMZQ retarded the release of the active ingredient.
Fe-pillared clay mineral-based formulations of imazaquin for reduced leaching in soil
Undabeytia, T. (author) / Galán-Jiménez, M.C. (author) / Gómez-Pantoja, E. (author) / Vázquez, J. (author) / Casal, B. (author) / Bergaya, F. (author) / Morillo, E. (author)
Applied Clay Science ; 80-81 ; 382-389
2013-07-07
8 pages
Article (Journal)
Electronic Resource
English
Fe-pillared clay mineral-based formulations of imazaquin for reduced leaching in soil
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