An extensive and systematic study of the intercalation of a number of commercially important anions into a range of layered double hydroxides (LDHs) has been undertaken. A pseudo-combinatorial approach was employed to determine rapidly the ideal reaction conditions for the intercalation of each guest. Over 50 LDH nanohybrids are reported, the vast majority of them having never previously been synthesized. Guest anions include key drugs, important agrochemicals, vitamins, fragrances, a dye, and a color fixant. The immense potential of LDH systems as reservoirs and to remove agrochemical pollutants from effluvium flows was demonstrated. The release of the guest anions was studied in representative conditions. Some of the thiosulfate intercalates show temperature programmable release characteristics which have not be observed previously.

Chlorophenoxyacetic acids are a well known family of herbicides. 4-Chlorophenoxyacetate (4-CPA), 2,4-dichlorophenoxyacetic (2,4-D), 2,4,5-trichlorophenoxyacetate, (2,4,5-T) have been intercalated into [LiAl 2 (OH) 6 ]Cl?xH 2 O LDH ([Li-Al-Cl] LDH) by ion-exchange. The kinetics and mechanisms involved in the intercalation of each chlorophenoxyacetate have been studied by time-resolved in-situ energy dispersive X-ray powder diffraction (EDXRD). The kinetic preferential order of the intercalation of these herbicides into [Li-Al-Cl] LDH is found to be 4-CPA . 2,4-D . 2,4,5-T. In contrast, thermodynamic guest preference, as determined by performing competitive intercalation reactions is 2,4-D . 4-CPA . 2,4,5-T. The results indicate chlorophenoxyacetate-LDH compounds could have application for the purification, storage and release of chlorophenoxyacetic acid-based agrochemicals.

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