Synthesis of dual herbicides-intercalated hydrotalcite-like nanohybrid compound with simultaneous controlled release property

Abstract

A new monophasic nanohybrid containing two herbicides anions, 3,4-dichlorophenoxyacetate (3,4D) and 2-methyldichlorophenoxyacetate (MCPA), was successfully synthesized. The two anions were simultaneously intercalated into the inorganic interlayers of zinc-aluminiumlayered double hydroxide (ZAL) for the formation of a nanohybrid, ZAL-MCPA-3,4D (ZAMDX) by anion exchange method. The properties of ZAL intercalated with single guest MCPA and 3,4D, as well as dual-guest nanocomposite were monitored using powder X-ray diffractometer (PXRD), and showed a basal spacing of 19.7, 19.0 and 19.2 Å, respectively. Direct-injection mass spectroscopy (DIMS) and Fourier transform infrared (FTIR) confirmed the dual intercalation of both anions into the interlayer regions of dual-guest nanocomposite. The release of MCPA and 3,4D from ZAMDX fitted a pseudo-second order model and possessed good controlled release properties. This release property exhibits the potential application of layered materials as a delivery system, as well as reservoirs, especially when multiple active agents are used simultaneously in the formation of an organic-inorganic hostguest nanohybrid.

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“…From the pattern of MAN host, a very intense and sharp peak was appeared with the basal spacing of 8.9 Å. This basal spacing was contained water molecules and nitrate as counter anions between its interlayer gallery that had been reported previously by [10][11][12]. The water molecules were attached to the nitrate and metal hydroxide through extensive hydrogen bonds that would continuously breaking and forming into the new bond.…”

“…Layered nanomaterials such as LDH are widely study among researcher due to their unique properties and it has been used in diverse applications such as adsorbents, drug delivery [1], controlled release formulation [2][3] and sensors [4]. LDH has capability as a host to construct organic-inorganic nanomaterials due to high stability and less toxicity properties [5].…”

Physicochemical Characterization and Controlled Release Formulation on Intercalated 2-Methyl-4-chlorophenoxy Acetic Acid-Graphite Oxide (MCPA-GO) Nanocomposite

“…The MCPA-GO nanocomposite was done by using ion-exchanged method [1]. This method was run under the room temperature.…”

“…The expansion of the interlayers of the nanocomposite with only single peak present has confirmed the inclusion of herbicide anion, MCPA during intercalation process. This extent of expansion may be due to several factors such as the anionic size of herbicide, charge, orientation, and interaction between graphite oxide and herbicide [1]. Theoretically, the intercalation of MCPA with graphite oxide involved non-covalent dynamic bonding interactions such as hydrogen bonding, π-π stacking, and electrostatic forces bounding to each other due to the presence of oxygen groups as the reactive sites [16].…”

“…According to the Environmental Protection Agency (EPA) in the United States, 2-methyl-4-chlorophenoxy acetic acid (MCPA) is an example of herbicide that was sold approximately 4.6 million pounds each year for agricultural and residential usage. MCPA is a specific systemic chemical herbicide that applied to kill or inhibit the growth of specific plants such as noxious weed plant in cereals, wheat, rice, corn, peas, potatoes and grasslands [1]. However, the environmental problems arise once the residue of herbicide being swept away by rain that leads to soil pollution, strong water pollutant and they difficult to degrade and can rapidly move around [2][3].…”