Development of a novel nanocomposite consisting of 3-(4-methoxyphenyl)propionic acid and magnesium layered hydroxide for controlled-release formulation

Abstract

Magnesium layered hydroxide (MLH) intercalated with anionic 3-(4-methoxyphenyl)propionic acid (MPP) was synthesised by a direct reaction method using magnesium oxide and MPP as precursors. A further coating of chitosan was applied on the external surface of MLHÀMPP nanocomposite to form a new material, named MLHÀMPP/chitosan nanocomposite. The XRD pattern showed an intense and sharp peak at basal spacing 18.9 A , proving that MPP anions were successfully intercalated into the interlayer gallery of MLH in a monolayer arrangement. The XRD pattern of the MLHÀMPP/chitosan nanocomposite shows similar peaks with the MLHÀMPP nanocomposite. The result was also supported by FTIR spectra and elemental analysis. TGA/DTG spectra showed that the thermal stabilities of the guest anion in the both nanocomposites were markedly enhanced. A controlled-release study of the MPP ion from the MLHÀMPP/chitosan nanocomposite showed a slower release compared to MLHÀMPP nanocomposite with an initial rapid release and slow release thereafter. Meanwhile, the release behaviours of MPP ions from both nanocomposites were governed by pseudo-second order kinetics. This result highlights the potential of the nanocomposite as an encapsulated material for the controlled-release formulation of MPP anions.

Radionuclide-induced defect sites in iron-bearing minerals may have accelerated the emergence of life

“…These requirements can be realized with the double-layer hydroxides, which have a structure consisting of alternating positively charged hydroxide layers and hydrated anion layers. Double-layer hydroxides are a close relative of the more common layered double hydroxides, of which magnesium layer hydroxides are an example [31]. Specifically, the iron mixed-valent minerals, such as greenalite and fougèrite (i.e.…”