Intercalation of calcein into layered silicate magadiite and their optical properties

Progress in Development of Magadiite to Produce Multifunctional Lamellar Materials

The attractive properties of magadiite, a lamellar and crystalline material, could give rise to new industrial processes due to its unique and modulating intrinsic properties. In this context, the high degree of expansion of its lamellae, a key factor for its potential use in several areas of scientific research, has attracted the attention of several researchers. The aim of this review is to provide a historical overview of the hypothetical models developed to explain the magadiite crystalline structure. Furthermore, different synthesis strategies for the preparation of magadiites as sodic, protonic, and hybrid (inorganic-inorganic and inorganic-organic) materials are discussed along with several routes for obtaining modified magadiites. Also, the use of magadiite in catalytic reactions, notably in ethanol dehydration and fructose conversion reactions, is a growing area of research. Other potential applications include the adsorption and absorption of environmental pollutants (e.g., phenol and methylene blue in wastewater), use as a photocatalyst in the oxidation of toluene, and use in medicine (e.g., as a drug delivery or antibacterial/antifungal agent). This highlights the many opportunities for the development of new synthesis methods to obtain multifunctional materials in the search for new applications.

Highly efficient triazolone/metal ion/polydopamine/MCM-41 sustained release system with pH sensitivity for pesticide delivery

MCM-41 was prepared through the sol-gel method and encapsulated by polydopamine (PDA) before being coordinated with metal ions to form a highly efficient sustained release system (M-PDA-MCM-41) for triazolone delivery. The characterization results confirmed the existence of the coordination bond between the PDA layer and triazolone through the bridge effect from metal ions, which enhanced the interaction between PDA-MCM-41 and triazolone. The adsorption capacity of Fe-PDA-MCM-41 increased up to 173 mg g-1, which was 160% more than that of MCM-41. The sustained release performance of M-PDA-MCM-41 in different pH values was investigated. Under the conditions of pH ≤7, the release speed of triazolone increased with pH decreasing, whereas its release speed in the weak base condition was slower than in the neutral condition. Therefore, the as-synthesized system showed significant pH-sensitivity in the sustained release process, indicating that the sustained release system can be well stored in the neutral or basic environment and activated in the acid environment. Their sustained release curves described by the Korsmeyer-Peppas equation at pH 7 showed the same behaviour, indicating that PDA decoration or metal ion coordination only increases the steric hindrance and the interaction between carrier and triazolone instead of changing the original structure of the pure MCM material in accordance with X-ray diffraction and Brunauer-Emmett-Teller analysis results.