The development of fluorescent materials that can act as sensors for the determination of metal ions in biological fluids is important since they show, among others, high sensitivity and specificity. However, most of the molecules that are used for these purposes possess a very low solubility in aqueous media, and, thus, it is necessary to adopt some derivation strategies. Clay minerals, for example, hectorite, as natural materials, are biocompatible and available in large amounts at a very low cost that have been extensively used as carrier systems for the delivery of different hydrophobic species.
View Article and Find Full Text PDFTo date, the need for biomaterials capable of improving the treatment of chronic skin wounds remains a clinical challenge. The aim of the present work is to formulate and characterize chitosan (Cs)/hydrolyzed collagen (HC) films as potential biomaterials with improved mechanical and hydration performances compared to single component formulations. Films were made by the solvent casting method, with or without glycerin and/or PEG1500 as plasticizers, resulting in a total of eight formulations.
View Article and Find Full Text PDFAlkaline hydrothermal vents have become a candidate setting for the origins of life on Earth and beyond. This is due to several key features including the presence of gradients of temperature, redox potential, pH, the availability of inorganic minerals, and the existence of a network of inorganic pore spaces that could have served as primitive compartments. Chemical gardens have long been used as experimental proxies for hydrothermal vents.
View Article and Find Full Text PDFSulfathiazole is an antimicrobial belonging to the family of sulfonamides, which were the first antibiotics to be discovered. Sulfathiazole is generally administered orally, and its main disadvantage is that it has low aqueous solubility, requiring high doses for its administration. This fact has led to side effects and the generation of bacterial resistance to the drug over time.
View Article and Find Full Text PDFThe aim of this study was to investigate the biomimetic precipitation processes that follow the chemical-garden reaction of brines of CaCl and sulfate salts with silicate in alkaline conditions under a Mars-type CO-rich atmosphere. We characterize the precipitates with environmental scanning electron microscope micrography, micro-Raman spectroscopy, and X-ray diffractometry. Our analysis results indicate that self-assembled carbonate structures formed with calcium chloride can have vesicular and filamentary features.
View Article and Find Full Text PDFThe adsorption of retinol, niacinamide and glycolic acid active ingredients on the internal surface of halloysite in an aqueous environment was explored at the molecular level by means of calculations based on quantum mechanics and force fields from empirical interatomic potentials. These active ingredients are stably adsorbed on the internal surface of halloysite forming hydrogen bonds between the hydrogen, oxygen and nitrogen atoms with the hydroxyl groups of the inner surface of the halloysite. In addition, electrostatic interaction between these active ingredients with the water molecules was observed.
View Article and Find Full Text PDFMuscovite (Ms) and phlogopite (Phl) belong to the 2:1 dioctahedral and trioctahedral layer silicates, respectively, and are the end members of Ms-Phl series minerals. This series was studied in the 2M polytype and modeled by the substitution of three Mg cations in the Phl octahedral sites by two Al and one vacancy, increasing the substitution up to reach the Ms. The series was computationally examined at DFT level as a function of pressure to 9 GPa.
View Article and Find Full Text PDFIn this study, stable hybrid materials (Mt-Fe(III)Phen), made by the μ-oxo Fe(III)-phenanthroline complex [(OH)(Phen)FeOFe(Phen)(OH)] (Fe(III)Phen) intercalated in different amounts into montmorillonite (Mt), were used as a trap for immobilizing gaseous benzene and naphthalene and their mono chloro-derivatives at 25 and 50 °C. The entrapping process was studied through elemental analysis, magic angle spinning NMR spectroscopy, thermal analysis, and evolved gas mass spectrometry. Naphthalene and 1-chloronaphthalene were found to be immobilized in large amount at both temperatures.
View Article and Find Full Text PDFThe μ-oxo Fe(III)-phenanthroline complex [(OH)(Phen)FeOFe(Phen) (OH)] intercalated in montmorillonite provides a stable hybrid material. In this study, the ability and efficiency of this material to immobilize thiols in gas phase, acting as a trap at the solid-gas interface, were investigated. Aliphatic thiols containing both hydrophilic and hydrophobic end groups were chosen to test the selectivity of this gas trap.
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