In this article we carried out a detailed solid-state NMR investigation about the incorporation of model drug indomethacin into several different metal-organic porous matrices of the MIL-101 type. The investigated systems represented model drug-delivery systems. The MIL-101 matrices differed one from another in the metal centres building the vertices of their porous frameworks (Al, Fe, Cr) and in the presence or absence of functional groups on the organic linkers that connected the above mentioned metal-oxo vertices into the metal-organic frameworks. We showed that NMR spectroscopy can detect interactions between the drug molecules and the frameworks and thus provide information that is very important for the uderstanding of the drug release. We found out that the investigated metal-organic carriers are not as convenient as mesoporous silicate carriers as their system of pores are less permeable for the drug molecules. Furthermore, the MIL-101 frameworks contained also more hydrogen-bond donor sites, which attract and bond solvent molecules and make removal of these molecules from the pores more difficult.
COBISS.SI-ID: 5447706
In this article two new potential heat-storage materials were prepared and inspected. The first material was a composite of a disordered mesoporous material and calcium chloride and the second was a composite of an ordered mesoporous material and calcium chloride. Both materials exhibited good hydrothermal stability; after 20 cycles of water sorption/desorption no leakage of the salt hydrate from the composites was detected. It was shown that the introduction of calcium chloride enhances water sorption capacity of the two materials. The material with the ordered mesoporous matrix showed higher capacity with maximal water uptake of 0.88 g/g.
COBISS.SI-ID: 5457434
In this article nanostructural, morphological and textural properties of perlites were explored by spectroscopic and microscopic techniques. Perlites are natural igneous aluminosilicate materials, characterized by low density, extensive surface area, increased porosity and remarkable water and air holding capacity. MAS NMR results, when combined with data from FTIR spectroscopy and microscopic observation, yielded information on the aluminosilicate backbone leading to a better understanding of the behavior of perlites under expansion and dehydration processes. SEM was applied to inspect the morphology and dynamics of perlites during expansion and to clarify their interactions with the escaping water.
COBISS.SI-ID: 5576730