Search results for "Salt"
showing 10 items of 1157 documents
Experimental investigation on tensile and shear bond behaviour of Basalt-FRCM composites for strengthening calcarenite masonry elements
2023
The use of Fabric Reinforced Cementitious Matrix (FRCM) composites for structural retrofit has seen an increased interest among the scientific community, during the last decade. Various studies have revealed their effectiveness as external retrofitting technique of masonry elements, offering numerous advantages respect to the well know Fibre Reinforced Polymer (FRP) in terms of compatibility with masonry support, reversibility of intervention and sustainability. Despite the growing use, the characterization of FRCM mechanical behaviour is still an open issue, due to numerous uncertainties involved in test set-up adopted and fibre-mortar combination. The proposed experimental study aims to i…
Ion Pair Recognition of Quaternary Ammonium and Iminium Salts by Uranyl-Salophen Compounds in Solution and in the Solid State
2007
Efficient ditopic receptors for quaternary ammonium and iminium salts have been obtained upon functionalization of the uranyl-salophen unit with conformationally flexible side arms bearing phenyl or beta-naphthyl substituents. Binding affinities in chloroform solution have been measured for a large number of quaternary salts comprising tetramethylammonium (TMA), tetrabutylammonium (TBA), acetylcholine (ACh), N-methylpyridinium (NMP), and N-methylisoquinolinium (NmiQ) cations. Recognition of the anion partner is ensured by coordination to the hard Lewis acidic uranyl center, whereas cation-pi/CH-pi interactions of the quaternary ions are established with the aromatic pendants. The role of th…
2-Hydroxyoleic Acid Induces ER Stress and Autophagy in Various Human Glioma Cell Lines
2012
Background: 2-Hydroxyoleic acid is a synthetic fatty acid with potent anti-cancer activity which does not induce undesired side effects. However, the molecular and cellular mechanisms by which this compound selectively kills human glioma cancer cells without killing normal cells is not fully understood. The present study was designed to determine the molecular bases underlying the potency against 1321N1, SF-767 and U118 human glioma cell lines growth without affecting non cancer MRC-5 cells. Methodology/Principal Findings: The cellular levels of endoplasmic reticulum (ER) stress, unfolded protein response (UPR) and autophagy markers were determined by quantitative RT-PCR and immunoblotting …
Study on the thermotropic properties of highly fluorinated 1,2,4-oxadiazolylpyridinium salts and their perspective applications as ionic liquid cryst…
2007
A new series of fluorinated salts, iodides and trifluoromethanesulfonates, was synthesized from perfluoroalkylated 1,2,4-oxadiazolylpyridines. Their thermotropic properties were investigated by combined temperature resolved small angle and wide angle X-ray scattering, differential scanning calorimetry and polarised optical microscopy. The UV–visible and photoluminescence properties were studied for all compounds. The results showed for two compounds the existence of an enantiotropic mesomorphic smectic liquid crystal phase. All iodides showed thermochromism phenomena suggesting prospective applications in optoelectronics.
Development and characterization of co-loaded curcumin/triazole-halloysite systems and evaluation of their potential anticancer activity.
2014
Abstract Positively charged halloysite nanotubes functionalized with triazolium salts (f-HNT) were employed as a carrier for curcumin molecules delivery. The synthesis of these f-HNT new materials is described. Their interaction with curcumin was evaluated by means dynamic light scattering (DLS) and UV–vis spectroscopy in comparison with pristine unmodified HNT (p-HNT). The curcumin load into HNT was estimated by thermogravimetric analysis (TGA) measurements, while the morphology was investigated by scanning electron microscopy (SEM) techniques. Release of curcumin from f-HNT, at three different pH values, by means of UV–vis spectroscopy was also studied. Furthermore, different cancer cell …
Efficient Conversion of Carbon Dioxide by Imidazolium-Based Cross-Linked Nanostructures Containing Polyhedral Oligomeric Silsesquioxane (POSS) Buildi…
2019
Polyhedral oligomeric silsesquioxanes (POSS) have been employed as molecular building blocks for the synthesis of imidazolium cross-linked networks, to be used as heterogeneous catalysts for the conversion of carbon dioxide into cyclic carbonates. Two hybrid materials with different nucleophilic species (bromide and iodide) have been prepared and characterized by means of elemental analysis, 13C and 29Si solid-state NMR spectroscopy, thermogravimetric analysis and IR spectroscopy. The solids were tested as the sole catalyst under metal- and solvent-free reaction conditions showing full selectivity toward the formation of cyclic carbonates. High turnover number (TON) and productivity values,…
Palladium supported on Halloysite-triazolium salts as catalyst for ligand free Suzuki cross-coupling in water under microwave irradiation
2015
Abstract Environmental friendly halloysite-dicationic triazolium salts (second generation) obtained by subsequent click reactions of a diyne derivative in the presence of 2-azidopropyl-modified halloysite nanotubes, were used as supports for palladium catalyst. Thanks to the high triazolium loading (25%) these materials were able to support higher amount of the metal than that on the monocationic derivative (first generation). Such materials were characterized by thermogravimetric analysis, FT-IR spectroscopy and SEM investigations. The new catalytic system was employed in the ligand free Suzuki cross-coupling under microwave irradiation. A set of solvent, time and% loading of palladium was…
The anion impact on the self-assembly of naphthalene diimide diimidazolium salts
2017
Naphthalene diimide diimidazolium salts differing in the anion nature were synthesized and their properties as well as their self-assembly behaviour were investigated. In particular, we took into consideration the N,N′-bis-(1-octyl-3-propylimidazolium)-naphthalene diimide cations and anions differing in size, shape and coordination abilities like [I−], [BF4−] and [NTf2−]. After determination of thermal behaviour, using differential scanning calorimetry and thermal gravimetric analysis, the electrochemical stability and redox properties were assessed using cyclic voltammetry. The self-assembly behaviour of the salts was investigated using concentration and temperature-dependent spectroscopic…
Experimental assessment of reverse electrodialysis in closed loop configuration fed by NH4HCO3-water solutions
2018
Closed loop reverse electrodialysis is a novel technology for converting low-temperature waste heat into electric energy. This innovative heat engine consists of two units: (i) a reverse electrodialysis unit where power is produced exploiting the concentration difference between a diluted and a concentrated salt solution and (ii) a thermally driven regeneration unit where low-grade waste heat is used to re-establish the original salinity gradient between the two salt solutions. Among all the possible salt solutions suitable as working fluid in such application, Thermolytic salts solutions, in particular Ammonium bicarbonate solutions, may be promising thanks to their characteristic thermall…
DFT study on the cycloreversion of thietane radical cations.
2011
The molecular mechanism of the cycloreversion (CR) of thietane radical cations has been analyzed in detail at the UB3LYP/6-31G* level of theory. Results have shown that the process takes place via a stepwise mechanism leading to alkenes and thiobenzophenone; alternatively, formal [4 + 2] cycloadducts are obtained. Thus, the CR of radical cations 1a, b(center dot+) is initiated by C2-C3 bond breaking, giving common intermediates INa,b. At this stage, two reaction pathways are feasible involving ion molecule complexes IMCa,b (i) or radical cations 4a,b(center dot+) (ii). Calculations support that 1a(center dot+) follows reaction pathway (leading to the formal [4 + 2] cycloadducts 5a). By cont…