Combined Layer-by-Layer/Hydrothermal Synthesis of Fe3O4@MIL-100(Fe) for Ofloxacin Adsorption from Environmental Waters

: A simple not solvent and time consuming Fe3O4@MIL-100(Fe), synthesized in the presence of a small amount of magnetite (Fe3O4) nanoparticles (27.3 wt%), is here presented and discussed. Layer-by-layer alone (20 shell), and combined layer-by-layer (5 shell)/reflux or /hydrothermal synthetic procedures were compared. The last approach (Fe3O4@MIL-100_H sample) is suitable (i) to obtain rounded-shaped nanoparticles (200-400 nm diameter) of magnetite core and MIL-100(Fe) shell; (ii) to reduce the solvent and time consumption (the layer-by-layer procedure is applied only 5 times); (iii) to give the highest MIL-100(Fe) amount in the composite (72.7 vs. 18.5 wt% in the layer-by-layer alone); (iv) to obtain a high surface area of 3546 m2 g-1. The MIL-100(Fe) sample was also synthesized and both materials were tested for the absorption of Ofloxacin antibiotic (OFL). Langmuir model well describes OFL adsorption on Fe3O4@MIL-100_H, indicating an even higher adsorption capacity (218 ± 7 mg g-1) with respect to MIL-100 (123 ± 5 mg g-1). Chemisorption regulates the kinetic process on both the composite materials. Fe3O4@MIL-100_H performance was then verified for OFL removal at µg per liter in tap and river waters, and compared with MIL-100. Its relevant and higher adsorption efficiency and the magnetic behavior make it an excellent candidate for environmental depollution

Layered Double Hydroxides (LDHs): Versatile and Powerful Hosts for Different Applications

Layered double hydroxides are an emerging and intriguing class of materials having unique structural properties that allow their application in very different fields, such as catalysis, pollution control, agriculture, electronic, nanomedicine and drugs delivery. They are constituted by a sheets structure with formula [M2+1-x M3+x (OH)2](An-)x/n yH2O (M2+= Zn, Mg, Fe, Ni, Co..; M3+=Al, Ga, Fe…; An- = nitrates, carbonates, chloride). The exchange of these counterions with others inorganic/organic species, producing hybrid nanocomposites, makes these systems ideal candidates for many application. The goal is to find the right cationic ratio and the proper experimental conditions (pH, temperature, time, concentrations) to make the exchange process rapid and with high yield. A large number of synthetic processes for the nanocomposites production are theoretically disposable: coprecipitation, ionic exchange, reconstruction, hydrothermal or sol-gel synthesis. We will briefly describe the structural features of LDHs and the most widespread synthetic procedures

Intravenous Immunoglobulin and Mycophenolate Mofetil for Long-Standing Sensory Neuronopathy in Sjögren's Syndrome

Sensory neuronopathy is described in association with the Sjögren's syndrome (SS). We studied a 55-year-old woman with a 4-year history of progressive asymmetric numbness, distal tingling, and burning sensation in upper and lower limbs. In a few months, she developed ataxia with increased hypoanaesthesia. Electrodiagnostic tests revealed undetectable distal and proximal sensory nerve action potential in upper and lower limbs. Cervical spine magnetic resonance showed a signal hyperintensity of posterior columns. Previous treatment with high-dose glucocorticoids and azathioprine was ineffective. A combined treatment with intravenous immunoglobulin and mycophenolate mofetil was followed by a progressive and persistent improvement. This case documented the efficacy and the safety of the coadministration of intravenous immunoglobulin and mycophenolate mofetil in sensory neuronopathy associated with SS refractory to conventional immunosuppressive therapy