One-Pot Environmentally Friendly Synthesis of Nanomaterials Based on Phytate-Coated Fe3O4 Nanoparticles for Efficient Removal of the Radioactive Metal Ions 90Sr, 90Y and (UO2)2+ from Water.

We report the fast (three minutes) synthesis of green nanoparticles based on nanoparticles coated with the natural organic receptor phytate for the recognition and capture of 90Sr, 90Y, and (UO2)2+. The new material shows excellent retention for (UO2)2+, 97%; these values were 73% and 100% for 90Sr and 90Y, respectively. Recovery of the three radioactive metal ions occurs through a non-competitive process. The new hybrid material is harmless, easy to prepare, and immobilizes these radioactive contaminants in water with great efficiency.

Effective Elimination and Biodegradation of Polycyclic Aromatic Hydrocarbons from Seawater through the Formation of Magnetic Microfibres.

Supramolecular aggregates formed between polycyclic aromatic hydrocarbons and either naphthalene or perylene-derived diimides have been anchored in magnetite magnetic nanoparticles. The high affinity and stability of these aggregates allow them to capture and confine these extremely carcinogenic contaminants in a reduced space. In some cases, the high cohesion of these aggregates leads to the formation of magnetic microfibres of several microns in length, which can be isolated from the solution by the direct action of a magnet. Here we show a practical application of bioremediation aimed at the environmental decontamination of naphthalene, a very profuse contaminant, based on the uptake, sequestration, and acceleration of the biodegradation of the formed supramolecular aggregate, by the direct action of a bacterium of the lineage Roseobacter (biocompatible with nanostructured receptors and very widespread in marine environments) without providing more toxicity to the environment.

Influence of the aromatic surface on the capacity of adsorption of VOCs by magnetite supported organic-inorganic hybrids.

It has been recently evidenced that hybrid magnetic nanomaterials based on perylene diimide (PDI) dopamine and iron oxide nanoparticles are useful for the adsorption and determination of volatile organic compounds (VOCs). However, NDI compounds are expensive and difficult to handle compared to smaller size diimides. Therefore, in this manuscript a combined experimental and theoretical investigation is reported including the analysis of the effect of changing the aromatic surface on the ability of these magnetite supported organic-inorganic hybrid nanoparticles (NPs) to adsorb several aromatic and non-aromatic VOCs. In particular, two new hybrid Fe3O4NPs are synthesized and characterized where the size of organic PDI dopamine linker is progressively reduced to naphthalene diimide (NDI) and pyromellitic diimide (PMDI). These materials were utilized to fill two sorbent tubes in series. Thermal desorption (TD) combined with capillary gas chromatography (GC)/flame detector (FID) was used to analyze both front and back tubes. Adsorption values (defined as % VOCs found in the front tube) were determined for a series of VOCs. The binding energies (DFT-D3 calculations) of VOC-Fe3O4NP complexes were also computed to correlate the electron-accepting ability of the arylene diimide (PDI, NDI or PMDI) with the adsorption capacity of the different tubes. The prepared hybrids can be easily separated magnetically and showed great reusability.

Removal of Au3+ and Ag+ from aqueous media with magnetic nanoparticles functionalized with squaramide derivatives.

New magnetic hybrid nanoparticles of Fe3O4 coated with organosulfur-squaramide compounds are prepared. The modified-nanoparticles show a good coordination for Ag+ and Hg2+ cations in water, and present a high affinity for Au3+ ions. The behaviour of the squaramide-coated nanoparticles differs significantly from that previously reported for nanoparticles used as Au3+ scavengers. In the presence of organosulfur-squaramide, the Au3+ salt is reduced to gold nanoparticles that are deposited upon Fe3O4 nanoparticles. For the first time, the coordination capacity of the carbonyl squaramide groups with the gold cation, based on purely electrostatic cation-dipole interactions, is proved.

A Very Highly Efficient Magnetic Nanomaterial for the Removal of PAHs from Aqueous Media.

Two new hybrid magnetic recyclable nanomaterials are developed. These new materials are based on bisimide perylene dopamine or bisimide perylene 3-aminopropyltriethoxysilane and iron oxide nanoparticles. One of them, the bisimide perylene dopamine, has proven to be very efficient in the removal, by magneto filtration, of 15 carcinogenic polycyclic aromatic compounds (PAHs), especially naphthalene, acenaphthene, anthracene, phenanthrene, and fluorene. These compounds are known to be common contaminants of drinking and underground water. This nanomaterial presents a high dispersivity and stability in an aqueous media, and it is capable of forming supramolecular fluorescent magnetic nanofibers with benzo-alpha-pyrene or benzo[k]fluoranthene, BKF. This strong association is due to hydrophobic forces and the π-π interaction, between the bisimide perylene motif and the polycyclic aromatic compounds. The resilience of this material is tested in different media. No good results are obtained in ethanol, acetone, or acetonitrile, but an 85% recovery is achieved using toluene or hexane. Once washed, nanoparticles are shown to retain their ability to continue capturing PAHs.