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Abstract: In this paper, we have prepared the fluorescent silica nanoparticles (FSNPs) covalently doped with rhodamine B (RB) dye molecules via 3-aminopropyltriethoxysilane (APTES) in reverse microemulsion method. Then by the cohydrolysis and polymerization of tetraethoxysilane (TEOS) and APTES, the surface of the FSNPs formed another thin silica shell with the functionalized amino groups. The resulting nanoparticles were characterized by infrared (IR) spectrum, transmission electron microscopy (TEM), and spectrofluorimetry. TEM showed that the particles with diameters in the range of 70–500nm were obtained, with core and shell sizes controlled by varying component content. At the same time, the effect of RB content on the fluorescent properties of the FSNPs was studied, and the results indicated that the fluorescence intensity of the FSNPs could be precisely tuned by varying the doping amount of RB dyes. Finally, the dye leakage was also tested, displaying that RB molecules would not leak out from the silica nanoparticles after dispersing in the aqueous solution. [Copyright &y& Elsevier]

• TiO 2 nanosheets supported Ru nanoparticles form strong interfacial Ru O Ti structure. • Ru/TiO 2 reached the highest TOF of 19,045 h−1for levulinic acid (LA) hydrogenation. • 99.1% yield of γ-valerolactone (GVL) was achieved over Ru/TiO 2. • DFT calculations clearly elucidate reaction mechanism of LA hydrogenation to GVL. • Ru/TiO 2 interface tunes rate-determining step from LA hydrogenation to cyclization. Highly efficient synthesis of valuable γ-valerolactone (GVL) by levulinic acid (LA) hydrogenation is still a challenge for Ru-based catalysts under mild condition. In this work, we have reported that ultrathin TiO 2 nanosheets supported Ru nanoparticles showed extraordinarily high catalytic activity, GVL yield (99.1%) and reusability owing to the formation of Ru O Ti interfacial structure. The turnover frequency (TOF) reached as high as 19,045 h−1 at 100 °C, much higher than those of Ru/SiO 2 , Ru/GO, Ru/MoS 2 , and commercial Ru/C. DFT calculation elucidates that the dominant reaction pathway of LA hydrogenation to GVL is preferentially hydrogenated to CH 3 CHOCH 2 CH 2 COOH*, followed by cyclization to CH 3 (OH)C 4 OH 4 OH* (GVL − OH) and final dehydroxylation, irrespective of surface structure. Compared to Ru (0 0 2) facet, Ru/TiO 2 interfacial structure changes the rate-determining step from initial hydrogenation to cyclization, which greatly declines the activation barrier from 0.81 eV to 0.48 eV. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents a feasible protocol for the preparation of a novel versatile nanocomposite possessing superparamagnetism via a layer-by-layer method. We combined (3-aminopropyl)triethoxysilane-coated magnetic Fe3O4 nanoparticles (APTES-MNPs) with β-cyclodextrin (β-CD). The following unusual features were integrated in a single nano-system: (a) the silane coating outside the magnetic Fe3O4 cores derived from the hydrolysis of APTES acted as a coupling agent and provided amino group (–NH2) for linking the CD molecule; (b) the outermost CD moieties can function as inclusion sites and specific containers for drugs and biomolecules; (c) the innermost magnetic cores were able to sense and respond to an externally applied magnetic field and their behaviors in vivo or in vitro can be artificially manipulated and navigated. The obtained nanocomposite turned out to be superparamagnetic with a relatively high saturation magnetization value of 69emug−1, which implies potentially promising applications in magnetic drug delivery technology and bioseparation. [Copyright &y& Elsevier]

Abstract: Nickel nanoparticle-doped pitch (NNDP) was prepared using the detonation of a Ni-containing explosive during the thermal polycondensation of ethylene bottom oil. The NNDP melt was centrifugally electrospun into fibers and formed the Ni nanoparticle-doped carbon fibers (NNDCFs) with diameters of 2–50μm after heat treatment. [Copyright &y& Elsevier]