Catalytic Activity of Ag-Co-MCM-41 for Liquid-Phase Selective Oxidation of Styrene to Benzaldehyde.

A series of Ag-Co-MCM-41 with different metal loadings have been synthesized through the hydrothermal method. All the prepared catalysts were characterized by N2 adsorption-desorption, X-ray diffraction analysis, transmission electron microscopy. The results revealed that the structure of MCM-41 was well preserved and Ag and Co have been introduced successfully into the mesoporous channels of MCM-41. The liquid-phase catalytic oxidation of styrene on these catalysts was investigated using H2O2 as an oxidizing agent and acetone as a solvent in thermostatic water bath. The influence of metal loading, the catalyst dose, temperature, time and styrene/oxidant molar ratio on the conversion of styrene and yield and selectivity of benzaldehyde was investigated. Also, the reusability of the catalysts was evaluated.

Drug Release Behavior of Doxorubicin Hydrochloride-Loaded Poly(L-Lactic Acid)/Hydroxyapatite/Gelatin by Surface Modification of Hydroxyapatite.

The doxorubicin hydrochloride (DOX)-loaded poly(L-lactic acid)/hydroxyapatite/gelatin (PLLA/a-HA/gelatin) particle was prepared by emulsion/solvent evaporation method using CH2Cl2 as a solvent. HA nanoparticles were prepared via a facile chemical precipitate method and HA nanoparticles were functionalized by adding aminopropyltriethoxysilane (APTS) under microwave radiation. The physical and chemical properties of HA and modified HA were characterized by XRD, TEM, FT-IR, and XPS. Furthermore, the release of DOX from PLLA/a-HA/gelatin was also estimated. Results indicated that HA was successfully functionalized via APTS and functionalized HA has primary amino groups on its surface which improved the surface chemical compatibility between HA and PLLA matrix. The prepared PLLA/a-HA/gelatin was considered as a drug release carrier to study sustained release behavior of doxorubicin hydrochloride (DOX). The PLLA/a-HA/gelatin can effectively prolong the release time of DOX and exhibits a stable and sustainable drug release which indicates that the PLLA/a-HA/gelatin nanocomposite material could serve as a potential carrier for novel drug release system.

Removal of Cu(II) Ions from Aqueous Solution Using Fe/La-CTAB-Graphene Oxide Nanocomposite as Efficient Adsorbent.

We report an approach for synthesis of Fe/La-CTAB-graphene oxide (GO) nanocomposite with coprecipitation method prepared from natural graphite. The nanocomposite was characterized by XRD, FT-IR, SEM and TEM, and was applied to remove copper ions in aqueous system. Also, the effect of various factors such as contact time, temperature, initial concentration of Cu(II) ions, and solution pH on Cu(II) ions adsorption over Fe/La-CTAB-GO nanocomposite was investigated. The results reveal that removal percentage of Cu(II) ions is over 91% (pH = 6.0) within 90 min, along with the initial concentration of Cu(II) ions of 10 mg/L and the dose of 15 mg. The adsorption of Cu(II) ions over Fe/La-CTAB-GO nanocomposite fitted well to Langmuir isotherm model (R2 = 0.99855) and followed the pseudo-second-order kinetic (R2 = 0.99974). Thermodynamic parameters declare that the adsorption process is endothermic and spontaneous. Results of this work suggest that Fe/La-CTAB-GO nanocomposite can be a promising adsorbent for the removal of copper ions in aqueous solutions.

Highly Efficient Visible-Light-Driven Graphene-CdS Nanocomposite Photocatalysts.

Graphene-CdS nanocomposites with different CdS contents were synthesized via a solvothermal route. Compared with pure CdS, graphene-CdS composites exhibited higher efficiency in photodegradation of methylene blue (MB) under visible light irradiation. TEM observations demonstrated that a homogeneous distribution of CdS nanoparticles on the graphene nanosheets was formed, while the CdS nanoparticles on graphene-CdS composite (1 g/7.5 mmol) distributed best among graphene-CdS composites. The results show that the graphene-CdS composite (1 g/7.5 mmol) has the highest efficiency and well stability. It demonstrated the mechanism of photodegration was that ˙OH radical generated by graphene-CdS composite plays a vital role by adding dimethyl sulfoxide (DMSO).