Comparative and Efficient Ammonia Gas Sensing Study with Self-assembly-Synthesized Metal Oxide-SiC Fiber-Based Mesoporous SiO2 Composites.

Self-assembled-assisted ternary nanocomposite In2O3-SiC, CuO2-SiC, and MnO2-SiC semiconductors were mixed with SiO2 to enable gas sensing using cyclic voltammetry. The results of TEM (transm In2O3-SiC-SiO2 ion electron microscopy), X-ray diffraction spectroscopy, and Raman spectra analysis affirm the closeness of few layers between SiO2 and SiC in In2O3-SiC, MnO2-SiC, and CuO2-SiC. Among the electrochemical impedance spectra curves of the nanocomposites, none of the samples had a semicircle profile, which indicates the existence of a higher charge-transfer resistivity behavior between the electrolyte and the sample electrode with charge carrier and transport effects, which is related to the well-developed porous structure of synthesized composites. CuO2-SiC-SiO2 and MnO2-SiC-SiO2 showed high resistivity and a quite significant response for NH3 gas at room temperature. While there was a response for NH3 gas for In2O3-SiC-SiO2, the sensor showed a low response for the gas. From the sensing test, correspondences between the chemical structure of the sensor and the molecular structure of the gases have been found. The surface reactions between the sensor surface and the gas with a pore structure, along with the electron receiver/donor phase are observed from the results of gas sensor tests, and all factors are determining the precise state. Finally, the adsorption of NH3 molecules and the alteration of the electronic resistance of In2O3-SiC-SiO2, MnO2-SiC-SiO2, and CuO2-SiC-SiO2 were presented that include various thicknesses of charge to represent which are achieved by the connection with the substrates and the particles.

Instantaneous integration of magnetite nanoparticles on graphene oxide assisted by ultrasound for efficient heavy metal ion retrieval.

We fabricated a magnetite nanoparticle-graphene oxide (GO) hybrid via a non-chemical and one-step process assisted by ultrasound in an aqueous solution where the nanoparticle attached to the hydrophobic region on graphite oxide (multi-layered GO) which, at the same time, was exfoliated. Unlike chemical methods such as precipitation, oxygen-containing functional groups on GO have not been consumed or reduced during the hybridization, leading that this hybrid exhibited good water solubility and high adsorption capacity for heavy metal ions such as Pb(II) and Au(III). After the adsorption, the hybrid was instantly collected using a magnet. This method can be useful for hybridizing various nanoparticles with GO.

Long-term stability of CdSe/CdZnS quantum dot encapsulated in a multi-lamellar microcapsule.

We developed a novel and easy encapsulation method for quantum dots (QDs) using a partially oxidized semi-crystalline polymeric material which forms a micron-sized granule with a multi-lamellar structure from a dilute solution. The QDs were highly dispersed in the granule in such a way that they were adsorbed on the lamella with ∼12 nm spacing followed by lamellar stacking. The QDs were heavily loaded into the granule to 16.7 wt% without aggregation, a process which took only a few minutes. We found that the quantum yield of the QDs was not degraded after the encapsulation. The encapsulated QD-silicone composite exhibited excellent long-term photo- and thermal stability with its initial photoluminescence intensity maintained after blue LED light radiation for 67 days and storage at 85 °C and 85% relative humidity for 119 days.

Protective effect of extracts of Perilla frutescens treated with sucrose on tert-butyl hydroperoxide-induced oxidative hepatotoxicity in vitro and in vivo.

Perilla frutescens leaves are often used in East Asian gourmet food. In this study, we investigated the hepatoprotective effects of P. frutescens leaves grown in different concentrations of sucrose (0, 115, 175 and 235 mM sucrose) leading to four samples of perilla leaf extracts (PLEs). Based on caffeic acid level and antioxidant activities, further experiments were conducted using perilla leaf extracts treated with 6% sucrose compared with non-treated perilla leaf extracts as a control. Oral intubation with non-treated perilla leaf extracts or perilla leaf extracts treated with 6% sucrose (1000 mg/kg b.w. rat) for 5 days was conducted before treatment with a single dose of tert-butyl hydroperoxide (0.5 mmol/kg b.w., i.p.) led to a significant reduction of hepatic toxicity in the perilla leaf extracts treated with 6% sucrose. We demonstrated that P. frutescens with higher contents of caffeic acid was produced, and that sucrose could play a role in the induction of this secondary metabolite. Sucrose-treated perilla leaves, which had better antioxidant activities than untreated leaves, can be used as a potential dietary source.