The influence of Si-modified TiO2 on the activity of Ag/TiO2 in CO oxidation

Nanocrystalline TiO₂ and Si-modified TiO₂ with Si/Ti ratios 0.01, 0.05, 0.1, and 0.3 were prepared by the solvothermal method and employed as the supports for Ag/TiO₂ catalysts for CO oxidation reaction. The incorporation of Si into the TiO₂ lattice in the form of Ti–O–Si as revealed by FT-IR results could inhibit the agglomeration of TiO₂ crystallites, resulting in an increase of both surface area and metal dispersion. However, there existed an optimum content of Si/Ti at ca. 0.05–0.1 which resulted in an improved catalytic activity of Ag/TiO₂ in CO oxidation. Based on the O₂-temperature program desorption (O₂-TPD) results, the catalysts with appropriate amounts of Si/Ti exhibited higher amount of O₂ adsorption and much lower desorption temperature. It is suggested that the presence of Ti–O–Si promoted the formation of active oxygen species and increased the mobility of lattice oxygen so that the catalytic activity was enhanced. There was no improvement in CO oxidation activity of the Ag/TiO₂ catalyst when the Si/Ti was further increased to 0.3 due probably to the formation of amorphous SiO₂ instead of the Ti–O–Si bond.     

Preparation of Lanthanum-Doped Pb(Zr,Ti)O3 Ceramics Sheets by Tape Casting

The physical and electrical properties of lanthanum doped Pb（Zr,Ti）O3 ceramic sheets （PLZT） which were prepared by tape casting method were carried out. Tape casting of lanthanum modified PZT was performed using commercial cellulose acetate binders and poly（ethylene glycol） plasticizers in ethanol solvent. Tapes from these slips were casted on a polymer substrate. The PLZT green tapes were stacked for 5 units and sintered in air at 1050℃ for 1 h with heating rate 5℃/min. SEM micrographs show that the tape is dense （90.26% of theoretical density） and rather uniform with grain size of approximately 1.1 9 m. The dielectric permittivity and loss tangent of PLZT ceramics as a function of temperature at 1 kHz suggest that the compounds exhibit a phase transition of diffuse type. The transition temperature （Tm ） and piezoelectric coefficient （ d33 ） were 110℃ and 117 pC/N, respectively.     

In Vitro and In Vivo Removal Efficacies of a Formulated Pumpkin Seed Oil Makeup Remover

Pumpkin seed oil is well known for its health benefits due to its high content of fatty acid constituents and tocopherols. The removal efficacy of pumpkin seed oil was assessed using UV–Vis spectroscopy. The oil was able to remove 79.92 ± 0.07%, 41.02 ± 0.25%, and 23.54 ± 0.19% of foundation and liquid and pen eyeliners. A stable makeup remover was formulated using 5–15% pumpkin seed oil. Addition of pumpkin seed oil significantly (P < 0.001) enhanced removal ability of the base remover. The remover containing 5% pumpkin seed oil was able to remove 89.27 ± 0.02%, 67.72 ± 0.08%, and 41.25 ± 0.07% of foundation, liquid, and pen eyeliners, respectively, while those of the remover containing 10% pumpkin seed oil were 78.24 ± 0.02%, 66.88 ± 0.05%, and 38.43 ± 0.05%, and those of the remover containing 15% pumpkin seed oil were 84.41 ± 0.01%, 69.79 ± 0.12%, and 41.88 ± 0.04%, respectively. On the other hand, removal efficiencies of the benchmark were 91.20 ± 0.03%, 73.46 ± 0.10%, and 54.00 ± 0.07%, respectively. The removers containing pumpkin seed oil did not cause skin irritation as monitored by a single closed-patch test in 10 female volunteers. The remover containing 5% pumpkin seed oil was further preference studied in 25 female volunteers in a comparison with the benchmark. The pumpkin seed oil remover gained a better overall preference over the benchmark (82.29 ± 4.17% and 80.20 ± 8.64%; P = 0.287). Of which, skin hydration of the developed bio-oil remover was significantly (P < 0.001) satisfied.     

Electrolytic admicellar polymerization of pyrrole on natural rubber/clay nanocomposites

Organic–inorganic composites consisting of natural rubber (NR), polypyrrole (PPy), and sodium montmorillonite (Na‐MMT) were synthesized via electrolytic admicellar polymerization. A constant potential of 9 volts was chosen for the synthesis. The PPy concentration was fixed at 100 mM, and the clay contents were varied from 1 to 7 parts per hundred of rubber (phr). The synthesized nanocomposites were characterized by Fourier transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), scanning electron microscopy, and transmission electron microscopy (TEM), together with thermal stability (TGA), mechanical properties, and electrical conductivity (σ_dc) studies. The FTIR spectra indicated the characteristic peaks of both PPy and MMT clay and also evidenced a slight interaction between the PPy chain and the clay layers, verifying the success of electrolytic admicellar polymerization. XRD and TEM results pointed out the good dispersion of clay platelets in the polymer matrix, suggesting an exfoliated structure. The morphology of the nanocomposites was greatly dependent on the amount of MMT clay, especially at a 7 phr loading. The initial modulus and tensile strength of the nanocomposites containing the 7 phr loading were about four and two times higher, compared with unfilled NR/PPy, respectively. Thermal stability studies revealed a slight improvement in the decomposition temperature for the PPy component by the clay layers, whereas the opposite trend was found for the NR component. More interestingly, the electrical conductivity of the admicelled rubber increased significantly (～ 19–32 times) with increasing clay contents from 1 to 7 phr, in comparison with unfilled NR/PPy. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Preparation and dielectric properties of barium iron niobate by molten-salt synthesis

In this work, barium iron niobate; BaFe_0.5Nb_0.5O₃ powder has been successfully synthesized by molten salt method. The power was characterized by a variety technique. Pure phase perovskite was obtained at relative low calcination temperature of <700 °C. The powder exhibits a fine grain with a relatively uniform particle size and microstructure. In addition, BaFe_0.5Nb_0.5O₃ ceramics were prepared and its dielectric properties were investigated. The result suggested that the ceramic prepared from molten-salt synthesis may be has a better properties than that of the ceramics synthesized by a conventional method.     

Ecological dyeing of silk fabric with lac dye by using padding techniques

This research focuses on silk fabrics exhibiting different colour values and fastness properties. The samples were prepared by dyeing with lac as a natural colourant. Two padding techniques were used in the process, namely, the pad-batch and pad-dry techniques, under different conditions. Aluminium potassium sulphate, ferrous sulphate, copper sulphate and stannous chloride were used as mordants. The effects of differing dye concentrations added to the silk fabrics using a pre- and post-mordant method were studied and recorded. The colour fastness to washing, light, rubbing, water and perspiration of the dyed samples was performed according to the present ISO standard. Silk fabric dyed without mordant showed a pink shade, while those samples mordanted with stannous chloride and aluminium potassium sulphate displayed noticeably brighter red coloured shades. With the additional use of copper sulphate, the colour shade produced was violet, while darker grey shades were obtained by adding ferrous sulphate mordant. The test results regarding fastness properties ranged from fair to very good, while wash fastness ranged from very poor to poor.     

Differential response of four human livers to modulation of phase II enzyme systems by the chemopreventive phytochemical phenethyl isothiocyanate

A principal mechanism of the chemopreventive activity of isothiocyanates is detoxification of the genotoxic metabolites of chemical carcinogens through up‐regulation of enzymes such as quinone reductase and the glutathione‐S‐transferases. In this study we report, for the first time, the potential of the aromatic isothiocyanate, phenethyl isothiocyanate (PEITC) to modulate these enzymes in human liver from four donors, in comparison with rat liver. Precision‐cut human and rat liver slices were incubated with PEITC at concentrations that can be achieved in plasma following dietary intake. Glutathione‐S‐transferase activity increased in rat slices whereas in human slices activity rose only in three of the four donors. At the protein level, a marked rise in GSTα was seen in one of the human donors whereas much less pronounced elevation was noted in the other three. Quinone reductase activity doubled in rat liver slices incubated with PEITC, and was accompanied by an increase in protein expression. Only in one of the human donors was activity and expression of quinone reductase elevated. These studies illustrate that there are very pronounced differences in the response of human liver to PEITC, indicating that the chemopreventive effect of isothiocyanates may not be manifested in all individuals.     

Repeated oral administration modulates the pharmacokinetic behavior of the chemopreventive agent phenethyl isothiocyanate in rats

The principal objective of this study was to evaluate whether repeated oral administration influences the pharmacokinetic behavior of the chemopreventive agent phenethyl isothiocyanate (PEITC) in rat. Animals were treated orally with 0.5, 1.0 and 5.0 mg/kg of the isothiocyanate for 4 days, and plasma levels at various times post‐administration were determined by LC/MS after the first and last day. To determine absolute bioavailability, a group of animals was treated with a single (0.5 mg/kg) intravenous dose of PEITC. Following single oral dose administration, PEITC was rapidly absorbed, peak plasma concentrations being attained within the hour, and achieved an absolute bioavailability of 77%, but displayed dose‐dependent pharmacokinetics, with bioavailability decreasing and clearance increasing moderately with dose; C_max values did not rise proportionately to the dose and volume of distribution increased. At the higher doses of 1.0 and 5.0 mg/kg, repeated administration led to higher PEITC plasma C_max concentrations and decreased plasma clearance of the isothiocyanate leading to enhanced bioavailability.     

Morphology development and stability of polypropylene/organoclay nanocomposites

A series of polypropylene (PP)/organoclay nanocomposites with varied concentrations of clay, from 1 to 7 wt%, was successfully prepared via melt intercalation using a PP functionalized with maleic anhydride as compatibilizer. The morphology/property relationships of the nanocomposites were investigated by XRD, TGA and DSC analyses. Two distinct groups of composites, from a quasi-exfoliated to an intercalated/flocculated morphology, were identified. In particular, intercalated/flocculated morphologies were obtained for those composites with an organoclay concentration beyond the threshold (3 wt%), as evidenced by XRD analysis and confirmed by the increase of the glass transition temperature. This last effect was related to the confinement of polymer chains between the silicate layers, generating a reduction of the chain mobility. The variable increase of the thermal stability of the nanocomposites was also likely related to the different degree of exfoliation/intercalation of the samples. The toluene extraction of composites was used as a powerful methodology to distinguish between polymer phases differently interacting with the inorganic surface: composites having a semi-exfoliated structure were split into two fractions having a similar morphology. For those samples having the higher organoclay concentration and intercalated morphology, a toluene-residue fraction was obtained containing almost all the clay present in the pristine composite. Furthermore, in this case the morphological analysis of the residue fraction evidenced a collapse of the inorganic structure compared to that of the unextracted composite. A careful characterization of both soluble and residue fractions is reported and the results are discussed considering the interactions at the interface between the functionalized PP chains and silicate layers and their effects on the organoclay dispersion degree and stability.