RESUMO
Owing to their excellent characteristics, Pickering emulsions have been widely used in the development and the application of new carriers for embedding and for delivering active compounds. In this study, ß-carotene was successfully encapsulated in a Pickering emulsion stabilized using Desmodium intortum protein isolate (DIPI). The results showed that the encapsulation efficiencies of ß-carotene in the control group Tween 20 emulsion (TE) and the DIPI Pickering emulsion (DIPIPE) were 46.7 ± 2.5% and 97.3 ± 0.8%, respectively. After storage for 30 days at 25 °C and 37 °C in a dark environment, approximately 79.4% and 72.1% of ß-carotene in DIPIPE were retained. Compared with TE, DIPIPE can improve the stability of ß-carotene during storage. In vitro digestion experiments showed that the bioaccessibility rate of ß-carotene in DIPIPE was less than that in TE. Cytotoxicity experiments showed that DIPI and ß-carotene micelles within a specific concentration range exerted no toxic effects on 3T3 cells. These results indicate that DIPIPE can be used as a good food-grade carrier for embedding and transporting active substances to broaden the application of the protein-based Pickering emulsion system in the development of functional foods.
RESUMO
Co3O4 nanorods were fabricated by the low-temperature hydrothermal method. The Co3O4 nanorods were formed through adding a small amount of surfactants (Polyvinylpyrrolidone, referred to as PVP) and reacting at 95 degrees C. Controlling the reaction time of preparation and pH of the solution can affect the properties of Co3O4 nanorods. X-ray diffraction (XRD), transmission electron microscopy (TEM) proved the as-prepared samples were Co3O4 nanorods in cubic phase. Hydrogen temperature programmed reduction (H2-TPR) and nitrogen adsorption-desorption experiment results showed that the size and pore structure of Co3O4 nanorods could be affected by different reaction time and pH, and led to the difference in specific surface area. The catalytic properties of Co3O4 nanorods were examined by degradation of gaseous toluene. The results showed that conversion of toluene was affected under low temperature by Co3O4 nanorods, which were prepared by different reaction time and pH. When the temperature was below 260 degrees C, the catalyst prepared in alkaline condition had the highest activity. However, when the temperature was higher than 260 degrees C, the conversion of toluene was hot significantly different.
Assuntos
Poluentes Atmosféricos/isolamento & purificação , Cobalto/química , Nanotubos/química , Óxidos/química , Tolueno/isolamento & purificação , Poluentes Atmosféricos/análise , Poluição do Ar/prevenção & controle , Catálise , Gases , Oxirredução , Tolueno/química , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/isolamento & purificaçãoRESUMO
The Si-doped TiO2 nanotubes photocatalysts was synthesized by anodic oxidation method, which used Na2SiF6/HF as an electrolyte, and was characterized by means of SEM, XRD, DRS and EDX. TiO2 nanotubes composed of anatase phase and rutile phase, and Si was highly dispersed on the wall of TiO2 nanotubes. The photocatalytic activity of the Si-doped TiO2 nanotubes was investigated for photocatalytic degradation of gaseous toluene. It was found that the photocatalytic activity of Si-doped TiO2 nanotubes, which prepared by 0.03 mol x L x (-1) Na2SiF6/HF and calcined at 400 degrees C for 1 h, was the highest. The conversion of toluene was 60% over the prepared Si doped TiO2 nanotubes under UV light, which was one times higher than that of pure TiO2 nanotubes.
Assuntos
Poluentes Atmosféricos/química , Nanotubos/química , Silício/química , Titânio/química , Compostos Orgânicos Voláteis/química , Poluentes Atmosféricos/isolamento & purificação , Catálise , Oxirredução , Processos Fotoquímicos , Tolueno/química , Tolueno/isolamento & purificação , Raios Ultravioleta , Compostos Orgânicos Voláteis/isolamento & purificaçãoRESUMO
In the title mol-ecule, C(11)H(16)NO(6)P, the nitro group is twisted out of the mean plane of the benzene ring at 29.91â (3)°. The two ethyl groups are disordered between two orientations in the ratios 0.784â (7)/0.216â (7) and 0.733â (6)/0.267â (6). Inter-molecular O-Hâ¯O hydrogen bonds link the mol-ecules into centrosymmetric dimers.
RESUMO
Sterically and electronically tunable and bifunctional organocatalysts have been developed and evaluated in the direct aldol reaction of heterocyclic ketones. Catalysts with different substituents showed variable catalytic efficiency for analogous substrates, indicating the importance of fine-tuning the strength of the hydrogen bonding in the two NH groups. The reactions all proceeded in good to high yield and with excellent enantioselectivities ranging from 90% to >99% ee. In most cases, high diastereoselectivities ranging from 96/4 to 99/1 were obtained for the anti aldol adduct.
Assuntos
Cetonas/químicaRESUMO
The TiO2 nanotube sample was prepared via a NaOH solution in a Teflon vessel at 150 degrees C. The as-prepared nanotubes were then treated with H2 SO4 solutions. The TiO2 nanotube has a crystalline structure with open-ended and multiwall morphologies. The TiO2 nanotubes before and after surface acid treatment were characterized by X-ray diffraction (XRD), scanning electron microscopy(SEM), transmission electron microscopy (TEM) and UV-VIS dispersive energy spectrophotometry (DRS). The photocatalytic activity of the samples was evaluated by photocatalytic degradation of acid orange II in aqueous solutions. It was found that the order of photocatalytic activity was as follows: TiO2 nanotubes treated with 1.0 mol/L H2SO4 solution (TiO2 (1.0M H2SO4) snanotubes) > TiO2 nanotubes treated with 0.2 mol/L H2SO4 solution (TiO2 (0.2M H2O4) nanotubes) > TiO2 nanotubes > TiO2 powder. This was attributed to the fact that TiO2 nanotubes treated with H2SO4 was composed of smaller particles and had higher specific surface areas. Furthermore, the smaller TiO2 particles were beneficial to the transfer and separation of photo-generated electrons and holes in the inner of and on the surface of TiO2 particles and reduced the recombination of photo-generated electrons and holes. Acid treatment was particularly effective for TiO2 nanotubes, this increase in activity was correlated with the concentration of H2 SO4 solution.
Assuntos
Poluição Ambiental/prevenção & controle , Nanotubos/química , Ácidos Sulfúricos/química , Titânio/química , Compostos Azo , Catálise , Microscopia Eletrônica , Nanotubos/ultraestrutura , Naftalenos , Fotólise , Espectrofotometria Ultravioleta , Difração de Raios XRESUMO
[reaction: see text] Readily tunable and bifunctional L-prolinamides as novel organocatalysts have been developed, and their catalytic activities were evaluated in the direct asymmetric Aldol reactions of various aromatic aldehydes and cyclohexanone. High isolated yields (up to 94%), enantioselectivities (up to 99% ee), and anti-diastereoselectivities (up to 99:1) were obtained under the optimal conditions.