Advanced Materials Research Vol. 663

Abstract: Breviflavone B is a novel chiral phytoestrogen that mimics the biological functions of 17β-estradiol (E2), an estrogen which is naturally produced in our body. It has exhibited a much higher estrogen receptor (ER) bioactivity than E2 or other phytoestrogens. Breviflavone B specifically activates ER at a low dose without activating other steroid receptors, and inhibits estrogen-stimulated breast cancer cell proliferation at high doses, making it a potential treatment option for breast cancer patients. In this report, a new liquid chromatography aprroach has been developed to isolate Breviflavone B from Epimedium Brevicornum herbal extracts. After passing through DIAION HP20 resin, the ethanolic extract of Epimedium Brevicornum was firstly fractionalized by a Diol column, then further separated by a C18 column using preparative HPLC, and finally purified by an ODS-MCR-HPS column in HPLC under gradient mode. In each stage of separation, the ER bioactivities of the each fraction were measured by estrogen receptor-driven reporter gene bioassays to guide the chromatographic fractionations. The results showed that the new combination of Diol and C18 and ODS-MCR-HPS column chromatography provided better separation selectivity than our previously-reported C18 column chromatography for isolation of Breviflavon B from Epemidium herbs. Pure Breviflavon B was successfully isolated from the ethanolic extract of Epimedium Brevicornum herb via this new approach of chromatographic fractionations guided by the bioassays.

Abstract: A neotype of silica microspheres were synthesized with chloropropyltrimethoxysilane (WD30) and tetraethoxysilane (TEOS) by sol-gel method. And the thermal properties of the filler both in nitrogen and in air condition were studied by means of thermogravimetric analysis. The morphology of the filler was measured by TEM. The so synthesized spheres were added into the silicone rubber whose mechanical strength was increased greatly. The molecular structure of the filler and the silicone rubber were characterized by FTIR. The possible strengthen mechanism of the filler was discussed. The neotype silica sphere researched in this paper could react with the PDMS chains which perfects the vulcanization of the silicone rubber. This kind of silica sphere exhibits many merits for usage as filler.

Abstract: In the present study, dc high voltage was applied to produce droplets with controlled diameter in wide range. The dc voltage was ranged from 0 to several kV. Water glass was atomized in alcohol solution into diameters of several ten μm, depending on dc voltage applied between nozzle and ground electrode. The atomized water glass droplets were solidified by removing water molecules from the water glass. When the dc voltage was raised, nozzle diameter and electrode distance were decreased, the diameter of silica particles was decreased.

Abstract: The preparation process of magnesium hydroxide, which was prepared by acid leaching method using dunite as material, was introduced. Dunite was firstly calcined for 4h at 700°C and treated by 4.0 mol/L of H2SO4 solution at 100°C for 2h. Secondly, the leaching solution was oxidized by H2O2, and ammonia was added in the solution to adjust its pH to 7.0-8.0. After the impurities were leached, the leaching solution was treated by 4.0 mol/L of NaOH and 2% of C11H23COONa, reacting for 1h, ageing for 2h. Then to obtain dried magnesium hydroxide, the insoluble compounds were dried by heat and magnesium hydroxide would be produced. The leaching rate of Mg2+ is 84.01%. XRD and SEM indicated that the shape of particles was platelet with a diameter of 150 nm. The product can reach the requirements of HG/T3607-2007 industrial product standard

Abstract: Graphic nanoporous copper (NPC) was prepared by a new method. Cu68Zn32 and Cu36Zn64 (atomic percentages) precursor alloy thin film was deposited by electro-deposition in acidic alloy plating solution and then dealloyed in hydrochloric acid to fabricate nanoporous copper (NPC) with pore size from 30nm to 100nm. The results show that the microstructure of NPC can be controlled by changing alloy plating solution and dealloying process, this process also maintains compatibility with micro-fabrication technique.

Abstract: An interposer model based on ordered metal microstructure reinforced polymer composite was established using ANSYS software. The shape of metal microstructure includes quadrilateral, hexagon and triangle. The stiffness and thermal conductivity of composite interposer was calculated and discussed. Simulation results show that the stiffness of the metal microstructure-reinforced polymer composite interposer increases with augmenting the volume fraction of metal compared with the pure polymer. For the composite with metal volume fraction of 65%, the stiffness of the triangular composite interposer is 3.12 times that of the pure polymer interposer. The thermal conductivity of the hexagonal model is the best, while the one of quadrilateral and triangular model is similar. For the composite with the metal volume fraction of 65%, the thermal conductivity of the triangular composite interposer is 3.42 times that of the pure polymer interposer. Therefore, metal microstructure can effectively improve the performance of the pure polymer interposer.

Abstract: In this paper, we prepared an octadecyltrichlorosilane(OTS) super-hydrophobic film using phase separation method to demonstrate the anti-icing property of super-hydrophobic surfaces. We investigated the super-hydrophobicity of the surface in -5°C environment, as well as the icing process of water droplets on the surface which proceeded at the temperature low to -15°C. We found that the prepared OTS film retained its super-hydrophobicity in the -5°C environment by the measurement of contact angle. It was observed that the icing progress of water droplets on the super-hydrophobic surface was greatly retarded. Based on the classical heterogeneous nucleation theory, it concluded that the ice formation is directly related to the surface wettability. This research would be beneficial to the preparation of anti-icing films.

Abstract: A new gas sensor was designed based on cataluminescence (CTL) by using catalytic reduction of benzene, toluene and xylene (BTEX) on the surface of nanosized catalyst Al₂O₃/Pt with hydrogen as the carrier gas. The result indicated that the sensor showed strong CTL response, high selectivity and excellent durability under optimal conditions: Al₂O₃/Pt (1%), the temperature of 395oC, the wavelength of 425 nm and the flow rate of 270 mL/min. The detection limit (3σ) is 0.2 ppm for benzene, 0.3 ppm for toluene and xylene. Other corresponding substances such as methanol, ethanol, formaldehyde, acetaldehyde, ethylacetate, ammonia and trichloromethane had no or less interference. It is a simple and convenient sensor with good selectivity and sensitivity for detecting BTEX.

Abstract: The pore size distribution and the microstructure of negative temperature concrete was studied with different temperature, combining with some testing methods, such as MIP and SEM. Moreover, the change of the compressive strength was also studied with different ages. In addition, the relationship between the microstructure and the macro-mechanical properties on negative temperature concrete was explored further with different freezing temperature. It indicated that the lower the early curing temperature, the looser the original structure of cement paste; the total volume of gel pore whose pore size was less than 20nm was decreasing apparently, and the compressive strength declined. When changing to standard curing, the pore size trended to be thinner, the compressive strength was increasing sharply. The concrete was cured from -5°C to standard curing, the volume of pore that was less than 200nm was equal to that of the concrete with the standard curing in the age of 28d, so was the compressive strength. However, the volume of the macro pore of the concrete curing under -10°C and -15°C was greater than the concrete curing the standard condition, the compressive strength was less.

Abstract: In this work, the micro-drop technology was applied to fabricate tunable LC microlens, which was composed of LC and UV curable polymers. The formed mechanism was significantly dependent on the dropped liquid volume, UV dose, and precuring time. The crater morphology of the microlens can be controlled by changing these parameters. The focal length of the proposed LC microlens can be electrically controlled from -5.6 cm to -22.4 cm.