Preparation and physical properties of superhydrophobic papers

In this study, we developed a facile method for preparing a superhydrophobic paper surface using a multi-layer deposition of polydiallyldimethylammonium chloride (polyDADMAC) and silica particles, followed by a fluorination surface treatment with 1H,1H,2H,2H-perfluorooctyltriethoxysilane (POTS, CF(3)(CF(2))(5)CH(2)CH(2)Si(OC(2)H(5))(3)). The superhydrophobic wood fiber products prepared in this study have contact angles of water greater than 150 degrees and sliding angles less than 5 degrees. Besides their high water repelling property, the superhydrophobic paper products kept a high tensile strength at high relative humidity condition. The superhydrophobic paper products also showed high resistance to bacterial contamination.     

H2 storage and CO2 capture on a nanoscale metal organic framework with high thermal stability

A nanoscale aluminium-based metal organic framework (NMOF) with high thermal stability has been synthesized, which shows high H(2) and CO(2) uptake capacities and an excellent selectivity for CO(2) over N(2) and O(2).     

Mesoporous TiO2 core-shell spheres composed of nanocrystals with exposed high-energy facets: facile synthesis and formation mechanism

A facile new method that combines electrospray and hydrothermal treatment is used to prepare mesoporous core-shell TiO(2) spheres with high specific surface areas and high pore volumes. Interestingly, the resulting TiO(2) spheres are composed of anatase TiO(2) nanocrystals with exposed step-like {001} and smooth {010} facets. The percentage of exposed {001} facets can be adjusted by changing the experimental parameters used in the electrospray and hydrothermal treatment processes, such as the contents of poly(N-vinyl-2-pyrrolidone) and acetic acid. The combination of high specific surface area (>100 m(2) g(-1)), high pore volume (>0.30 cm(3) g(-1)), useful pore size (10-15 nm), spherical core-shell structure, and exposed high energy facets makes these TiO(2) spheres an important candidate for use in many photoelectrochemical applications. The formation mechanism of the mesoporous TiO(2) spheres is also studied. The great advantage of this method is that interesting and complicated mesoporous superstructures can be prepared using electrospray technology.     

Microstructural Exploration of the High Capacitance in RuO_2-ZrO_2 Coating

A high capacitance RuO₂-ZrO₂ coating was prepared by thermal decomposition method.Extended X-ray absorption fine structure(EXAFS),X-ray diffraction(XRD),high-resolution transmission electron microscope(HRTEM)and ab initio calculations were applied to understand the role of the microstructure in the acquisition of high specific capacitance of RuO₂-based oxides.The results show that the RuO₂-ZrO₂ oxide prepared at critical crystallization temperature can be considered to be quasi-amorphous or microcrystalline(A short-range ordered crystal structure can be seen from the TEM image,but no diffraction peaks can be seen from the XRD diffraction patterns).And this RuO₂-ZrO₂ was identified as a solid solution with high solid solubility.It referred to herein as a quasi-amorphous solid solution.Such a special microstructure was conducive for"synergistic catalysis"owing to the cationic interaction and thus could gain high"active site density"and high"active surface",thus developing high specific capacitance.     

Highly selective carbon dioxide adsorption in a water-stable indium-organic framework material

A metal-organic framework, with chiral 4(1) In(OH)(CO(2))(2) helix chains, exhibits a high CO(2) uptake under ambient conditions and outstanding selective separations of CO(2) from CH(4) or N(2). Its high stability toward humidity or even boiling water is confirmed by PXRD method.     

Mixed-ligand metal-organic frameworks with large pores: gas sorption properties and single-crystal-to-single-crystal transformation on guest exchange

Two isomorphous 3D metal-organic frameworks, {[Cu2(BPnDC)2(bpy)].8 DMF.6 H2O}n (1) and {[Zn2(BPnDC)2(dabco)].13 DMF.3 H2O}n (2), have been prepared by the solvothermal reactions of benzophenone 4,4'-dicarboxylic acid (H2BPnDC) with Cu(NO3)(2).2.5 H2O and 4,4'-bipyridine (bpy), and with Zn(NO3)(2).6 H2O and 4-diazabicyclo[2.2.2]octane (dabco), respectively. Compounds 1 and 2 are composed of paddle-wheel {M2(O2CR)4} cluster units, and they generate 2D channels with two different large pores (effective size of larger pore: 18.2 A for 1, 11.4 A for 2). The framework structure of desolvated solid, [Cu2(BPnDC)2(bpy)]n (SNU-6; SNU=Seoul National University), is the same as that of 1, as evidenced by powder X-ray diffraction patterns. SNU-6 exhibits high permanent porosity (1.05 cm3 g(-1)) with high Langmuir surface area (2910 m2 g(-1)). It shows high H2 gas storage capacity (1.68 wt % at 77 K and 1 atm; 4.87 wt % (excess) and 10.0 wt % (total) at 77 K and 70 bar) with high isosteric heat (7.74 kJ mol(-1)) of H2 adsorption as well as high CO2 adsorption capability (113.8 wt % at 195 K and 1 atm). Compound 2 undergoes a single-crystal-to-single-crystal transformation on guest exchange with n-hexane to provide {[Zn2(BPnDC)2(dabco)].6 (n-hexane).3 H2O}n (2hexane). The transformation involves dynamic motion of the molecular components in the crystal, mainly a bending motion of the square planes of the paddle-wheel units resulting from rotational rearrangement of phenyl rings and carboxylate planes of BPnDC2-.     

高比表面积Cr2O3-α-AIF3催化剂的制备和应用

采用炭硬模板法制备了高比表面积Cr2O3-α-AIF3催化剂.该催化剂的合成过程主要包括三步:(1)将一定浓度的蔗糖溶液浸渍到Cr203-y-Al2O3中,然后经过热处理,使得蔗糖分解为炭;(2)将含炭的Cr2O3-y-Al2O3固体在400℃用HF气体进行完全氟化;(3)在高温下利用燃烧法除去炭硬模板.对所制备的催化剂进行了X射线衍射(XRD),氮气吸脱附曲线,氨气程序升温脱附(NH3-TPD),透射电镜(TEM),扫描电镜(SEM)和X射线能量散射(EDX)技术表征.结果表明,氟化过程对Cr2O3-α-AIF3催化剂比表面积有重要影响,在最佳实验条件下,能够得到比表面积为115 m2·g-1的催化剂.此催化剂对催化裂解二氟乙烷(HFC-152a)制备氟乙烯(VF)的催化活性明显高于直接氟化制备的Cr2O3-α-AIF3催化剂,这是因为高比表面积的Cr2O3-α-AIF3催化剂具有较大的酸量.     

An 2-(2'-aminophenyl)benzoxazole-based OFF-ON fluorescent chemosensor for Zn2+ in aqueous solution

A water-soluble fluorescent sensor, 1, based on the "receptor-spacer-fluorophore" [2-(2'-aminophenyl)benzoxazole-amide-2-picolylamine] sensor platform, demonstrates the high sensitivity for Zn(2+) with a 25-fold fluorescence enhancement upon chelation to Zn(2+) and also exhibits high selectivity to Zn(2+) over other metal ions. X-ray crystal structure of Zn(2+) complex reveals that the amide oxygen (O2) cooperates with 2-picolylamine unit (N3, N4) as a receptor bind Zn(2+).     

2-step plasma-enhanced CVD for low-temperature fabrication of silica membranes with high gas-separation performance

Amorphous SiO(2) membranes were prepared via a 2-step plasma-enhanced CVD (PECVD) technique at room temperature on porous TiO(2)/Al(2)O(3) substrates. SiO(2) membranes showed molecular sieving properties with a high separation factor for He/N(2) and He/H(2), and high thermal stability, indicating the successful preparation of high-performance membranes at low temperatures.     

High extracellular Ca2+ alone stimulates osteoclast formation but inhibits in the presence of other osteoclastogenic factors

High ambient Ca2+ at bone resorption sites have been implicated to play an important role in the regulation of bone remodeling. The present study was performed to clarify the mode of high extracellular Ca2+ (Ca2+(e))-induced modulation of osteoclastogenesis and the expression of receptor activator of nuclear factor-kappaB ligand (RANKL) and osteoprotegerin (OPG), thereby to define its role in osteoclast formation. Mouse bone marrow cells were cocultured with osteoblastic cells in the absence or presence of osteoclastogenic factors such as 1,25-dihydroxyvitaminD3 (1,25-(OH)2vitD3)and macrophage colony-stimulating factor/soluble RANKL. Ca2+ concentration in media (1.8 mM) was adjusted to 3, 5, 7 or 10 mM. Osteoclast formation was confirmed by the appearance of tartrate-resistant acid phosphatase (TRAP)-positive multinuclear cells and the expression of osteoclast phenotypic markers (calcitonin receptor, vitronectin receptor, cathepsin K, matrix metalloproteinase-9, carbonic anhydrase 2). High Ca2+(e) alone significantly stimulated osteoclast formation in a dose-dependent manner. However, in the presence of highly osteoclastogenic factors, high Ca2+(e) significantly inhibited osteoclastogenesis. High Ca2+(e) alone continuously up-regulated RANKL expression while only transiently increased OPG expression. However, in the presence of 1,25-(OH)(2)vitD(3), high Ca2+(e) did not change the 1,25-(OH)2vitD3-induced RANKL expression while increased OPG expression. Taken together, these findings suggest that high Ca2+(e) alone increase osteoclastogenesis but inhibit in the presence of other osteoclastogenic factors. In addition, high CaCa2+(e)-induced osteoclastogenesis may be mediated by osteoblasts via up-regulation of RANKL expression. Meanwhile up-regulated OPG might participate in the inhibitory effect of high Ca2+(e) on 1,25-(OH)2vitD3-induced osteoclastogenesis.     

高硒情况下维生素E对老龄大鼠血清中抗氧化作用的影响

研究了高Se或高维生素E下，老龄大鼠体内抗氧化活性的变化以及高Se下维生素E对其体内抗氧化水平的影响。将十二月龄Wistar大鼠32只随机分成4组：（1）正常饲料组；（2）高Se饲料组；（3）高维生素E饲料组；（4）高Se高维生素E饲料组。饲至十周末，处死大鼠，按试剂盒要求取其血液制成血清测GSH－Px,SOD活性，MDA含量。结果表明，高Se或高维生素E下饲养下的大鼠与对照组比较，血清中GSH－Px活性升高（P＜0．05）。SOD活性未见改变，MDA含量分别减少50％和56％，有显著差异（P＜0．01）；维生素E与高Se合用与高Se组比较能进一步同GSH－Px,SOD活性（P＜0．01）。结论：高Se会升高老龄大鼠的抗氧化活性，而与维生素E合用更加升高老龄大鼠血液中抗氧化活性。     

Proton and electron conductivity in hydrous ruthenium oxides evaluated by electrochemical impedance spectroscopy: the origin of large capacitance

Electrochemical impedance spectroscopy was conducted on a series of hydrous ruthenium oxides, RuO(2).xH(2)O, (x = 0.5, 0.3, 0) and a layered ruthenic acid hydrate (H(0.2)RuO(2.1).nH(2)O) in order to evaluate their protonic and electronic conduction. The capacitor response frequency was observed at lower frequency for RuO(2).xH(2)O with higher water content, which was suggested to be due to electrolyte exhaustion within the film and/or utilization of hydrated interparticle micropores that have high ionic resistance. Analysis of the impedance data indicated that the charge-transfer resistance through the film is not significantly affected by the water content in RuO(2).xH(2)O, and the capacitor frequency response is dominated by the protonic conduction. The capacitor response frequency of layered H(0.2)RuO(2.1).nH(2)O was comparable to RuO(2).0.5H(2)O. The high specific capacitance at low frequency for layered H(0.2)RuO(2.1).nH(2)O is attributed to the utilization of the expandable hydrous interlayer, which accounts for the ionic conduction. The present results demonstrate the importance of hydrous regions (either interparticle or interlayer) to allow appreciable protonic conduction for high energy and high power electrochemical capacitors.     

Time-programmable pH: decarboxylation of nitroacetic acid allows the time-controlled rising of pH to a definite value

In this report it is shown that nitroacetic acid 1 (O₂NCH₂CO₂H) can be conveniently used to control the pH of a water solution over time. Time-programmable sequences of the kind pH_1(high)–pH_2(low)–pH_3(high) can be achieved, where both the extent of the initial pH jump (pH_1(high)–pH_2(low)) and the time required for the subsequent pH rising (pH_2(low)–pH_3(high)) can be predictably controlled by a judicious choice of the absolute and relative concentrations of the reagents (acid 1 and NaOH). Successive pH_1(high)–pH_2(low)–pH_3(high) sequences can be obtained by subsequent additions of acid 1. As a proof of concept, the method is applied to control over time the pH-dependent host–guest interaction between alpha-cyclodextrin and p-aminobenzoic acid.

Predictable and time-programmable sequences of the kind pH_1(high)–pH_2(low)–pH_3(high) in water solution are obtained by a judicious choice of the concentration of nitroacetic acid undergoing decarboxylation.     

新型二茂锆化合物(1,2-Ph2-4-PrCp)2ZrCl2的合成及催化烯烃聚合反应研究

3,4-二苯基环戊-2-烯-1-酮与丙基锂反应,经酸化脱水得新环戊二烯衍生物1,2-二苯基-4-丙基-1,3-环戊二烯(1).用丁基锂处理1得到相应的环戊二烯基锂,再与ZrCl₄在甲苯中反应,生成大立体阻碍二氯二茂锆化合物(1,2-Ph₂-4-PrCp)₂ZrCl₂(2).化合物1和2均经元素分析和核磁共振谱学表征.经甲基铝氧烷(MAO)活化,化合物2在较低Al/Zr比条件下既可有效地催化乙烯聚合,生成高分子量、高熔化温度聚乙烯.2/MAO体系对丙烯聚合表现出高活性,生成低分子量齐聚物,其分子量随聚合温度的降低而升高.     

Thermoelectric properties of Yb(x)Eu(1-x)Cd2Sb2

The thermoelectric performance of EuCd(2)Sb(2) and YbCd(2)Sb(2) was improved by mixed cation occupation. The composition, structure, and thermoelectric properties of Yb(x)Eu(1-x)Cd(2)Sb(2) (x=0, 0.5, 0.75, and 1) have been investigated. Polycrystalline samples are prepared by direct reaction of the elements. Thermoelectric properties were investigated after densification of the materials by spark plasma sintering. Yb(x)Eu(1-x)Cd(2)Sb(2) crystallizes in the P3m1 space group. The lattice parameters increase with the europium content. These materials show low electrical resistivity, high Seebeck coefficient, and low thermal conductivity together with high carrier concentration and high carrier mobility. ZT values of 0.88 and 0.97 are obtained for Yb(0.5)Eu(0.5)Cd(2)Sb(2) and Yb(0.75)Eu(0.25)Cd(2)Sb(2) at 650 K, respectively.     

二甲基二茂锆化合物(1,2-Ph2-4-MeCp)2 ZrMe2的合成及催化乙烯聚合反应研究

在惰性气氛下, 用2 mol甲基锂处理二(1,2-二苯基-4-甲基环戊二烯基)二氯化锆, 合成了大立体位阻的二甲基二茂锆化合物[(1,2-Ph2-4-MeCp)2ZrMe2]. 经元素分析、 核磁共振氢谱、 碳谱和X射线晶体衍射分析, 确定了该化合物的结构. 经Al( i Bu)3/Ph3C+B(C6F5)-4活化, 该化合物催化乙烯聚合反应显示出较高的催化活性, 生成高分子量及高熔点聚乙烯. 该体系的特点是在较低的n(Al)/n(Zr)比下即可有效地催化乙烯聚合.     

新型双极有机小分子化合物及其Al3+配合物的合成与发光

合成了一种新的具有“双极”(bipolar)性质的有机小分子蓝色发光材料2-(5-(4-(二苯胺基)苯基)-1,3,4-噁二唑-2-)苯酚［2(5-(4-(diphenylamino)phenyl)-1,3,4-oxadiazol-2-yl)phenol, HPOT］, 并以HPOT为配体, 与铝离子配位, 合成了三(2-(5-(4-(二苯胺基)苯基) 1,3,4-噁二唑-2-)苯酚)合铝［tri(2-(5-(4-(diphenylamino)phenyl)-1,3,4-oxadiazol-2-yl)phenonate)aluminum, AlPOT］配合物. 用 1 H NMR、 HRMS和元素分析进行了表征, 并测定了两种化合物的光致发光性质和热稳定性. 结果表明: 两种新化合物的热稳定性好, 光致发光性能优良, 是制作有机电致发光器件的候选材料.     

Highly diastereoselective Friedel-Crafts reaction of furans with 8-phenylmenthyl glyoxylate

The Friedel-Crafts reaction of (1R)-8-phenylmenthyl glyoxylate with variously substituted furans was found to be efficiently promoted by SnCl(4) or magnesium salts with high diastereoselectivities. MgBr(2) performs especially well under simple, undemanding conditions, giving both high yields and high diastereoselectivities (>90%). The reaction afforded chiral substituted furan-2-yl-hydroxyacetic acid esters, compounds of potentially high synthetic interest. [reaction: see text]     

以ZrO2-TiO2为载体的整体式锰基催化剂应用于低温NH3-SCR反应

以MnO2为活性组分, Fe2O3为助剂, 制备了以TiO2及ZrO2-TiO2为载体的整体式催化剂. 考察了它们在不同温度焙烧后应用于富氧条件下, NH3选择性催化还原(NH3-SCR)氮氧化物的低温反应性能和高温稳定性. 用X射线衍射(XRD)实验、比表面积测定(BET)、储氧性能测定(OSC)及程序升温还原(H2-TPR)等方法对催化剂进行了表征. 结果表明, 以ZrO2-TiO2为载体的催化剂具有很好的高温热稳定性, 并具有较高的比表面积和储氧能力, 同时具有较强的氧化能力. 催化剂的活性测试结果表明, 以ZrO2-TiO2为载体的整体式锰基催化剂明显地提高了NH3-SCR反应的低温活性, 具有良好的应用前景.     

醇改性剂对两种手性农药对映体拆分的影响

对两种手性农药马拉疏磷和粉唑醇进行了对映体的高效液相色谱手性拆分。使用纤维素-三（3,5-二甲基苯基氨基甲酸酯）手性固定相,流动相为正已烷,流动相中添加乙醇、丙醇、异丙醇、丁醇和异丁醇为改性剂,考察了各种醇含量对手性拆分的影响：实验结果显示,该固定相对两种手性农药都具有很好的分离效果。异丙醇、丁醇和异丁醇都适于作马拉疏磷对映体拆分的改性剂,而乙醇和丙醇的效果较差,对于粉唑醇,异丙醇改性剂的效果则相对较好。醇含量对拆分的影响趋势为：醇的含量减少会导致保留增强,分离效果增加。