Dual Effect of Manganese Oxide Micromotors: Catalytic Degradation and Adsorptive Bubble Separation of Organic Pollutants

Manganese oxide (MnO₂) based micromotors exhibiting a dual effect, that is, catalytic degradation and adsorptive bubble separation, were employed for water remediation. The dual effect of MnO₂ microparticles led to a greater than 90 % of decolorization of non‐biodegradable organic dyes in just 1 h, without the need for external agitation or bubble generation. These findings suggest high potential of MnO₂ micromotors for decontamination of organic pollutants from wastewaters or natural water reserves.     

硅片及其太阳电池的光衰规律研究

采用氙灯模拟太阳光源,将光强调至1000 W/m2,研究常规太阳能级单晶硅片、多晶硅片和物理提纯硅片的原片、去损减薄片、热氧化钝化片、双面镀氮化硅(SiN x:H)膜钝化片、碘酒钝化片以及太阳电池的光衰规律.利用WT-2000少子寿命测试仪以及太阳电池I-V特性测试仪分别对硅片的少子寿命和太阳电池的I-V特性参数随光照时间的变化进行了测试.结果表明:所有硅片以及太阳电池在光照的最初60 min内衰减很快随后衰减变慢,180 min之后光衰速率变得很小,几乎趋于零.     

Flow Characteristics of Partially Hydrolyzed Polyacrylamides during Converging into a Capillary

Partially hydrolyzed polyacrylamides (HPAMs) are the most widely used polymers in enhanced oil recovery (EOR). This study presents capillary flow measurements of three different molecular weight HPAMs in synthetic brine. Polymer solutions having similar viscoelasticity were forced to flow through a 0.23 mm (radius) stainless steel capillary to investigate their flow characteristics including mobility reduction (apparent viscosity) and mechanical stability, represented by the extent of mechanical degradation (DR). The results indicated that the apparent viscosity of the polymer solutions markedly dropped with increasing flow rate until 5 mL/min, corresponding to the shear rate of 8,730s^?1; after that a slight viscosity decrease was observed. The high-molecular-weight HPAMs (6.5 and 8.0 × 10⁶ g/mol) began to have slightly greater apparent viscosity than the low-molecular-weight HPAM (1.0×10⁶ g/mol) above the shear rate of 26,180 s^?1; this might result from the occurrence of the coil-stretch transition. All the HPAMs experienced very similar percentages of mechanical degradation (10%) at shear rates between 1750 and 8730 s^?1; however, above 8730s^?1 the high-molecular-weight HPAMs exhibited a steep increase in mechanical degradation (DR). On the other hand, in the case of the low-molecular-weight HPAM, the DR curve almost leveled off at 12%. Therefore, low-molecular-weight HPAMs are generally suggested for EOR applications. These results, we suggested, should be useful to improve the efficiency of polymer EOR by minimizing mechanical degradation.     

Sm2O3/TiO2对亚甲基蓝染料的光催化降解行为研究

采用浸渍法制备Sm2O3掺杂TiO2的负载型光催化剂Sm2O3/TiO2,考察其在紫外可见光区对亚甲基蓝的光降解行为.利用XRD、N2吸附、SEM、TEM、XPS和ICP-OES等手段表征Sm2O3/TiO2样品,考察Sm2 O3掺杂量和亚甲基蓝浓度对亚甲基蓝紫外光降解活性的影响和催化剂Sm2O3/TiO2的催化稳定性.结果表明,Sm2O3/TiO2对亚甲基蓝的紫外光降解活性高于TiO2,这归因子掺杂Sm2O3引起TiO2的晶体缺陷.这种晶体缺陷作为光生电子和空穴的陷阱实现光生电子-空穴对的有效分离,从而提高Sm2O3/TiO2的光催化活性.Sm2O3/TiO2对亚甲基蓝的光降解活性随着Sm2O3掺杂量的增加先增大后减小,随着亚甲基蓝浓度的增大而减小.Sm2 O3掺杂量5.0wt;的Sm2O3/TiO2对亚甲基蓝紫外光降解的7次循环实验未出现明显失活.     

吡啶鎓盐配体构筑的多钼酸基配合物的合成、结构及光催化性能

本文在水热条件下合成了一例同多钼酸阴离子[δ-Mo₈O₂₆]^4-基配合物[Co(bipbc)(δ-Mo₈O₂₆)_0.5(H₂O)₃] (bipbc=4,4-双[(4-羧基吡啶)甲基]联苯),其为一维链状结构,包含环型双核钴配合物[Co₂(bipbc)₂]⁴⁺和[δ-Mo₈O₂₆]^4-簇。该配合物结晶于单斜晶系,P2₁/n空间群,a=1.147 9(8) nm,b=1.440 9(11) nm,c=2.082 9(16) nm,β=93.469(2)°,V=3.438 8(4) nm³,Z=4,M_r=1 129.18,F(000)=2 204,μ=1.979 mm^-1,D_c=2.181 mg·m^-3,S=1.019,R₁=0.056 2,wR₂=0.137 7。光催化性质研究表明,在可见光、近红外光和全光谱的光照条件下,标题配合物对龙胆紫(GV)和亚甲基蓝(MB)的降解,表现出一定的光催化活性。     

层级纳米花环状Bi2O3/(BiO)2CO3复合材料光催化降解罗丹明B

通过程序升温水热法制备了层级纳米花状结构Bi₂O₃/（BiO）₂CO₃复合材料（简称BO/BCO）。采用X射线衍射（XRD）、紫外-可见漫反射吸收光谱（UV-Vis/DRS）、X射线光电子能谱（XPS）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）和氮气吸附-脱附测定等方法对上述合成材料的晶型结构、组成、光吸收性质、形貌和表面物理化学性质进行了表征。结果表明,该复合材料中（BiO）₂CO₃的晶型为四方相,Bi₂O₃的晶型为单斜相,复合后的材料同时具有两者晶型结构。并且,合成时随着OH-的引入与反应时间的增加,复合材料中（BiO）₂CO₃的特征衍射峰强度逐渐降低,Bi₂O₃的特征衍射峰强度逐渐增加,证明了Bi₂O₃在样品中所占比例的增加。从UV-Vis/DRS吸收光谱分析结果显示,与单体（BiO）₂CO₃和单体Bi₂O₃相比,合成的BO/BCO复合材料的吸收边带发生偏移,且Bi₂O₃的引入有效增加其可见光区吸收。同时,样品由片状（BiO）₂CO₃生长为层级纳米花环状结构的BO/BCO-0.5,而层级结构的形成导致BO/BCO-0.5的带隙能变窄,且对于光电子的反射与散射发生改变,从而有利于光生电荷的转移与光的吸收效率。另外,以罗丹明B为模型分子,通过不同光源照射下的光催化活性实验,循环实验以及捕获实验对复合材料BO/BCO的光催化活性进行了研究。结果表明,与其他体系（单体Bi₂O₃和P25）相比,BO/BCO-0.5活性有明显提高,并且在多次循环实验后依然保持良好的稳定性。为此,根据捕获实验结果推测了BO/BCO复合材料可能的光催化反应机理。     

Prodendronic polyamines from stable or labile methacrylates obtained by selective Michael addition onto asymmetric diacrylic compounds

A new synthetic strategy for the preparation of methacrylic monomers and polymers carrying acyl β‐amino groups is presented. The approach is based on the Michael addition of aliphatic amines onto asymmetric acrylic/methacrylic compounds, reacting the amine highly selectively with the acrylic unit while leaving the methacrylic moiety unreacted. The corresponding polymers are then obtained by conventional radical polymerization. The use of N,N,N′,N′‐tetraethyldiethylenetriamine (TEDETA) as the secondary amine leads to TEDETA moieties supported on polymeric chains. The new aminopolymers are sensitive to pH and to temperature exhibiting a lower critical solution temperature of between 50 and 90 °C. A further interesting feature of the new approach is that the stability toward hydrolysis of the side β‐amino acyl compounds was found to be dependent on whether an acrylamide or an acrylate is employed as the acrylic group of the asymmetric starting material. The esters exhibit an enhanced sensitivity to hydrolysis, compared to standard aliphatic esters, and decompose releasing a derivative of the amine precursor, within hours or weeks, depending on the pH and temperature conditions. The use of the amides leads to stable polymers when the same experimental conditions are applied. The novel dendronic polyamines have been proven to interact with DNA and to transfect cells with efficiency close to that obtained with polyethyleneimine vectors used as positive controls. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 2297–2305     

Air processed P3HT:PCBM photovoltaic cells: Morphology correlation to annealing,degradation, and recovery

Systematically varied annealing, encapsulation, and solvent vapor treatments are conducted to produce stable OPV devices with controlled film morphology and high performance when produced in air. Active layer films are analyzed by AFM, nanomechanical mapping, UV–vis spectroscopy, and XRD. Devices prepared with isopropanol solvent vapor annealing (SVA) combined with thermal annealing (TA) show the highest environmental resistance and performance. Such devices yield average PCE of 3.3%, with stability to atmospheric exposure of up to 60 min prior to encapsulation. Encapsulated devices exposed to the laboratory environment for 30 days exhibit a decrease in PCE of ～15%. On application of a second TA step PCE is recovered to over 90% of the original value. The unprecedented air stability of the cells is attributed to the formation of an active layer with a stable, favorable morphology during the SVA process, which is associated with lower oxygen content films. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014 , 52, 1511–1520     

Live‐Cell Quantitative Imaging of Proteome Degradation by Stimulated Raman Scattering

Protein degradation is a regulatory process essential to cell viability and its dysfunction is implicated in many diseases, such as aging and neurodegeneration. In this report, stimulated Raman scattering microscopy coupled with metabolic labeling with ¹³C‐phenylalanine is used to visualize protein degradation in living cells with subcellular resolution. We choose the ring breathing modes of endogenous ¹²C‐phenylalanine and incorporated ¹³C‐phenylalanine as protein markers for the original and nascent proteomes, respectively, and the decay of the former wasquantified through ¹²C/(¹²C+¹³C) ratio maps. We demonstrate time‐dependent imaging of proteomic degradation in mammalian cells under steady‐state conditions and various perturbations, including oxidative stress, cell differentiation, and huntingtin protein aggregation.