丝网印刷法制备纳米银线透明导电薄膜

以高纯纳米银线作为导电介质,采用低成本丝网印刷法在普通透明玻璃基底上制备纳米银线薄膜层。经低温退火处理后,采用冷场发射扫描电子显微镜对薄膜的形貌进行表征;分别采用紫外可见分光光度计和四探针测试仪对薄膜的光学透过率和导电性能进行测试。实验系统研究了印刷浆料中纳米银线的含量、印刷层数和退火温度对薄膜的光学透过率和导电性能的影响。当印刷浆料中纳米银线的含量为3%(w/w),印刷层数达到3层,经低温275℃退火后,可制备出光电性能良好的纳米银线薄膜,该薄膜最大可见光透过率为39.4%,表面方块电阻仅为25.6Ω·□~(-1)。     

透明PANI/ATO杂化导电薄膜的制备与表征

以聚苯胺和掺锑的氧化锡作为主要原料、采用溶胶-凝胶法制备了新型有机-无机杂化的透明导电薄膜，薄膜的可见光透过率为80%以上、电导率达到1~10 S·cm^-1。着重研究了制备过程中热处理温度、引入水量以及浸涂液浓度对薄膜的结构、可见光透过率和电导率的影响。确定了薄膜的最佳工艺条件为： 热处理温度为300 ℃、引入水量为R_w = 12、浸涂液的浓度为114 g·L^-1。浸涂液的粘度可在长达25 d的时间内保持稳定。     

银负载量对网状TiO2柔性薄膜电极储锂性能的影响

本工作采用水热法结合银镜反应制备出一系列不同Ag负载量（2.2%、4.0%、6.4%,w/w）改性的3D纳米网状结构Ag@TiO₂薄膜电极。利用电感耦合等离子体技术（ICP）、X射线衍射（XRD）、扫描电镜（SEM）、透射电镜（TEM）和X射线能谱（EDX）等表征手段测试所合成材料的形貌及成分,实验结果表明Ag纳米颗粒可以成功沉积在TiO₂纳米线表面。电化学测试数据则表明,4.0%（w/w）负载量的Ag@TiO₂相比于未改性和其他负载量的TiO₂纳米线具有更好的倍率性能和更稳定的可逆容量。在50,100,200,400,800和1 200 mA·g^-1的电流密度条件下,该改性电极的放电容量可分别达到261.4,253.7,239.5,216.5,193.1和185.1 mAh·g^-1,在200 mA·g^-1下循环80次后容量保持率仍能达到99.8%。     

介孔氧化钨电色薄膜的制备与性能研究

采用一种新的非离子型gemini表面活性剂结构导向模板, 成功制备了介孔氧化钨薄膜. 通过SAXRD, TEM和N₂吸附-脱附等方法考察薄膜的制备和微结构特性, 发现获得的产物具有三维蠕虫介孔结构, 比表面积可达145.5 m²• g^－1. 测定了该薄膜在无水高氯酸锂/碳酸丙烯酯电解质溶液中的循环伏安和电致变色性能, 并与无模板薄膜进行了对比研究. 研究表明, 由于具有更大的电化学活性比表面, 纳米介孔氧化钨薄膜表现出增强的电色性能, 在633 nm波长处的透过率调制幅度可达60%以上, 着色效率为51.7 cm²•C^－1.     

CuO-SiO2和Cu2O-SiO2薄膜的制备及其光学性能

以CuSO₄·5H₂O和正硅酸乙酯为前驱体,配制了稳定透明的Cu²⁺-SiO₂复合溶胶电解液。采用电化学-溶胶凝胶方法,在恒电位-0.9 V下得到Cu-SiO₂复合膜,该复合薄膜分别在250和450℃的热处理后得到Cu₂O-SiO₂和CuO-SiO₂复合薄膜。采用XRD、SEM/EDX和台阶仪表征了复合薄膜的组成、形貌和厚度;采用紫外-可见光谱和Z扫描技术研究了复合薄膜的线性和三阶非线性光学性能。结果表明Cu₂O-SiO₂和CuO-SiO₂复合薄膜中的Cu含量、Cu的形态（如Cu₂O、CuO）及Cu₂O或CuO颗粒大小影响薄膜的光学带隙和三阶非线性光学性能,2种薄膜的光学带隙分别是2.67和2.54 eV,三阶非线性极化率χ^（3）分别为2.31×10^-6和1.36×10^-6 esu。     

钇离子掺杂对二氧化钛纳米薄膜光诱导超亲水性能的影响及其机理

用溶胶-凝胶法和浸渍-提拉法工艺,在玻璃表面上制备了均匀、透明的钇离子(Y³⁺)掺杂二氧化钛纳米薄膜。用XRD分析了样品的晶相及其与热处理温度的关系,用X射线光电子能谱(XPS)分析了薄膜表面氧的状态,用可见光吸收光谱分析了涂膜层数对透光率的影响,用接触角仪测定了其亲水性。研究了Y³⁺掺杂本身和具体的掺杂量、光照强度和时间对薄膜亲水性的影响。研究结果表明,掺杂Y³⁺的二氧化钛纳米薄膜,在物质的量分数x(Y³⁺/Ti⁴⁺)=1.5%时,经紫外光照30min或自然光照1h后,与水的接触角小于5°,表现出超亲水性;与纯二氧化钛纳米薄膜相比,其超亲水性对光诱导更为敏感;在有实用意义的超亲水性的稳定方面也有明显的改善;这应部分地与固体化学所描述的Y³⁺掺杂所造成固定、额外并且是高浓度的氧空位有关。     

溶胶-凝胶方法制备ZnO:Al薄膜及其制备工艺条件研究

采用Sol-Gel工艺在玻璃基片上制备出C轴择优取向性、高可见光透过率以及高电导率的Al³⁺离子掺杂的ZnO透明导电薄膜ZnO:Al(ZAO薄膜).并研究了退火温度、Al掺杂量等对其光电性能的影响.结果表明,溶胶-凝胶法制备ZAO薄膜的最佳工艺条件为:溶胶浓度0.75 mol/L、掺杂量1.5 atm%,镀膜层数10层(厚度约为136 nm)、退火温度600℃.     

等离激元增强上转换发光及其分子检测应用

针对荧光分子检测普遍灵敏度低和检测范围窄的问题,制备了具有等离子激元共振特性的重掺杂半导体纳米结构Cu_2-xS和典型的稀土掺杂上转换发光纳米颗粒NaYF₄∶Yb,Er,通过三相界面自组装方法获得了Cu_2-xS/NaYF₄∶Yb,Er薄膜基底。结合有限元模拟,计算了不同摆放情况下Cu_2-xS周围的局域电场分布,研究了在实际薄膜中Cu_2-xS纳米盘之间产生的等离激元耦合对上转换发光性能以及对拉曼信号增强的影响。结果表明,Cu_2-xS等离激元层与NaYF₄∶Yb,Er发光层的耦合,不仅得到了上转换 3个数量级的提高,还实现了分子检测 10^-7 mol·L^-1的检测极限,并且获得了 10^-3~10^-7 mol·L^-1的宽线性响应,从而达到高灵敏度的定性和定量双功能的精确检测。     

等离激元增强上转换发光及其分子检测应用

针对荧光分子检测普遍灵敏度低和检测范围窄的问题,制备了具有等离子激元共振特性的重掺杂半导体纳米结构Cu_2-xS和典型的稀土掺杂上转换发光纳米颗粒NaYF₄：Yb,Er,通过三相界面自组装方法获得了Cu_2-xS/NaYF₄：Yb,Er薄膜基底。结合有限元模拟,计算了不同摆放情况下Cu_2-xS周围的局域电场分布,研究了在实际薄膜中Cu_2-xS纳米盘之间产生的等离激元耦合对上转换发光性能以及对拉曼信号增强的影响。结果表明,Cu_2-xS等离激元层与NaYF₄：Yb,Er发光层的耦合,不仅得到了上转换3个数量级的提高,还实现了分子检测10^-7 mol·L^-1的检测极限,并且获得了10^-3~10^-7 mol·L^-1的宽线性响应,从而达到高灵敏度的定性和定量双功能的精确检测。     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.