纳米零价铁活化分子氧原理及降解有机污染物性能增强策略

纳米零价铁直接还原降解有机污染物运行长效性差,且不能矿化有机污染物.利用纳米零价铁还原活化分子氧生成活性氧物种可以氧化甚至矿化有机污染物.在最近的研究中,作者提出了纳米零价铁活化分子氧的双途径机理,即铁核电子转移到氧化铁壳表面的双电子还原活化分子氧途径和氧化铁表面结合态亚铁离子的单电子还原活化分子氧途径,阐释了纳米零价铁核壳结构依赖的分子氧活化降解有机污染物性能机制及性能增强策略.证实在纳米零价铁活化分子氧体系添加少量亚铁离子能在零价铁表面形成更多的结合态亚铁,显著增强纳米铁表界面活性氧物种生成量;同时,在纳米零价铁活化分子氧体系中引入少量有机或无机配体亦可提高活性氧物种产生效率,从而增强有机污染物降解性能.最后讨论了典型环境因素如pH值、共存离子、天然有机物等影响纳米零价铁活化分子氧降解有机污染物性能的规律.     

微/纳米ZnO绒球的制备及其在自然光下催化降解有机染料性能

以谷氨酸氟硼酸(GluBF₄)离子液体水溶液为反应介质,以物质的量比为1:6的二水合醋酸锌[Zn(Ac)₂·2H₂O]和氢氧化钠为原料,室温下制备前驱体,再微波辅助加热制备了纳米氧化锌粉体,获得了纳米结构微米尺寸纳米ZnO绒球.利用场发射扫描电镜(FESEM)、X射线衍射(XRD)、比表面(BET)、能量色散谱(EDS)等对产物进行了表征.所得产物为六方晶系纤锌矿结构,粉体粒径20.4 nm,绒球比表面积为28.3 m²·g^-1,产物纯度较高,收率95.3%.同时探讨了纳米ZnO绒球生成的可能机理.该纳米材料在日光下显示较高的光催化活性和稳定性.分别配制浓度为10 mg·L^-1的100 mL甲基橙(MO)和甲基紫(MV)水溶液, 30 mg纳米氧化锌为光催化降解催化剂,太阳光激发下5 h脱色率分别达到74.3%和96.9%;溶液总有机碳(TOC)含量随光降解的进行缓慢下降;光催化剂重复利用5次,催化剂形貌不变、颜色不变,质量基本未发生变化.     

基于微纳结构液体灌注的超滑表面的制备与应用

超滑表面利用其基底上的微纳结构通过毛细作用将润滑油等液体锁定在孔隙中,孔隙中浸润的润滑油在基底形成一层动态油膜,油膜与不溶液体的液-液界面代替了固体与液体的固-液界面,从而大幅减少了滑动阻力。与传统具有类似低滚动角特性的超疏水和超疏油表面相比,孔隙中填充润滑油比空气具有更好的压力稳定性,而且润滑油的毛细流动性使得超滑表面具有良好的自修复能力。由于其明显的优势,近些年超滑表面已成为国际学术界研究热点,应用也拓展到防结冰、强化传热、减阻、抗生物黏附、微流控等领域。目前超滑表面研究仍存在重要挑战,例如如何避免润滑油的挥发带来的性能退化、如何针对各种材质和结构设计合适的加工工艺制备微纳结构等,这些问题限制了超滑表面的广泛应用。本文综述了超滑表面的制备工艺以及应用,分析了现存的问题,并且对超滑表面未来的发展趋势进行了展望。     

碳掺杂硼氮纳米管电子场发射的第一性原理研究

对闭口硼氮纳米管（BNNT）顶层掺碳体系,运用第一性原理研究了电子场发射性能.结果表明,掺碳的BNNT体系电子结构变化显著;外电场愈强,体系态密度向低能端移动幅度愈大,且最高占据分子轨道（HOMO）/最低未占据分子轨道（LUMO）能隙愈小.体系态密度和局域态密度,HOMO和LUMO及其能隙分析一致表明,各种碳掺杂体系中C_eqBNNT的场发射性能最佳. 关键词： 硼氮纳米管 碳掺杂 第一性原理     

有机溶剂热生长技术制备纳米CdS及其与聚苯胺复合膜的光学性能

以溶剂热生长技术(solvothermal technique)制备了半导体CdS的纳米微粒,并采用XRD、TEM、ED对其结构进行表征。在ITO导电玻璃上,采用电化学方法合成聚苯胺薄膜,以提拉的方法将CdS的纳米颗粒涂布其上,自组装得纳米CdS／PANI膜,并以荧光光谱(PL)及非线性Z-扫描法研究其光学特性。实验结果显示：经CdS修饰后,CdS／PANI膜的荧光发射峰强度增强,位置较单一PANI膜移至420nm处,同时经修饰后的复合物膜的非线性光学特性也有显著的提高。     

The first synthesis of 2-amino-1,4-dihydroquinolines

A versatile strategy is described for the synthesis of new 2-amino-1,4-dihydroquinolines. It involved a Knoevenagel condensation of N-protected-2-amino-5-bromobenzaldehyde with ethylcyanoacetate, followed by a cyclization and protection of the NH group to afford the key intermediates 7 or 19. Then various 1,4 addition reactions have been performed to introduce substituents on the upper part of the 2-amino-1,4-dihydroquinolines.     

An Amperometric Immunosensor Based on Layer‐by‐Layer Assembly of L‐Cysteine and Nanosized Prussian Blue on Gold Electrode for Determination of Human Chorionic Gonadotrophin

A novel amperometric immunosensor based on L ‐cysteine/nanosized Prussian blue bilayer films ({NPB/L ‐cys}₂) and gold nanoparticles (nano‐Au) was fabricated for determination of human chorionic gonadotrophin (HCG). First, L ‐cys and NPB was self‐assembled by layer‐by‐layer (LBL) technology to form {NPB/L ‐cys}₂ bilayer films on the gold electrode. Subsequently, nano‐Au layer was immobilized on the {NPB/L ‐cys}₂ bilayer films by electrodepositing gold chloride tetrahydrate and then anti‐HCG was assembly on the nano‐Au layer. Finally hemoglobin (Hb) was employed to block sites against nonspecific binding. With the electrocatalytic ability of Hb and NPB for the reduction of H₂O₂, the current signal of the antigen‐antibody reaction was amplified and the enhanced sensitivity was achieved. In this study, the assembly process and performance of the immunosensor were characterized by cyclic voltammetry (CV) and the morphology was researched by scanning electron microscopy (SEM). The immunosensor performed a high sensitivity and a wide linear response to HCG in two ranges from 0.5 to 10 mIU/mL and from 10 to 200 mIU/mL with a relatively low detection limit of 0.2 mIU/mL at 3 times the background noise, as well as good stability and long‐term life.     

Syndiotactic Polystyrene / Fullerene Composites: Elucidation of Structural Aspect

Summary: Syndiotactic polystyrene (sPS), an attractive polymer due to its wide range of application, forms polymer-solvent intercalates with a large variety of solvent molecules ranging from liquids to solids. Recently, it has been realized that sPS intercalate prepared from SPS/naphthalene gel is more promising of making mesoporous materials. Here, the composite of sPS/fullerene have been prepared by taking advantage of sublimation of naphthalene. The different techniques as like XRD, SEM, HRTEM, FT-IR, DSC, TGA etc have been employed to characterized sPS/fullerene composite. XRD investigation shows the presence of δ form sPS in the composite. SEM and HRTEM reveal the fibrillar network with fringe like structure in presence of fullerene only and the average diameter of fibril has increased as compared to pure sPS fibrils. The conductivities of these fibrils have been increased with increasing amount of fullerene.     

PEO‐Covered Nanoparticles by Emulsion Inversion Point (EIP) Method

This study reports the first PEO‐coated polymer nanoparticles synthesis by miniemulsion polymerization of nano‐emulsions prepared by the low‐energy emulsification method called EIP. The surfactant used was Brij 98, a PEO based non ionic commercial surfactant. The partial phase diagram of the system water/Brij 98/styrene was first determined. The Emulsion Inversion Point technique was then used on the water/Brij 98/styrene system to the formation of styrene‐in‐water nano‐emulsions. After miniemulsion polymerization, particle sizes as low as 36 nm were obtained. To the best of our knowledge, this method had not been used for polymerizable system up to now.

     

羟基磷灰石微球的制备、应用和功能化

羟基磷灰石(HA)是人体和动物骨骼的主要无机矿物成分。近年来,因HA具有特殊的表面特性和理化性能,良好的生物相容性、生物活性和骨传导作用,制备各种形态的HA材料成为从事生物、医学和材料的科研人员的研究重点。本文首先介绍了HA微球的制备方法,重点讨论了以聚合物为软模板以及用各种球形材料作为硬模板合成HA微球的制备方法,列出了不同方法制备HA微球的直径、孔径、比表面等各种性能参数。由于HA微球具有比表面积大、流动性好、质量轻、强度大,注射性能好,团聚能力低等HA块材不具有的特点,其在载体、骨修复材料、环境保护和色谱分离上有广泛的应用。针对HA微球在应用过程中遇到的问题,可采用表面改性或包覆、掺杂和将HA分散在其他基体中等措施对HA微球进行功能化修饰。HA 微球在控释载体、蛋白质分离以及细胞支架等方面具有极大的应用前景。