船舶水下减阻抗污涂层的研究综述

船舶由于在航行时受到各种阻力,消耗了大量能量,增加了航行成本。船舶水下阻力的来源可以大致分为船体阻力和生物质附加阻力。本文基于对阻力和生物质黏附形成过程的分析,介绍了水下减阻领域的进展突破,总结了具有减阻、抗污性质的涂层研究情况,从超疏水、超亲水减阻材料和自抛光防污涂料、低表面能抗黏附材料、防污剂等方面,对其中相关的科学问题和解决方法进行了综述。     

光致型形状记忆高分子材料

形状记忆高分子材料是当前的研究热点之一,其中光致型形状记忆高分子材料凭借其独特的优势受到研究者的广泛关注。本文综述了光致型形状记忆高分子材料的研究进展,分别介绍了该类材料的特性、分类、工作机理、应用研究和发展趋势。根据不同的形状记忆机理将该类材料分为光化学反应型和光热效应型,并重点对这两种类型的形状记忆高分子材料进行了描述。最后,对光致型形状记忆高分子材料的存在问题、发展方向和应用前景进行了展望。     

钠离子电池炭基负极材料研究进展

钠离子电池是目前新兴的低成本储能技术,因在大规模电化学储能中具有较好的应用前景而受到了国内外学者广泛的关注与研究。作为钠离子电池的关键电极材料之一,非石墨的炭质材料因具有储钠活性高、成本低廉、无毒无害等诸多优点,而被认为是钠离子电池实际应用时负极的最佳选择。本文详细综述了目前钠离子电池炭基负极材料的研究进展,重点介绍了炭质材料的储钠机理与特性,分析了炭材料结构与电化学性能之间的关系,探讨了其存在的问题,为钠离子电池炭基负极材料的发展提供有益的认识。     

聚乳酸阻燃性能的研究进展

聚乳酸作为一种资源与环境友好材料已得到了广泛深入的研究。如果能够提高聚乳酸的阻燃性能,则能进一步扩大其应用范围。目前对聚乳酸的阻燃改性主要采用添加阻燃剂的方法,并以磷系、氮系、硅系、金属化合物阻燃剂以及多种阻燃成分的复配为主,而聚乳酸的反应型阻燃也在不断研究发展中。本文在介绍阻燃作用机理的基础上,综述了聚乳酸阻燃研究发展现状,并对聚乳酸的阻燃提出展望。     

ZnO纳米粒子的光物理性质──微量水对荧光的影响

ZnO不仅是极其重要的半导体材料,而且还广泛用做化学反应的催化剂,光催化剂和光电转换材料。近年来,ZnO纳米粒子的制备和应用得到了广泛的研究,但许多问题并不十分清楚。譬如,对ZnO颗粒的可见荧光的发生机制就众说纷纭。Henglein等认为ZnO可见荧光由ZnO颗粒表面的阴离子空位引起,而Bahnemann等却认为可见荧光由被捕获的光生电子向被捕获的空穴越迁而引起。本文通过微量水对ZnO超微粒的荧光的影响的研究,进一步阐明ZnO荧光的产生机理。结果支持了Bahnemann的观点。     

高性能碳基与过渡金属化合物基超级电容器电极材料的研究进展

超级电容器因其在电动车和便携式设备上巨大的应用潜力而受到广泛关注. 电极材料是超级电容器的关键组成部分, 决定了超级电容器性能的好坏. 近来大量研究以碳材料和过渡金属化合物作为电极材料. 然而, 碳材料电容值极小与过渡金属化合物导电性和稳定性差, 极大地限制了它们在超级电容器中的应用. 本综述重点介绍了我们课题组近年来在设计、可控制备及优化碳材料与过渡金属氧/氮化物电容性能的相关研究工作, 并讨论了材料构效关系及其调控机理. 最后对碳材料和过渡金属化合物作为电极材料的日后研究进行了展望.     

金属有机骨架材料在轻烃分离中的应用

金属有机骨架材料(metal-organic frameworks,MOFs)是一种由金属离子或金属簇通过与有机配体自组装而形成的新型材料。近年来,金属有机骨架材料在轻烃(包括甲烷、乙炔、乙烯、乙烷、丙烯和丙烷)分离方面引起了广泛兴趣。本文简要地介绍了多种金属有机骨架材料分离不同轻烃气体的最新研究进展,并对影响分离效果的因素与研究前景进行了总结和展望。     

胶体量子阱发光二极管的研究进展

胶体量子阱(CQW)由于具有高色纯度、高光致发光量子效率、光色可调等优异的光电性能，近年来成为一种新型的光电材料，广泛用于制备发光二极管、激光、探测器、太阳能电池等半导体器件。其中，基于CQW的发光二极管(CQW-LED)因为具备极窄的光谱、极佳的色纯度、高效率、可溶液加工、可柔性化等优点，在显示和照明等领域展现出重要应用前景，受到学术界和工业界的广泛重视而成为研究热点。本文首先介绍了CQW-LED中的一些基本概念，包括CQW材料特性、LED器件结构、发光机理等；然后从CQW材料种类的角度出发，阐述了基于单核型、核/冠型、核/壳型、复杂异质结型、以及杂质掺杂型CQW-LED近年来的研究进展，并结合我们研究团队最近的工作详细的介绍了实现高性能CQW-LED的方法，包括对材料选取、设计策略、器件结构、器件性能、工作机理以及发光过程的分析；接着，介绍了CQW-LED的集成应用；最后探讨了CQW-LED目前面临的挑战及其未来的发展机遇。     

导电自修复材料的研究进展

导电高分子材料因具备良好的导电性、质轻和易加工特性而被广泛应用于航空、生物医学设备、化学生物传感器和能源等领域。然而,导电高分子材料在使用过程中不可避免地会产生微裂纹,从而破坏导电通路并使整个电子设备瘫痪。受生物体启发,设计和构筑具备自修复功能的导电高分子材料是研究的热点。本文介绍了导电自修复材料的最新研究动态,综述了自修复机理和材料的制备方法及应用前景,最后简要分析导电自修复材料目前存在的主要问题并展望其发展方向。     

银纳米材料表面增强拉曼散射基底研究进展

表面增强拉曼散射（SERS）技术在环境保护、食品工业、医学检测、生物检测等领域有广泛的应用前景。SERS基底材料和结构是影响性能的关键因素,而银纳米材料SERS基底已被广泛应用。本文介绍了SERS基底的增强机理,对近年来纯银纳米材料和银基复合纳米材料SERS基底的研究进展进行了综述,并介绍了银纳米材料SERS基底发展面临的问题,对其发展趋势进行了分析和展望。     

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%.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Selective syntheses of 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones via temperature-dependent Rh(II)-carbenoid-mediated 2H-azirine-ring expansion

The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.     

Copper catalyzed/mediated synthetic methodology for ebselen and related isoselenazolones

Scope of the copper catalyzed/mediated selenium-nitrogen coupling reaction has been studied for the synthesis of isoselenazolones. It is noticed that the 2-chloro, 2-bromo-, and 2-iodo-aryl amides substrates can be exploited in the selenium-nitrogen coupling reaction by employing 25-100 mol % of CuI/1,10-phenanthroline (L) and potassium carbonate as a base in DMF. Furthermore, electron rich 2-chloro-arylamides also underwent selenium-nitrogen coupling reaction to give biologically important selenium-nitrogen heterocycles. Also, copper-catalyzed selenium-nitrogen coupling reaction has been meticulously applied for the synthesis of diaryl diselenides having methoxy, amine, and amide functionality from respective aryl iodides in the presence of stoichiometric amount of succinimide as an external Se-N coupling partner.     

Knoevenagel condensation catalyzed by novel Nmm-based ionic liquids in water

A series of novel N-methyl morpholine (Nmm) based ionic liquids with 1,2-propanediol group were synthesized and used as catalysts for Knoevenagel condensation at room temperature in water. Under the effect of the catalyst, various aldehydes or aliphatic ketones could react with a wide range of activated methylene compounds well, including malononitrile, alkyl cyanoacetate, cyanoacetamide, β-diketone, barbituric acid, 2-arylacetonitrile and thiazolidinedione. Furthermore, most of the products could be separated just by filtrating and washing with water. Additionally, the catalyst is recyclable and applicable for the large-scale synthesis.     

Construction of polyheterocyclic spirotetrahydrothiophene derivatives via sulfa-Michael/aldol cascade reaction

A series of polyheterocyclic spirotetrahydrothiophene derivatives were obtained in moderate to excellent yields via a catalyst-free sulfa-Michael/aldol cascade reaction of chalcones 1 and commercially available 1,4-dithiane-2,5-diol 2 under mild conditions. We also present the first asymmetric sulfa-Michael/aldol cascade reaction of chalcones 1 and commercially available 1,4-dithiane-2,5-diol 2 with moderate to good enantioselectivities catalyzed by readily available chiral phase-transfer catalysts (PTCs).     

Suzuki-Miyaura reactions of the soluble guanylate cyclase inhibitor NS2028: a non-product specific route to C-8 substituted analogues

Both soluble guanylate cyclase (sGC) inhibitors ODQ 1 and NS2028 2 are synthesized via improved protocols. In the former case treating 3,4-dihydroquinoxalin-2(1H)-one oxime 8, which can be prepared in two steps from 1,2-benzenediamine, with 1,1′-carbonyldiimidazole (CDI) gives the dihydro-ODQ 10 that in the presence of KMnO₄ oxidises to give ODQ 1 in an overall yield of 46% starting from 1,2-benzenediamine. In the latter case, the synthesis affords NS2028 2 from 2-amino-4-bromophenol 3 in three steps with an overall yield of 85% and avoids the need for chromatography. Furthermore, Suzuki-Miyaura reaction conditions are described that enable the preparation of 8-aryl and 8-heteroaryl derivatives of NS2028 directly from NS2028 2. Finally, demethylation of the 8-(methoxyphenyl) substituted analogues afforded the 8-(hydroxyphenyl) derivatives 40-42. All new products are fully characterised.