光热材料在海水淡化领域的近期研究进展与展望

太阳能水蒸发系统成本低、能效高,对缓解能源危机、减少水污染、促进海水淡化具有重要意义.然而,太阳能驱动水蒸发的自然机制往往受到低蒸发率和吸收光谱范围小的影响.其中,局部加热并限制热损失的界面水蒸发策略被广泛认可并作为高性能、可持续的太阳能蒸汽产生的有效途径.随着太阳能水蒸发技术的不断发展,制备绿色、高效的光热材料已成为研究热点.根据光热材料的种类将其划分为:金属材料、半导体材料、碳基材料以及聚合物材料,详细阐述了不同材料的光热转换机制并总结近年来光热材料在海水淡化领域的研究现状及进展;讨论了潜在的光热候选材料,对其未来发展做出了展望.旨在为海水淡化领域中高效光热材料的合理设计和开发提供可行方案,对今后光热材料的发展具有总结和指导意义.     

超浸润油水分离材料的研究进展

海洋石油泄露和工业废水违规排放造成了严重的环境和生态污染。近年来,受荷叶、水黾、鲨鱼等动植物组织结构的启发,超浸润材料的设计与开发成为当前研究的热点之一,在油水分离领域展现出十分重要的实际应用价值。本文首先介绍了表面浸润性的基本理论,然后综述了近年来包括超疏水型、超亲水型、Janus型以及功能型超浸润油水分离材料的研究进展,最后总结了目前该领域存在的一些问题,并指出利用简单环保的方法开发出低成本、耐久性和高效分离能力的超浸润油水分离材料将会是该领域的主要发展方向。     

超疏水油水分离材料研究进展

近年来,石油泄漏和有机污染物排放对环境和生态系统造成了严重甚至不可挽回的损害,油水分离已成为一个全球性的挑战,如何处理油水混合物并将其有效分离已成为目前亟待解决的问题.许多仿生超疏水材料已被用于选择性油水分离研究,显示出诱人的应用前景.本文作者简要介绍了自然界超疏水现象以及固体表面浸润性理论,分析了材料的疏水亲油原理,重点介绍了近年来超疏水油水分离材料的研究应用进展,并对本领域的研究趋势进行了展望.     

油水分离用超疏水纤维素基织物的制备及研究进展

近年来,石油泄漏和有机污染物排放对海洋环境和人类健康造成了严重的危害,开发高效、耐用的油水分离材料处理含油废水势在必行.纤维素基织物由于其多孔性、可再生性及优异的柔韧性在油水分离材料的制备中受到广泛的关注.本文详细介绍和讨论了各种不同方法制备超疏水纤维素基织物的研究现状,并阐述了超疏水纤维素基织物在油水分离中的应用,最...     

网状骨架CVD生长碳纳米管用于重盐水脱盐

目前,太阳能海水淡化领域通过光子管理、纳米尺度热调控、开发新型光热转换材料、设计高效光吸收太阳能蒸馏器等方法实现了界面太阳能驱动蒸汽生成,这种绿色、可持续的脱盐技术已成为近年来的研究热点。碳基材料如碳纳米管、石墨烯、炭黑、石墨等都有涵盖整个太阳光光谱的光吸收能力,是一类新型的光热转换材料。本文通过对材料进行微结构设计,使用化学气相沉积(CVD)技术,在不锈钢网状骨架上生长碳纳米管形成光热转换活性区,以实现高效光吸收、光热转换,并进一步设计了房屋型太阳能蒸发器,其中盐水表面被微米网状-碳纳米管蒸发膜覆盖,利用光热转换过程产生的热量驱动重盐水中的水蒸发产生水蒸气,最后对水蒸气进行冷凝回收实现脱盐。实验结果表明,当光照强度为1个太阳光(1 kW·m~(-2))时,膜表面温度迅速升高并稳定于84.37°C,对于重盐水(100 g·L~(-1) NaCl)的脱盐率达到99.92%,可实现稳定持续的重盐水脱盐。这种方法可用于构建多孔界面光热转换脱盐系统,对设计界面光蒸汽转化膜材料及器件,实现规模化海水淡化具有重要的意义。     

超亲水超疏油油水分离膜的制备及其性能

超亲水-超疏油油水分离膜是一种过水隔油的特殊分离膜,在处理海洋溢油污染、环境含油废水时具有保持分离膜不被油污染的优势,有十分重要的实际意义。为了掌握近年来超亲水超疏油分离膜的发展动态,本文首先以液体静压力与毛细作用力为基础阐述亲水疏油膜的油水分离机理;然后分类概括超亲水-超疏油金属基底网膜、刺激响应油水分离膜、无基底聚合物膜材料的制备及各项性能的研究新进展;最后总结目前在该领域仍存在的问题并进行展望。     

超亲水疏油材料的制备及其油水分离性能

含油污水的随意排放对海洋、沿海周边环境以及人类健康造成了严重的影响。传统的油水分离方法易造成环境二次污染,同时也是对有限资源的一种损耗。因此,如何高效环保地解决含油污水问题具有重要意义。物理过滤/吸附法被认为是一种高效环保的分离方法,基于仿生学原理,许多可用于物理选择性分离的超亲油疏水和超亲水疏油材料被制备出来。超亲油疏水材料易被油污染,重复利用率低;相比之下,超亲水疏油材料具有自清洁性且重复利用率高,在油水分离方面具有广阔的应用前景。根据基底材料的选择不同,本文综述了金属基以及高分子基超亲水疏油材料的研究现状,总结了其优缺点,并对今后超亲水疏油材料的研究方向和重点进行了展望。     

MXenes复合材料的发展:界面调控及结构设计

MXenes作为一类新兴的二维材料, 因具有独特的亲水性、 优异的力学性能、 丰富的表面官能团、 高导电率、 光热以及光电效应等性能而成为研究热点, 广泛应用在电磁屏蔽、 电化学储能、 生物医药、 分离、 传感器和海水淡化等领域. 虽然MXenes具有这些优异的性能, 但是其存在的与疏水性高分子相容性差、 带负电的官能团阻碍电解质运输及易氧化等问题限制了其实际应用. 近年来, 通过对MXenes进行界面调控以解决其固有缺陷, 并在此基础上对MXenes进行针对性的结构设计以提升界面稳定性, 其性能得到了进一步提升. 本文对MXenes复合材料发展过程中在界面调控和结构设计方面的研究进展进行总结, 并重点介绍了MXenes的结构和性质及MXenes在复合材料中的界面调控手段, 对MXenes复合材料的结构设计进行了阐述, 并对MXenes复合材料的发展前景进行了展望.     

基于特殊润湿性材料的油水分离

频繁发生的石油泄漏事故以及工业含油污水的违规排放不仅造成了巨大的经济损失,而且严重破坏了人类赖以生存的生态环境。为了净化被油污染的水域,研究者们近年来开始研究出了各种特殊润湿性(如超疏水或超疏油)的材料用于实现油水分离。超疏水和超疏油可以通过设计材料表面的微观几何形貌和化学分子组成来获得。通过各种微纳制备手段使材料表现出对油和水截然相反的极端润湿性,是这类材料实现油水分离的关键所在。本文首先阐述了实现油水分离的重要意义,并介绍了材料表面润湿性的相关理论基础。根据材料对水和油所表现出的不同超疏液性与超亲液性,对油水分离材料从以下三类分别介绍：(ⅰ)超疏水/超亲油材料,(ⅱ)超疏油/超亲水材料,(ⅲ)智能响应润湿性材料。对于每一类油水分离材料,本文概括了国际上近期相关的代表性研究工作,包括材料的制备方法和实现油水分离的原理和过程,以及这些材料的主要特点和应用。最后,针对基于特殊润湿性材料实现油水分离,探讨了该研究领域目前存在的主要问题和面临的挑战,并对该领域的应用前景进行了展望。     

生物质基油水分离膜的应用现状及前景展望

随着当前全球石化行业的快速发展,水资源的短缺和工业废水排放的增长已经极大地阻碍了社会和环境的可持续性发展。含油废水是其中占比最大也是比较难处理的一种废水,膜分离法是目前处理含油废水的有效方法之一。而目前市场上主流的油水分离膜部分或全部使用了不可再生和非降解性原料,会对环境造成二次污染。以生物质材料为主要原材料的生物质基油水分离膜以其绿色、可持续、高效、可降解等优势得到了极大地关注。本文从生物质基油水分离膜的生物质来源、种类、相应的制备及改性方法、应用研究现状及主要问题进行论述,对未来生物质基油水分离膜的前景进行展望。     

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%.     

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.     

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.     

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.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

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.     

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.     

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.