Synthesis, Structure and Thermochromic Properties of a Copper(Ⅱ) Complex Based on Naphthyl Carboxylate and Benzimidazolyl Ligands

One novel copper(Ⅱ) complex, [Cu(NAA)2(bim)2]·H2O (1, HNAA = a-naphthylacetic acid, bim = benzimidazole) has been synthesized and characterized by X-ray single-crystal diffraction analysis, elemental analysis, and IR spectrum. It crystallizes in monoclinic, space group C2/c with a = 1.15969(12), b = 1.9757(2), c = 1.45763(16) nm, β = 104.712(2)°, V = 3.2298(6) nm3, Z = 4, C38H32N4O5Cu, Mr = 688.22, Dc = 1.418 g/cm-3, μ = 0.729 mm-1, S = 1.039, F(000) = 1428, the final R = 0.0380 and wR = 0.0912 for 2849 unique reflections. In 1, two carboxylate and two benzimidazole ligands coordinate to the central Cu(Ⅱ) atom by a bidentate chelate mode. Interesting, reversible thermochromic properties of 1 can be observed and investigated by thermal analysis method.     

Facile Fabrication of Nanoparticles Confined in Graphene Films and Their Electrochemical Properties

The development of novel nanostructured electrode materials with high performance and based on abundant elements is a key element in the societal pursuit of sustainable energy. Graphene‐based structures with rich macroporosity and high conductive networks are promising components to develop novel electrode materials. Herein, we described a facile procedure to confine Ni(OH)₂ particles in a graphene film, leading to a new sandwich‐like hybrid structure. The hybrid film offers simultaneously ordered ion diffusion channels and high electrical conductivity, which facilitate the improvement of both electrode kinetics and electrochemical stability, thus leading to high capacitance, fast rate capability, and stable cycle life as supercapacitor materials. This work provides a facile pathway for optimized structures for electrode materials, and represents a benefit for the global issues of energy shortage and environmental pollution.     

Thermal decomposition kinetic evaluation and its thermal hazards prediction of AIBN

AIBN (2,2′-azobis (isobutyronitrile)), widely used for blowing agent and initiator, is a typical self-reactive material, being capable of undergoing runaway reaction due to its self-heating during storage or transportation. In this study, the thermal decomposition process of AIBN was studied by differential scanning calorimetry at different heating rates. The kinetic parameters including the activation energy and pre-exponential factor at different stages were calculated, and the laws of parameter variation were analyzed using the software, named as Advanced Kinetics and Technology Solutions, which can also predict the thermal stability of decomposition process at actual situations, such as ton and kg scale. The results show that heating rate can influence evidently the thermal behavior of AIBN, which can decompose in liquid phase or in liquid–solid co-existing phase, or, even decomposes in solid phase; according to Friedman method, the value of the calculated activation energy is 122 kJ mol^?1; according to Ozawa method, the value decreases gradually with the reaction process, and the smallest one is 124 kJ mol^?1. By mg-scale prediction under isothermal condition, it is known that AIBN decomposes at 30 °C (room temperature), very slowly; by ton-scale prediction under adiabatic condition, the safety diagram of AIBN is acquired, which shows how the time to the maximum rate changes with the initial temperature under ideal adiabatic condition (Φ = 1), for example, for TMR_ad = 24 h, the corresponding mean temperature (i.e., TD₂₄) is 71.23 °C, and for the initial temperature 71.23 °C, the lower and upper limits of the confidence intervals (95 % probability) are 18.5 and 31 h; by kg-scale prediction, it is obtained that the self-accelerating decomposition temperature of 50 kg AIBN with standard package is 63 °C, which is close to that of ARC.     

自组装铝/氧化铜和铝/氧化铁及其性能评估

本文分别采用模板法制备氧化铜纳米花, 水热法制备氧化铁纳米环, 并自组装制备了铝-氧化铜和铝-氧化铁2种铝热剂。自组装增大了异相材料之间的接触, 分别使得铝-氧化铜的反应放热量和压力由523 J·g^-1、1 858 kPa增加至1 069 J·g^-1、 4 389 kPa;铝-氧化铁的反应放热量和压力由1 448 J·g^-1、749 kPa增加至2 039 J·g^-1、2 280 kPa。两种铝热剂的放热量和压力差别较大, 且铝-氧化铜的静电感度高于大多数含能材料, 铝-氧化铁的撞击感度特别低, 显示出不同的应用特点。     

静电纺丝制备g-C3N4/C纳米纤维及其可见光降解性能

采用g-C₃N₄纳米片与聚丙烯腈进行静电复合纺丝,再经预氧化和碳化制得g-C₃N₄/C纳米纤维。利用傅立叶变换红外光谱仪（FTIR）、X射线衍射仪（XRD）、拉曼光谱（Raman）和扫描电子显微镜（SEM）对样品结构和形貌进行表征,通过紫外-可见漫反射光谱（UV-Vis DRS）分析可见光响应性。研究表明,复合纳米纤维对罗丹明B表现出较好的可见光降解活性,源于无定形相/石墨相混合结构的碳基体能够降低g-C₃N₄的光生电子-空穴对复合的几率。复合纳米纤维膜在光催化降解搅拌条件下始终能保持完整,经过多次回收和光催化实验,对罗丹明B的光降解率依然较高,表现出较优异的循环利用稳定性。     

惰性盐辅助合成介孔石墨化碳片及其电容性能

以惰性盐KCl为模板、硝酸镍为金属催化剂镍源、葡萄糖为碳源,通过碳化处理制备了介孔石墨化碳片。利用扫描电子显微镜、透射电子显微镜、X-射线衍射仪和比表面测试仪对介孔石墨化碳片进行了表征。探讨了碳片形成的机理,采用三电极测试体系研究了介孔石墨化碳片电极材料的电化学性能。结果表明,10gKCl制备的碳片比表面积最大（989m²·g^-1）,在6mol·L^-1KOH电解液中,当电流密度为0.5A·g^-1时,比电容达到180F·g^-1;当电流密度达到10A·g^-1时,比电容维持在148F·g^-1,显示了电极具有较好的倍率性能;在10A·g^-1条件下,2000次循环充放电测试后电容没有发生衰减,展示了在超级电容器方面的应用潜力。     

A silica gel supported cobalt(Ⅱ) Schiff base complex as efficient and recyclable heterogeneous catalyst for the selective aerobic oxidation of alkyl aromatics

A silica gel supported cobalt(Ⅱ) Schiff base complex was synthesized and used for the oxidation of alkyl aromatics using molecular oxygen as an oxidant under atmosphere pressure.The catalyst shows a high conversion of alkyl aromatics and selectivity to benzylic ketones,and could be reused at least 5 times without significant loss of catalytic activity.     

ZrO2纳米粒子原位杂化PVDF膜的制备及其抗污染性能

针对传统聚合物膜抗污染性差的问题,本文从杂化膜结构设计出发,提出将ZrO2纳米粒子的原位制备和聚偏氟乙烯(PVDF)相转化成膜过程有机结合的制膜新方法.该方法将阴离子交换树脂引入到N,N-二甲基甲酰胺(DMF)中,以氧氯化锆为原料,利用阴离子交换树脂提供的―OH与无机盐的阴离子进行交换,得到ZrO2纳米粒子均匀分散的N,N-二甲基甲酰胺溶胶体系.随后将PVDF聚合物溶解到所得的N,N-二甲基甲酰胺溶胶体系中,获得均一、透明的铸膜液.利用X射线光电子能谱(XPS)和透射电子显微镜(TEM)对杂化膜中锆的存在状态和分散性能进行了表征.结果表明,ZrO2纳米粒子均匀分散在PVDF基体中,并且形成的纳米粒子的粒径约为10-20 nm.通过粘度、分相速度和膜形态的测定,研究了成膜机理.结果表明,ZrO2纳米粒子的引入加速了铸膜液成膜过程的分相速度.杂化膜的亲水性能通过接触角测定仪进行了评价.并选择以牛血清蛋白为代表模拟污染物,考察了杂化超滤膜的抗污染性能.结果表明,原位形成的ZrO2纳米粒子显著提高了膜的亲水性,减少了膜对蛋白质的吸附.这种将ZrO2纳米粒子的原位制备和PVDF相转化成膜过程有机结合的制膜新方法在有机-无机杂化膜的制备领域具有显著意义.     

2,4-二硝基甲苯热解自催化特性鉴别及其热解动力学

为研究2,4-二硝基甲苯(2,4-DNT)的热危险性及其分解反应的特征, 利用差示扫描量热仪(DSC)对该物质进行了动态扫描测试, 得到其起始分解温度T₀范围为272.4-303.5℃, 分解热ΔH_d约为2.22 kJ·g^-1. 在此基础上, 采用瑞士安全技术与保障研究所提出的快速鉴别法(瑞士方法)及数值模拟技术, 对其分解反应的特性参数进行了推算, 结果表明其分解具有自催化性. 采用Malek法分析了该物质分解反应的最概然机理函数并得出了相关动力学参数, 表明其分解具有自催化性且符合Sestak-Berggren 双参数自催化模型(SB模型), 这与瑞士方法所得结论一致. 采用等温DSC测试获得了该物质的‘钟形’热解曲线, 从而验证了两种方法的结论.     

Synthesis of 2-Azido-4-nitroimidazole and Its Derivatives for High-Energy Materials

2-Azido-4-nitroimidazole and its derivatives have been synthesized for energetic material applications. The synthesized compounds were fully characterized by 1H, 13C NMR spectroscopy and elemental analysis. Most of them were determined by single crystal X-ray diffraction. The calculated densities of the compounds range between 1.71 and 1.92 g,cm-3. The calculated detonation pressures （P） for these derivatives fall in the range of 25.17 to 32.62 GPa and the detonation velocities （D） are distributed from 7.65 to 8.55 km·s-1.