超高效液相色谱-静电场轨道阱高分辨质谱法同时测定合成革中8种异氰酸酯残留

建立了超高效液相色谱-静电场轨道阱高分辨质谱（UPLC-Orbitrap HRMS）同时测定合成革中8种异氰酸酯残留的方法。样品中残留的异氰酸酯经二氯甲烷超声萃取后,用9-甲氨基甲基蒽（MAMA）进行衍生,衍生产物浓缩定容后进行UPLC-Orbitrap HRMS分析,外标法定量。衍生产物在Hypersil GOLD色谱柱（100 mm×2.1 mm,1.9 μm）上进行分离,流动相为乙腈-0.1%（v/v）甲酸水溶液,采用电喷雾正离子（ESI⁺）模式电离,以保留时间和准分子离子精确质量数定性,以提取离子色谱峰面积定量。各组分的定量限均为0.2 μg/kg,在3个加标浓度水平下,方法的平均加标回收率为85.41%～95.53%,相对标准偏差（RSD）为2.55%～6.87%。应用该方法对市售合成革产品进行监测,结果在1个样品中检出了异佛尔酮二异氰酸酯。该方法定性准确,定量限低,灵敏度高,可用于合成革中异氰酸酯残留的测定。     

Effect of the soft and hard segment composition on the properties of waterborne polyurethane-based solid polymer electrolyte for lithium ion batteries

Journal of Solid State Electrochemistry - A series of waterborne polyurethane (WPU) with various hard segment and soft segment content were synthesized by hexamethylene diisocyanate (HDI),...     

t-ZrO2/α-Al2O3超细晶复合粉体的低温燃烧合成

以Al(NO3)3*9H2O、ZrO(NO3)2*2H2O和Y(NO3)3*6H2O为原料,采用低温燃烧合成(LCS)法制备了多种不同ZrO2/Al2O3比的复合粉体,对其物相和形貌进行了表征.实验结果表明,采用LCS法在400℃合成的t-ZrO2/α-Al2O3复合粉体晶粒超细,其结晶程度随ZrO2/Al2O3比的增加逐渐降低,晶粒大小也随ZrO2/Al2O3比的变化而有规律地变化.     

Fabrication and characterization of Ni-SSZ/SSZ/LSM-SSZ anode-supported SOFCs by tape casting and single-step co-sintering techniques

In this work, Ni-10 % Sc₂O₃-stabilized ZrO₂ (SSZ)/SSZ/La_0.8Sr_0.2MnO_3-δ (LSM)-SSZ anode-supported solid oxide fuel cells (SOFCs) have been successfully prepared by tape casting and single-step co-sintering procedures. The structure contains Ni-SSZ anode substrate and Ni-SSZ anode functional, dense SSZ electrolyte, LSM-SSZ cathode functional, and LSM-SSZ cathode layers were successfully prepared at 1250, 1300, and 1350 °C, respectively. The microstructures of the single cells were examined by SEM. There were some close pores in electrolyte of Cell-1250, and the cathode particle size obviously increased in Cell-1350. Therefore, Cell-1300 showed the optimal cell performance, the maximum power density attained 920 mW cm^?2 at 800 °C. The impedance analysis demonstrated that the co-sintered temperatures have effects on not only the polarization resistance R _P of a single cell but also its overall ohmic resistance R _S . The results indicate that the tape casting and single-step co-sintering methods are both time saving and feasible for the development of anode-supported SOFCs.     

High lithiophilic nitrogen-doped carbon nanotube arrays prepared by in-situ catalyze for lithium metal anode

Lithium metal has a very outstanding theoretical capacity(3860 mAh/g) and is one of the most superior anode materials for high energy density batteries.However,the uncontrollable dendrite growth and the fo rmation of "dead lithium" are the important hidden dangers of short cycle life and low safety.However,the uncontrollable dendrite growth and the fo rmation of dead lithium leads to short cycle life and hidden dange r,which hinder its practical application.Controlling the nucleation and growth process of lithium is an effective strategy to inhibit lithium dendrite.Herein,a simple in situ self-catalytic method is used to construct nitrogen doped carbon nanotube arrays on stainless steel mesh(N-CNT@SS) as a lithium composite anode.The N-doped CNTs provide a great number of N-functional groups,which enhance the lithiophilic of anode and provide a large number of uniform nucleation sites,hence it has excellent structural stability for cycles.The arrays provide neat lithium-ion transport channels to uniform lithiumion flux and inhibits dendrite generation,revealed by the COMSOL multi-physics concentration field simulation.The N-CNT@SS composite anode sustain stable at 98.9% over 300 cycles at 1 mA/cm2.NCNT@SS as the anode is coupled LiFePO_4(LFP) as the cathode construct a full battery,demonstrating excellent cycling stability with a capacity of 152.33 mAh/g and capacity retaining ratio of 95.4% after 100 cycles at 0.5 C.     

锂离子电池3d 过渡金属氧化物负极微/纳米材料

与传统的碳材料相比,锂离子电池3d 过渡金属氧化物(M_xO_y,M = Co、Fe、Cu、Ni) 负极材料具有更高的容量、倍率及安全性能,更适于锂离子电池在移动电子设备、电动汽车、备用储能和智能电网等领域的应用,因此备受关注。本文介绍了M_xO_y 负极材料的充放电机理,并以零维、一维、二维、三维等纳米结构及空心、核壳等多种微/纳米结构为出发点,详细讨论了过渡金属氧化物电极材料的电化学性能与结构特征之间的关系,分析了具有不同结构特征的负极材料的合成方法;展望了3d 过渡金属氧化物负极微/纳米材料的研究趋势和发展前景。     

Selective Transportation of Microdroplets Assisted by a Superhydrophobic Surface with pH‐Responsive Adhesion

We report a new strategy to realize the selective transportation of microdroplets assisted by a superhydrophobic surface with pH‐responsive adhesion. On the surface, only basic microdroplets can be pinned and acidic or neutral microdroplets can easily roll off. Therefore, by using the surface as a “mechanical hand”, microdroplets can be transported selectively according to one’s requirements by simply controlling the pH of the solution. The special ability of the surface to achieve selective transportation is ascribed to the following two reasons: 1) superhydrophobicity, which can avoid the wetting problem, and 2) pH‐responsive adhesion, which results from the combined effect of chemical variation of the carboxylic acid group and microstructures on the surface. Furthermore, we also demonstrated a process of selective transportation of microdroplets for applications in droplet‐based microreactors through our surface. The results reported herein advance a new method to realize the selective transportation of microdroplets and we believe that this method could potentially be used in a wide range of applications, such as biomolecular detection and transportation in biochips.     

High rate performance of Li[Ni1/3Co1/3Mn1/3]O2 synthesized via co-precipitation method by different precipitators

In the present study, we investigated the effect of three different precipitators (NaOH, Na₂CO₃ and (NH₄)₂CO₃) on the synthesized layered Li[Ni_1/3Co_1/3Mn_1/3]O₂ cathode materials via co-precipitation method. The obtained compounds were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and galvanostatic charge–discharge measurements. The XRD patterns analysis showed that all the resulted Li[Ni_1/3Co_1/3Mn_1/3]O₂ materials possess a layered hexagonal structure. It was found that at high discharge rate (2C), the prepared Li[Ni_1/3Co_1/3Mn_1/3]O₂ system using Na₂CO₃ as the precipitator exhibits better cycling performance in the charge–discharge tests compared to others, indicating that Na₂CO₃ is an optimum precipitator. After 100 cycles at 2C discharge rate in the voltage range from 2.8 to 4.5 vs. Li/Li⁺, the Li[Ni_1/3Co_1/3Mn_1/3]O₂ system using Na₂CO₃ as the precipitator retains 97% of its initial discharge capacity.     

微波辅助萃取-气相色谱/串联质谱法快速测定纺织品中禁用有机磷阻燃剂

以丙酮为萃取溶剂,采用微波辅助萃取技术对纺织品中禁用有机磷阻燃剂进行萃取,萃取液进行气相色谱/串联质谱测定,从而建立了一种微波萃取-气相色谱/串联质谱分析方法,对纺织品中禁用有机磷阻燃剂进行了测定。6种禁用有机磷阻燃剂三-(1-氮杂环丙烯基)氧化膦(TEPA)、三-(2-氯乙基)磷酸酯(TCEP)、三-(2,3-二氯丙基)磷酸酯(TDCP)、二-(2,3-二溴丙基)磷酸酯(DDBPP)、三-(邻甲苯基)磷酸酯(TOCP)和三-(2,3-二溴丙基)磷酸酯(TRIS)的线性范围分别为9.17~366.80、0.95~75.98、1.04~83.20、41.60~832.00、3.80~75.90、40.48~809.60 ?g/L,在S/N=10的条件下,检出限分别为3.0、0.2、0.3、25.0、2.5、29.0 ?g/kg。方法精密度为3.80~8.79 %,回收率为82.62~96.88 %。气相色谱/串联质谱母离子和子离子一一对应的多反应监测模式有效地去除了基体杂质干扰和假阳性现象。该方法简便快速、灵敏度高,定性准确,可完全满足纺织品中禁用有机磷阻燃剂的检测要求。     

SnS2/SnO2 Heterostructures towards Enhanced Electrochemical Performance of Lithium–Sulfur Batteries

Lithium–sulfur (Li–S) batteries have been recognized as outstanding candidates for energy storage systems due to their superiority in terms of energy density. To meet the requirements for practical use, it is necessary to develop an effective method to realize Li–S batteries with high sulfur utilization and cycle stability. Here, a strategy to construct heterostructure composites as cathodes for high performance Li–S batteries is presented. Taking the SnS₂/SnO₂ couple as an example, SnS₂/SnO₂ nanosheet heterostructures on carbon nanofibers (CNFs), named C@SnS₂/SnO₂, were designed and synthesized. Considering the electrochemical performance of SnS₂/SnO₂ heterostructures, it is interesting to note that the existence of heterointerfaces could efficiently improve lithium ion diffusion rate so as to accelerate the redox reaction significantly, thus leading to the enhanced sulfur utilization and more excellent rate performance. Benefiting from the unique structure and heterointerfaces of C@SnS₂/SnO₂ materials, the battery exhibited excellent cyclic stability and high sulfur utilization. This work may provide a powerful strategy for guiding the design of sulfur hosts from selecting the material composition to constructing of microstructure.