滴定-凝胶法制备球形水凝胶吸附材料及其在废水处理中的应用

滴定-凝胶法制备球形水凝胶吸附材料具有3D倒漏斗状微观形貌结构，孔径分布宽泛，对水体中重金属、染料等污染物具有快速响应机制，已被广泛用于水处理过程研究。综述了滴制法制备球形水凝胶吸附材料的主要过程机理、水凝胶具有的特殊形貌结构及其在水处理过程中的应用，分析了球形水凝胶吸附材料在水处理应用过程中存在的问题和局限，并指出了其在水处理领域的应用前景及发展方向。     

复合添加剂对钒电池正极电解液性能的影响

为了提高钒电池电解液的性能，选取了3种复合添加剂，研究了复合添加剂对钒电池正极电解液稳定性和电化学性能的影响。利用电化学方法制备了2 mol/L的全钒液流电池正极5价钒离子电解液，采用临界胶束浓度法得到复合添加剂的配比为：1% KHSO₄+3 mmol/L SDBS（十二烷基苯磺酸钠）、1% KHSO₄+2 mmol/L D-山梨醇、1% KHSO₄+2 mmol/L CTAB（十六烷基三甲基溴化铵），并考察添加剂加入电解液后的稳定性与电化学性能。通过XRD分析手段，对电解液沉淀物的成分进行了表征。研究表明：添加剂的加入，并不会引起钒离子价态的变化，1% KHSO₄+2 mmol/L CTAB加入后，电解液峰电位差减小12 mV，峰电流增加9.8 mA，说明CTAB与KHSO₄在合适配比下，能够有效提高正极电解液的稳定性及可逆性，添加剂的引入并未引起电解液沉淀物的物相组成变化，电解液性能显著提高。     

Li-doping stabilized P2-Li0.2Na1.0Mn0.8O2 sodium ion cathode with oxygen redox activity

The discovery of the oxygen chemistry phenomenon reveals bright future toward new sustainable layered Na-based transitional oxides. However, the poor capacity retention problem of the cathode has hindered the development of sodium ion batteries (SIBs). In this work, a new Li-doped compound Li_0.2Na_1.0Mn_0.8O₂ is proposed, which demonstrates refined cycling durability with 51.6% after 100 cycles at 50 mA g⁻¹, superior than Na_1.2Mn_0.8O₂ with only one cycle. Then in situ X-ray diffraction (XRD) and density function theory (DFT) are employed to explore the lattice distortion and confirm stable lattice framework introduced by Li atoms with eliminated P2-O2 phase transition upon cycling, guaranteeing outstanding electrochemically stable performance. In addition, Li_0.2Na_1.0Mn_0.8O₂ demonstrates activation of Mn as well as O chemistry redox in the lattice, detected by ex situ electronic paramagnetic resonance spectroscopy (EPR) as well as in situ Raman, which indicate not only Na-deficient Mn-based layered oxide but also Na-rich Mn-based compound can represent oxygen redox.     

1,2-Dimethylimidazole based bromine complexing agents for vanadium bromine redox flow batteries

To stabilize bromine produced during a vanadium-bromine redox flow batteries (VBr RFBs) charging, a bromine complexing agent (BCA) should be effectively used as a supporting material in VBr electrolyte. However, there remains a problem of improving the unstable reversibility between V²⁺ and V³⁺ in electrolyte including halogen elements (Br and Cl). This paper describes two imidazole-based BCAs, which are 1,2-dimethyl-3-ethylimidazolium bromide (DMEIm: C₇H₁₃BrN₂) and 1,2-dimethyl-3-propylimidazolium bromide (DMPIm: C₈H₁₅BrN₂), for not only confirming the capture of bromine but also improving the redox reaction of vanadium ions in VBr electrolyte. The effectiveness of the proposed two imidazole-based BCAs is demonstrated through the following experiments: cyclic voltammetry (CV), nuclear magnetic resonance analysis (NMR), scanning electron microscopy (SEM) analysis and cyclic cell operation test. Experimental results show that both the diffusion coefficient and the peak currents of each electrolyte using the proposed imidazole-based BCAs increases linearly with the rise of scan rate on the recorded CV curves, providing improved reversible reaction of V²⁺/V³⁺ in negative electrolyte. It also exhibits that the electrolytes using the DMEIm and DMPIm provide significantly improved charge (discharge) capacities which are 9.38 (31.01) % and 11.8 (35.66) % higher than the pristine one, respectively, resulting in 13.27% and 14.36% higher current efficiencies. In addition, corrosion cracks on the separator surface due to bromine attack are not observed after the cyclic cell operation. Consequently, these results indicate that the proposed two imidazole-based BCAs can not only sequester bromine during the VBr RFB charging, but also enhance electrochemical reversibility caused by improving diffusion coefficient of vanadium.     

Microfluidic Tumor-on-a-Chip Model to Study Tumor Metabolic Vulnerability

Tumor-specific metabolic adaptations offer an interesting therapeutic opportunity to selectively destroy cancer cells. However, solid tumors also present gradients of nutrients and waste products across the tumor mass, forcing tumor cells to adapt their metabolism depending on nutrient availability in the surrounding microenvironment. Thus, solid tumors display a heterogenous metabolic phenotype across the tumor mass, which complicates the design of effective therapies that target all the tumor populations present. In this work, we used a microfluidic device to study tumor metabolic vulnerability to several metabolic inhibitors. The microdevice included a central chamber to culture tumor cells in a three-dimensional (3D) matrix, and a lumen in one of the chamber flanks. This design created an asymmetric nutrient distribution across the central chamber, generating gradients of cell viability. The results revealed that tumor cells located in a nutrient-enriched environment showed low to no sensitivity to metabolic inhibitors targeting glycolysis, fatty acid oxidation, or oxidative phosphorylation. Conversely, when cell density inside of the model was increased, compromising nutrient supply, the addition of these metabolic inhibitors disrupted cellular redox balance and led to tumor cell death.     

Anionic Redox Chemistry as a Clue for Understanding the Structural Behavior in Layered Cathode Materials

The anionic redox chemistries of layered cathode materials have been in focus recently due to an intriguing phenomenon that cannot be described by the number of electrons of transition metal ions. However, even though several studies have investigated the anionic redox chemistry of layered materials in terms of the charge compensation, the relationship between the origin of the structural behavior and anionic redox chemistry in layered materials remains poorly understood. In addition, a simultaneous redox process of transition metal ions could occur through the d bands interaction. Here, it is demonstrated that the anionic redox chemistry is associated with the anisotropic structural behavior of the layered cathode materials albeit without providing additional capacities exceeding the theoretical values. These findings will provide a foundation of a new chapter in the understanding of the properties of materials.     

Redox‐Active Polymers Connecting Living Microbial Cells to an Extracellular Electrical Circuit

Microbial electrochemical systems in which metabolic electrons in living microbes have been extracted to or injected from an extracellular electrical circuit have attracted considerable attention as environmentally‐friendly energy conversion systems. Since general microbes cannot exchange electrons with extracellular solids, electron mediators are needed to connect living cells to an extracellular electrode. Although hydrophobic small molecules that can penetrate cell membranes are commonly used as electron mediators, they cannot be dissolved at high concentrations in aqueous media. The use of hydrophobic mediators in combination with small hydrophilic redox molecules can substantially increase the efficiency of the extracellular electron transfer process, but this method has side effects, in some cases, such as cytotoxicity and environmental pollution. In this Review, recently‐developed redox‐active polymers are highlighted as a new type of electron mediator that has less cytotoxicity than many conventional electron mediators. Owing to the design flexibility of polymer structures, important parameters that affect electron transport properties, such as redox potential, the balance of hydrophobicity and hydrophilicity, and electron conductivity, can be systematically regulated.     

Mediated Electrochemistry to Mimic Biology's Oxidative Assembly of Functional Matrices

Biology uses diffusible oxidants to perform functions that range from signaling to matrix assembly, and these oxidation chemistries offer surprising selectivities. Here, it is reported that mediated electrochemistry can access the richness of such oxidation chemistries. Specifically, electrode‐imposed voltage inputs are used to locally generate oxidized mediators that can diffuse into polymer solutions and induce the formation of covalent bonds for the deposition and functionalization of hydrogels at the electrode surface. Depending on the mediator's redox potential (E⁰), it is possible to “gate” the voltage inputs to target specific residues (e.g., thiols or amines) and oxidation chemistries. Further, mediators of varying E⁰ offer different reactivities and thus allow control of reaction‐diffusion rates to modulate the hydrogel's crosslink density and mechanical properties. Importantly, this mediated oxidation can be performed under physiologically relevant conditions to preserve labile biological functionalities (e.g., cell viability and protein function). Finally, it is demonstrated that protein fusion tags can be engineered to have “targetable” amino acid residues that enable protein function to be oxidatively conjugated to electrodeposited hydrogels. In summary, mediated electrochemistry can engage orthogonal oxidation chemistries to create functionalized matrices and thus mediated electrochemistry should add important capabilities to the electrofabrication toolbox.     

Novel branched sulfonated polyimide membrane with remarkable vanadium permeability resistance and proton selectivity for vanadium redox flow battery application

A series of novel branched sulfonated polyimide (bSPI-x) membranes with 8% branched degree are developed for application in vanadium redox flow battery (VRFB). The sulfonation degrees of bSPI-x membranes are precisely regulated for obtaining excellent comprehensive performance. Among all bSPI-x membranes, the bSPI-50 membrane shows strong vanadium permeability resistance, which is as 8 times as that of commercial Nafion 212 membrane. At the same time, the bSPI-50 membrane has remarkable proton selectivity, which is four times as high as that of Nafion 212 membrane. The bSPI-50 membrane possesses slower self-discharge speed than Nafion 212 membrane. Furthermore, the bSPI-50 membrane achieves stable VRFB efficiencies during 200-time charge-discharge cycles at 120–180 mA cm^?2. Simultaneously, the bSPI-50 membrane exhibits excellent capacity retention compared with Nafion 212 membrane. All results imply that the bSPI-50 membrane possesses good application prospect as a promising alternative separator of VRFB.     

德兴铜矿酸碱废水水质分析方法

为了给德兴铜矿酸碱废水治理工艺提供准确的酸性废水的酸度，碱性废水的碱度，TFe和Fe^2 以及CaCO3的浓度数据，进行分析方法的研究和探讨。采用电位洋定法测定酸度碱度，辈我啉比色法测定TFe和Fe^2 ，以及用修列达法（JISK／451）测定尾矿浆碱水中的CaCO3含量。介绍分析方法的改进，分析过程步骤和分析结果。