MXene: A two-dimensional material in selective water separation via pervaporation

MXene, well-identified as Ti₃C₂T_X, belongs to the family of two-dimensional (2D) materials, which have been currently explored in various applications. Very recently, such materials have been pointed out as potential nanomaterials for advanced solute separations when introduced in membranes, such as ion separation, gas separation, nanofiltration, chiral molecular separation, and solvent separation. This latter separation, generally named Pervaporation (PV), is identified as a highly selective technology for water separations. To date, few pieces of research have been released but providing interesting insights into several solvent (including water) separations. Hence, this brief review aims to analyze and discuss the latest advances for utilizing MXenes for PV membranes. Particular emphasis has been devoted to the relevant outcomes in the field, along with the strategies followed by researchers to tailor membranes. Based on the current findings, the perspectives in the field are also stated.     

Discussion of the protein characterization techniques used in the identification of membrane protein targets corresponding to tumor cell aptamers

Aptamer is an oligonucleotide chain with specific binding ability to protein and other targets,which is widely used in ma ny fields.Because of its ability to screen the premise of unknown targets,it can be used to discover some novel tumor markers,i.e.,membrane proteins that are specifically highly expressed on the surface of tumor cells.Tumor markers can be used in many fields such as early diagnosis and treatment,and a new type of tumor marker proved to be effective can significantly improve the therapeutic effect of such tumors.However,further characterization of newly acquired membrane proteins is essential for their clinical use as tumor markers.This review first briefly introduced the process of obtaining novel tumor markers from nucleic acid aptamers.Next,the commonly used protein characterization methods could be used as a technical means to identify membrane protein targets corresponding to tumor cell aptamers,to clarify the principles,advantages and disadvantages of various means,and to analyze the most suitable situations for various experimental methods.Finally,the outlook was made and the characterization methods that should be used in such experiments were summarized.     

Electrochemical Selective Determination of Uranyl Ions Using PVC Membrane Sensor

A UO₂²⁺‐PVC membrane electrode was constructed using 2‐thenoyltrifluoroacetone as ionophore and its electrochemical response performance was characterized. The effect of membrane composition on the electrode performance was studied and best results were obtained using dioctylsebacate as a mediator and potassium tetrakis(4‐chlorophenyl)borate as anion excluder. The optimized UO₂²⁺‐sensor exhibited a Nernstian response with a slope of 29.5±0.5 mV decade⁻¹ over the concentration range 5.0×10⁻⁷−1.0×10⁻¹ mol L⁻¹ at 25 °C with a detection limit of 3.1×10⁻⁷ mol L⁻¹. The optimized electrode showed very good selectivity towards UO₂²⁺ relative to a wide variety of other cations and fast response time. Surface morphology of the optimized membrane electrode at different stages of its development and use was investigated and discussed. Quantum chemical calculations for geometrical optimization of the ionophore were carried out to investigate the interaction between the ionophore and UO₂²⁺ using DFT B3LYP/6‐31++G(d,p) level of theory and the obtained data confirmed the proposed response mechanism. The developed sensor was successfully applied for UO₂²⁺ selective determination in real water samples and the obtained results were compared to those obtained by spectrophotometric method indicating no significant difference.     

质子交换膜燃料电池零下冷启动研究

在零下启动过程中,质子交换膜燃料电池阴极中氧气还原反应生成的水会在催化剂层内部结冰,因而阻碍氧气传输,覆盖催化剂层反应活性位点,降低电化学活性面积,影响燃料电池发电性能,甚至会导致零下启动失败;同时,结冰/融化循环还会破坏膜电极结构,影响燃料电池寿命。因此,质子交换膜燃料电池零下启动技术的研究对促进燃料电池汽车的推广应用有重要意义。本文针对质子交换膜燃料电池的零下启动过程,从实验研究、机理解释、模型分析及策略开发等角度对文献内容进行了梳理,并对涉及质子交换膜燃料电池零下启动过程的专利技术进行了总结。     

Improved Stabilities of Labeling Probes for the Selective Modification of Endogenous Proteins in Living Cells and In Vivo

To date, various affinity-based protein labeling probes have been developed and applied in biological research to modify endogenous proteins in cell lysates and on the cell surface. However, the reactive groups on the labeling probes are also the cause of probe instability and nonselective labeling in a more complex environment, e. g., intracellular and in vivo. Here, we show that labeling probes composed of a sterically stabilized difluorophenyl pivalate can achieve efficient and selective labeling of endogenous proteins on the cell surface, inside living cells and in vivo. As compared with the existing protein labeling probes, probes with the difluorophenyl pivalate exhibit several advantages, including long-term stability in stock solutions, resistance to enzymatic hydrolysis and can be customized easily with diverse fluorophores and protein ligands. With this probe design, endogenous hypoxia biomarker in living cells and nude mice were successfully labeled and validated by in vivo, ex vivo, and immunohistochemistry imaging.     

微纳米纤维素功能膜在能源与环境领域的应用

探寻绿色清洁的资源与材料以维持高效的社会经济增长是未来数十年人们面临的最大挑战之一. 可持续资源与绿色材料的开发是降低传统化石能源与材料比重的最有前途的方案. 纤维素作为一种可持续发展、 可生物再生、 储量丰富且低成本的天然高分子聚合物, 在众多领域中具有广泛的应用, 并且纤维素可以加工成各种构型, 包括气凝胶、 泡沫、 海绵和薄膜等. 本文介绍了不同形态的纤维素及其衍生物组装而成的功能膜在能源与环境中的应用, 综述了微纳米纤维素及其衍生物在先进功能化储能器件方面的最新进展和制备方案, 以及在用于水处理的膜分离技术中的应用, 其中重点讨论了微纳米纤维素及其衍生物功能膜在电池、 电容器及水处理等领域中的作用, 如隔膜、 柔性电极膜和分离膜等. 此外, 还对纤维素及其衍生物功能膜的未来发展进行了总结和展望.     

分子筛膜反应器的研究进展

分子筛膜具有规整的微孔结构(<1 nm), 耐高温高压、 抗有机溶剂, 在液相和气相小分子分离中受到广泛关注. 分子筛膜可以与催化反应耦合于一体构成膜反应器, 使反应过程与组分分离同时进行, 促进反应平衡移动, 达到反应强化的效果. 本文概述了近十年不同类型分子筛膜反应器在催化反应中的应用研究进展, 并对分子筛膜反应器未来的发展趋势进行了展望.     

Co3O4/UiO-66@α-Al2O3陶瓷膜对VOCs废气的分离催化性能

以α-Al₂O₃为支撑层, UiO-66为分离层, Co₃O₄为催化层, 构建了Co₃O₄/UiO-66@α-Al₂O₃陶瓷膜.对其形貌结构进行了表征, 并研究了其对挥发性有机物(VOCs)的分离催化性能. 结果表明, 该陶瓷膜对喷涂行业废气中苯与吡啶两种主要成分体现出良好的分离性, 透过侧的气体中吡啶与苯的摩尔浓度比值可由给料侧的1提高至17; 体系中引入臭氧后, 给料侧苯的浓度明显降低, 其去除率可达到89%. 透过侧的吡啶去除率仅为27%, 得到了较大程度的保留, 剩余的吡啶经收集后可进行单独的深度处理. Co₃O₄/UiO-66@α-Al₂O₃陶瓷膜在对喷涂行业废气中苯成分高效降解的同时, 能够有效解决喷涂行业废气处理过程中氮氧化物的排放问题, 有望成为喷涂行业废气预处理工艺的理想选择.     

Numerical simulation of effects of flow maldistribution on heat and mass transfer in a PEM fuel cell stack

A 3D numerical study was carried out to analyze flow, heat and mass transfer first in a single half-cell cathode channel of proton exchange membrane (PEM) fuel cell. From practical point of view, it is necessary to put the appropriate number of cells in a stack. Hence, the above study on a single half-cell is extended to a stack of channels. Due to stacking, the assumption of uniform flow distribution would no longer hold true. Therefore, the channel flow-maldistribution is considered. The water formed at the active surface due to the electrochemical reaction diffuses through the porous layer and eventually enters the gas flow duct. The higher gas velocities in the duct result in faster water vapour removal which leads to a lower value of water vapour into the duct and hence a lower Nusselt number.     

A review on pharmaceuticals removal from waters by single and combined biological,membrane filtration and ultrasound systems

Contaminants of emerging concern (CEC) such as pharmaceuticals commonly found in urban and industrial wastewater are a potential threat to human health and have negative environmental impact. Most wastewater treatment plants cannot efficiently remove these compounds and therefore, many pharmaceuticals end up in aquatic ecosystems, inducing problems such as toxicity and antibiotic-resistance. This review reports the extent of pharmaceutical removal by individual processes such as bioreactors, advanced oxidation processes and membrane filtration systems, all of which are not 100% efficient and can lead to the direct discharge of pharmaceuticals into water bodies. Also, the importance of understanding biotransformation of pharmaceutical compounds during biological and ultrasound treatment, and its impact on treatment efficacy will be reviewed. Different combinations of the processes above, either as an integrated configuration or in series, will be discussed in terms of their degradation efficiency and scale-up capabilities. The trace quantities of pharmaceutical compounds in wastewater and scale-up issues of ultrasound highlight the importance of membrane filtration as a concentration and volume reduction treatment step for wastewater, which could subsequently be treated by ultrasound.