Solid oxide membrane-assisted electrolytic reduction of Cr_(2)O_(3) in molten CaCl_(2)

Solid oxide membrane-assisted electrolytic reduction of solid Cr_(2)O_(3) to Cr in molten CaCl_(2) was performed using a sintered porous Cr_(2)O_(3) cathode paired with an yttria-stabilized zirconia(YSZ)tube anode containing carbon-saturated liquid copper alloy.Analyses of the reduction mechanism,ion migration behavior,and effects of cathode pellet porosity and particle size on the electrolysis products and reduction rate revealed that the cathode microstructure and electrolytic conditions were key factors influencing the electrolysis process.Optimal results were obtained when the cathode was characterized by high porosity and a small particle size because this combination of features contributed to ion migration.Good electrochemical activation was observed when cathode pellets prepared by 4 MPa molding followed by 2 h of sintering at 1150℃ were applied.The electrode reduction process(Cr^(3+)→Cr^(2+)→Cr)was promoted by high electrode voltages,and Cr metal was efficiently formed.The proposed method appears to be well suited for electrolytic Cr production because it does not require expensive pre-electrolysis techniques or generate harmful by-products.

Quasi-solid electrolyte membranes with percolated metal–organic frameworks for practical lithium-metal batteries

High-energy Li-metal batteries (LMBs) suffer from short cycle life and safety issues due to severe parasitic reactions and dendrite growth of Li metal anode (LMA) in liquid electrolytes [1–3].It is generally believed that replacing liquid electrolytes with solidstate electrolytes (SSEs) would be a feasible approach for practical LMBs [4,5]. Conventional SSEs including ceramic and polymer electrolytes have been studied for decades.

Effect of Hydrogen Reduction of Silver Ions on the Performance and Structure of New Solid Polymer Electrolyte PEI/Pebax2533/AgBF4 Composite Membranes

In this paper, the effect of hydrogen reduction of silver ions on the performance and structure of new solid polymer electrolyte polyetherimide （PEI）/Pebax2533 （Polynylonl2/tetramethylene oxide block copolymer, PA12-PTMO）/AgBF4 composite membranes is investigated. For PEI/Pebax2533/AgBF4 composite membranesprepared with dillerent AgBF4 concentration, the permeances of propylene and ethylene increase with the increase of AgBF4 concentration due to the carrier-facilitated transport, resulting in a high selectivity. But for propyl- ene/propane mixture, the mixed-gas selectivity is lower than its ideal selectivity. The hydrogen reduction strongly influences the membrane performance, which causes the decrease of propylene permeance and the increase of pro-pane permeance. With the increase of hydrogen reduction time, the membranes show a clearly color change from white to brown, yielding a great selectivity loss. The data of X-ray diffraction and FT-IR prove that silver ions are reduced to Ago after hydrogen reduction, and aggregated on the surface of PEI/Pebax2533/AgBF4 composite mem- branes.

Methane Conversion to C_2 Hydrocarbons in Solid State Oxide Electrolyte Membrane Reactor

Provskite-type catalysts, Ln0.6 Sr0.4 FexCo1-x O3 (Ln = Nd,Pr, Gd, Sm, La, 0＜x＜1) and Ln0.8Na0.2CoO3(Ln= La,Gd, Sm) were synthesized, their catalytic properties in the oxidative coupling of methane (OCM) were examined in a fixed-bed reactor. The former group presented higher activity in the OCM, but the main product was carbon dioxide. While the later group showed lower activity but much higher selectivity to C2 hydrocarbons compared with the former. Electrochemical measurements were conducted in a solid oxide membrane reactor with La0.8 Na0.2CoO3 as catalyst. The results showed that methane was oxidized to carbon dioxide and ethane by two parallel reactions. Ethane was oxidized to ethene and carbon dioxide. A fraction of ethene was oxidized deeply to carbon dioxide. The total selectivity to C2 hydrocarbons exceeded 70%. Based on the experimental results, a kinetic model was suggested to describe the reaction results.

Effect of Solid Retention and Hydraulic Retention Times on Membrane Fouling in Membrane Bioreactor

In this bench scale submerged membrane bioreactor, effect of solid retention time and hydraulic retention time on membrane fouling propensity has been studied. This experiment is carried out at different solid retention time of 5, 10, 30, 70 and 98 days; and fouling behavior of membrane bioreactor is investigated. Average effluent quality is found to be 88.14%-94.38%. The experiment with different hydraulic retention is carried for 3 to 4 days and fouling behavior has been investigated. The effluent quality at different hydraulic retention time of 1, 2, 3, 5, 10 and 24 hours has been investigated. This paper aims to search optimal values of solid and hydraulic retention times at which lower fouling and higher organic removal efficiency can be obtained. This study has been mainly focused on operating parameters rather than microbial structure, effect and analysis of activated sludge to membrane fouling.

Progress in the application of polymer fibers in solid electrolytes for lithium metal batteries

Solid state lithium metal batteries(SSLMBs)are considered to be one of the most promising battery systems for achieving high energy density and excellent safety for energy storage in the future.However,current existed solid-state electrolytes(SSEs)are still difficult to meet the practical application requirements of SSLMBs.In this review,based on the analysis of main problems and challenges faced by the development of SSEs,the ingenious application and latest progresses including specific suggestions of various polymer fibers and their membrane products in solving these issues are emphatically reviewed.Firstly,the inherent defects of inorganic and organic electrolytes are pointed out.Then,the application strategies of polymer fibers/fiber membranes in strengthening strength,reducing thickness,enhancing thermal stability,increasing the film formability,improving ion conductivity and optimizing interface stability are discussed in detail from two aspects of improving physical structure properties and electrochemical performances.Finally,the researches and development trends of the intelligent applications of high-performance polymer fibers in SSEs is prospected.This review intends to provide timely and important guidance for the design and development of polymer fiber composite SSEs for SSLMBs.

Transport of Indium, Gallium and Thallium Metal Ions Through Chromatographic Fiber Supported Solid Membrane in Acetylacetone Containing Mixed Solvents

The transport of metal ions of indium, gallium and thallium from source solution to receiving phase through the chromatographic fiber supported solid membrane in the acetylacetone （HAA） containing mixed solvent system has been explored. The fibers supported solid membranes were prepared with chemical synthesis from cellulose fibers and citric acid with the carboxylic acid ion exchange groups introduced. The experimental variables, such as concentration of metal ions （10^-2 to 10^-4 mol.L^-1） in the source solution, mixed solvent composition [for exampl, e, acetylacetone, （2,4-pentanedione）, （HAA） 20% （by volume）, 1,4-dioxane 10% to 60% and HC1 0.25 to 2 mol.L^-1] in the receiving phase and stirring speed （50-130 r.min ） of the bulk source and receiving phase, were explored. The efficiency of mixed solvents for the transport of metal ions from the source to receiving phase through the fiber supported solid membrane was evaluated. The combined ion exchange solvent extraction （CIESE） was observed effective for the selective transport of thallium, indium and gallium metal ions through fiber supported solid membrane in mixed solvents. The oxonium salt formation in the receiving phase enhances thallium, indium and gallium metal ion transport through solid membrane phase. The selective transport of thallium metal ions from source phase was observed from indium and gallium metal ions in the presence of hydrochloric acid in organic solvents in receiving phase. The separation of thallium metal ions from the binary mixtures of Be（II）, Ti（IV）, AI（III） Ca（II）, Mg（II）, K （I）, La（III） and Y（III） was carried out in the mixed solvent system using cellulose fiber supported solid membrane.

Solid-State NMR Spectroscopic Approaches to Investigate Dynamics, Secondary Structure and Topology of Membrane Proteins

Solid-state NMR spectroscopy is routinely used to determine the structural and dynamic properties of both membrane proteins and peptides in phospholipid bilayers [1-26]. From the perspective of the perpetuated lipids, 2H solid-state NMR spectroscopy can be used to probe the effect of embedded proteins on the order and dynamics of the acyl chains of phospholipid bilayers [8-13]. Moreover, 31P solid-state NMR spectroscopy can be used to investigate the interaction of peptides, proteins and drugs with phospholipid head groups [11-14]. The secondary structure of 13C = O site-specific isotopically labeled peptides or proteins inserted into lipid bilayers can be probed utilizing 13C CPMAS solid-state NMR spectroscopy [15-18]. Also, solid-state NMR spectroscopic studies can be utilized to ascertain pertinent informa- tion on the backbone and side-chain dynamics of 2H- and 15N-labeled proteins, respectively, in phospholipid bilayers [19-26]. Finally, specific 15N-labeled amide sites on a protein embedded inside oriented bilayers can be used to probe the alignment of the helices with respect to the bilayer normal [2]. A brief summary of all these solid-state NMR ap- proaches are provided in this minireview.

Elucidation of Abnormal Potential Responses of Cation-Selective Electrodes with Solid-State Membranes to Aqueous Solutions of CuCl2 and CdI2

An empirical solution to abnormal potential responses, showing peaks of emf, of commercial Cu2+- and Cd2+-selective electrodes with solid-state membranes was proposed for aqueous solutions of CuCl2 and CdI2. The two-step processes of Mn+ + Yn? (s: solid phase) MY(s) and MY(s) + 2X? X2MY2?(s) (n = 1, 2) at a test solution/electrode-interface were considered as a model. Here, Mn+, Yn?, and X? refer to a divalent or univalent cation, functional groups of electrode materials, and a halide ion (X? = Cl?, Br?, I?), respectively. By applying electrochemical potentials to these processes at n = 2, we derived an equation. Regression analyses based on the equation reproduced well the plots of emf versus log 2(*[M]t) for the Cd(II) and Cu(II) systems: *[M]t denotes a total concentration of species relevant to M2+ in a bulk of the aqueous solution. Also, we obtained log Ks(CdBr2) = 4.28 ? 0.22, log Ks(CdI2) = 6.98 ? 0.05, log Ks(CuCl2) = 3.96 ? 0.09, and log Ks(CuBr2) = 11.4 at 25?C. The magnitude in ?log Ks reflected that in the logarithmic solubility product, log {*[M2+](*[X?])2}, for bulk water, where *[M2+] or *[X?] denotes a molar concentration of the bulk solu-tion of M2+ or X? at equilibrium, respectively. Moreover, a mixture of CuSO4 with NaCl at the molar ratio of 1:1 yielded a plot similar to that of CuCl2.

Removal of Di-2-Ethyl Hexyl Phthalates by Membrane Bioreactor

A lab scale membrane bioreactor system was built to investigate the removal of Di-2-Ethyl Hexyl Phthalates (DEHP) in wastewater under variation of three runs: two hydraulic retention time (HRT) 24 and 36 hours in addition to two biomass: concentrated and light sludge. Solid phase extraction (SPE) followed by high performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) was applied to quantitatively identify DEHP in wastewater samples. Membrane bioreactor was built and operated to investigate DEHP removal. Higher HRT removed DEHP more efficiently than lower HRT. The concentrated MLSS could achieve higher removal efficiency than the lighter MLSS at the same HRT value. The performance of MBR in removing DEHP, TOC and COD from wastewater with a maximum removal efficiency were 29%, 85%, and 98%, respectively. Mass balance of DEHP in the system indicated that a majority was removed by adsorption process rather than filtration or microbiological process.

SPE Membrane Electrode and Its Application to Chemical Sensor

The structure and proton conducting mechanism of solid polymer electrolyte (SPE) are described. Since the conductivity of electrolyte is important in SPE electrochemical cell research and development, we investigate quantitatively the conductivity of Nafion membrane and its dependence on temperature and relative humidity. Experimental results show that the conductivity of Nafion membrane increases with temperature and relative humidity. We also reports on the preparation and development of SPE membrane electrode with the emphasis on the mixture pressing method and impregnation-reduction process to prepare SPE composite electrode assemblies and their application to electrochemical sensors. We also investigate and fabricate a potentiometric electrochemical sensor of hydrogen and ethylene to measure the hydrogen and ethylene partial pressure.

Treatment of Chinese traditional medicine wastewater in a submerged membrane bioreactor

A pilot scale test was conducted in a submerged membrane bioreactor SMBR with capacity of 10. 0 m^3/d for 120 days to treat high-strength Chinese traditional medicine wastewater. Performance of the SMBR was investigated with a sludge retention time （ TSR ） of 50 days, a hydraulic retention time （ THR ） of 8.0 h, membrane flux of 8. 0 IV（ m^2 · h） and dissolved oxygen （DO） concentration of 2. 0 - 3. 0 mg/L, respectively. It was observed that the SMBR had high capacity of COD and suspended solid （SS） removal. The influent COD concentration was fluctuated between I 000 and 5 000 mg/L, while the averaged effluent COl） concentration was only 44. 6 mg/L. The influent SS concentration was fluctuated between 1 000 and 1 600 mg/L, while little effluent SS was detected. It was found that the COD remove rate increased with mixed liquor suspended solids （MLSS） and organic loading rate （ROL）. In order to obtain good-quality effluent, the operational conditions of the SMBR were suggested as follows： the temperature was controlled above 10 ℃, MLSS about 7000 mg/L, R,L under 24. 76 kg/（ m^3 · d）, low vacuum value and constant water flux.

基于固态电解质膜的软包电池制备与初步表征

固态电池安全性高、可适应高比能正负极,是蓄电池发展的方向,但存在固相界面阻抗大、界面结构稳定性差等问题。为了快速评估固态电池技术在实用型蓄电池中的作用,本文采用流延法制备了在50℃下离子电导率为6.16×10^(-4)S/cm的固态电解质膜。以高镍三元为正极、石墨为负极,制备了质量为1.1214 g、容量为53.44 mAh的微型软包电池和容量为7252.8 mAh的大容量软包电池。微型软包电池实现了5 C高倍率的放电和150次循环,大容量软包电池在放电深度(DOD)为13.78%时,实现了439次循环充放电。以上结果说明固态电解质膜满足在锂离子电池中使用的要求,然而这些电池的界面构筑仍有不足之处。基于本文结果,通过对固态电解质膜材料、电池化成制度等进行改进,有望促进高性能电池的研发。

矿井水直接超滤试验研究

为了解决矿井水处理现有工艺流程长、出水水质不稳定等问题,优化矿井水处理工艺,以河北某矿井水为研究对象,采用直接超滤短流程工艺进行试验研究,探究反洗时长、反洗周期、工作压力等工艺参数对超滤的影响,并筛选膜污染清洗药剂。结果表明:最佳工艺参数为反洗时长120 s,反洗周期60 min,跨膜压差0.25 MPa,在此条件下经过300 min试验测试,膜通量为136 L/(m^(2)·h),维持在初始膜通量的91%,出水浊度稳定在0.05 NTU以下;膜污染最佳清洗药剂为0.2%HCl,对污染前后及酸洗碱洗后的膜片进行SEM和EDS测试分析,结果表明造成酸洗碱洗效果差异的主要因素为矿井水中的硬度离子和铝离子。

PDMS膜渗透浓缩对天然玫瑰冻干露香气的影响

为探究聚二甲基硅氧烷膜渗透汽化技术对玫瑰冻干露浓缩的影响,选取大马士革玫瑰为研究对象,采用顶空固相微萃取和气相色谱-质谱联用法对冻干露挥发性香气成分进行分析,结合感官分析,评价其感官属性和可利用性。结果表明,玫瑰冻干露原液中检测出了54种香气物质,玫瑰特征性香气物质苯乙醇、香茅醇和香叶醇占比超过90%,极具利用价值。经过两次渗透浓缩后,玫瑰香气更加浓郁和典型,苯环类香气物质含量显著提高,表现为玫瑰香气物质的总香气活度值提高20.47%,感官风味剖面分析也有相似的结果,花香的风味强度值占比由37%提升至51%,与偏最小二乘回归验证分析的结果一致。通过感官标度打分法,发现二级渗透玫瑰冻干露的香气强度与市售玫瑰香精相似,100倍稀释后香气强度仍高于市售玫瑰苏打水,具有用于香精日化、饮料增香的潜力。

玉米中赤霉烯酮的快速检测:注射器式膜固相萃取与固相荧光法

利用膜固相萃取结合固相荧光光谱对玉米样品中的赤霉烯酮进行快速检测.利用乙腈/水(体积比为9∶1)对玉米样品中的赤霉烯酮进行提取,随后利用尼龙膜材料(孔径:0.22μm,Φ=13 mm)进行高效固相萃取.随后利用360 nm LED光源及研制的便携式固相荧光检测装置直接对膜材料表面的赤霉烯酮进行快速检测.所研发的快速检测方法检出限为12.5μg/L,对玉米样品进行加标检测的回收率为84.8%~92.2%,相对标准偏差为3.73%~5.47%.本研究对玉米中赤霉烯酮毒素的快速检测提供了新的检测装置和检测方法,具有便携、高效、成本低等诸多优势,能够满足食品领域对玉米样品的现场快速检测需求.

高通量-高截留率时间维度膜法水处理机理研究

传统固液两相流膜分离技术利用尺寸效应易受到渗透性-选择性权衡的制约、膜污染与浓差极化等挑战。通过引入旋转剪切动态膜技术与施加固液滑移边界条件,利用膜表面颗粒径向穿透膜孔的时间大于切向划过孔径的时间——时间维度选择性,可有效同步提升渗透性和选择性。通过建立滑移边界旋转剪切动态膜过滤模型,对稀悬浮液微滤过程进行有限元模拟仿真,并结合理论分析揭示了滑移速度、膜厚度与孔隙率等关键参数对膜分离性能的影响规律。结果表明,对于比颗粒直径大1~10倍的膜孔径,在时间维度选择性与流体剪切诱导颗粒迁移的协同作用下,可获取95%以上的微颗粒截留率和350 L(/m^(2)·h)以上的有效水通量。该研究结果进一步验证并拓展了时间维度选择性机理在微米尺度的适用性,并为高通量-高截留率动态膜法水处理技术提供了新思路。

弹性膜对部分充液罐车内液体晃动的抑制效果研究

为了提高液罐车的制动性能和侧倾稳定性极限,建立了流固耦合模型,研究了弹性膜对部分充液罐车内液体晃荡的抑制效果.进行了实验室实验,实验结果验证了数值模型的有效性.验证后的模型被进一步用于研究不同的弹性膜配置对晃荡响应的影响,如液体载荷传递、晃荡力、俯仰力矩和罐壁压强.研究中考虑了两种不同的储罐配置,即没有任何阻尼装置的储罐和具有各种弹性膜组合的储罐,以进行比较.结果表明,添加弹性膜可以显著限制液体的运动,从而显著降低由晃动引起的俯仰力矩,这将提高罐车的制动性能和侧倾稳定性极限.

ETPTA复合PVDF-HFP基聚合物固态电解质膜的制备与性能研究

固态电池因其优异的性能备受关注,但是与传统的液态电池相比,离子传输能力偏弱,原因是固-固界面离子传输困难。本文制备了以聚偏氟乙烯-六氟丙烯(PVDF-HFP)为基的固态电解质膜,并探究PVDF-HFP和增塑剂乙氧基化三羟甲基丙烷三丙烯酸酯(ETPTA)质量比为1.0∶0.3、1.0∶0.4、1.0∶0.5时对电解质膜离子传输的影响,并组装成以磷酸铁锂为正极、锂片为负极的固态电池,研究其电化学性能。研究发现:当PVDF-HFP和ETPT质量比为1.0∶0.4时,锂离子迁移数达0.89,电化学窗口可达4 V,离子电导率达到8×10^(-5)S/cm,表现出良好的稳定性。将质量比为1.0∶0.4的电解质膜装配成固态电池,经过激活之后,首先在0.1C的倍率下进行测试,首圈充电比容量为133 m A·h/g,首圈放电比容量为129 m A·h/g,在20圈循环测试后,放电比容量也能保持在120 mA·h/g以上,容量保持率为92%。

基于膜式固相萃取的水体全氟化合物检测方法研究

基于膜式固相萃取法和液相色谱-串联质谱法建立了一种高灵敏、快速分析环境水样中痕量全氟化合物(PFASs)的方法。采用最优条件的模式固相萃取进行样品前处理,以乙酸铵水溶液及乙腈为流动相进行梯度洗脱,经Accucore aQ C18色谱柱分离,采用电喷雾离子源、负离子采集模式和质谱多反应监测模式分析,实现了环境水样中17种全氟化合物的快速分析,17种全氟化合物检出限(S/N=3)为0.2~0.3 ng/L。将方法应用于实际环境水样中全氟化合物的分析,加标回收率为87%~95%。研究可为快速、有效地检测环境水样中痕量全氟化合物提供新方法的选择。