Redox active polymer metal chelates for use in flexible symmetrical supercapacitors:Cobalt-containing poly(acrylic acid)polymer electrolytes

The novel polymer metal chelate electrolytes(polychelates)were prepared by incorporation of cobalt sulfate(Co)into poly(acrylic acid)(PAA)host matrix.Quasi-solid state supercapacitor devices were fabricated using polychelates,PAA-Co X(X:3,5,7,and 10)where X represents the doping fraction(w/w)of Co in PAA.All polymer metal electrolytes were showed excellent bending-stretching properties,thermal stability and electrochemical durability with an optimum ionic conductivity of 3.15×10^(-4) S cm^(-1).Hierarchically porous activated carbon and nano-sized conductive carbon were used to form carbon composite symmetrical device electrodes.The electric double-layer capacitor(EDLC)and redox reactions of Co-incorporated polychelates at the interfaces of porous activated carbon provided an optimum specific capacitance of 341.33 F g^(-1) with a device of PAA-Co7,which is at least 15 times enhancement compared to the device of pristine PAA.The PAA-Co7 device also provided energy density of 21.25 Wh kg^(-1) at a power density of 117.69 W kg^(-1).A prolonged cyclic stability of the device exhibited superior capacitive performance after 10,000 charge-discharge cycles and the maintained 90%of its initial performance.In addition,the supercapacitor with a dimension of 1.5 cm×3 cm containing PAA-Co7 successfully operated the red-blue-green(RGB)LED light.

SYNTHESIS OF SOLUBLE POLY(3,4-DIHYDROXY-o-TOLYLENE):REDOX POLYMER

Conventional chloromethylation, paraformaldehyde/hydrogen chloride in acetic acid medium, was applied to 1,2- dimethoxybenzene. Chloroform-soluble poly（3,4-dimethoxy-o-tolylene） was obtained with an intrinsic viscosity of 0.034 dL g^-1. The polymer was evaluated as a condensation redox polymer precursor formed by a Friedel-Crafts reaction. Cleavage of the methoxy groups present in this polymer resulted in poly（3,4-dihydroxy-o-tolylene） which manifested a great air-oxidation resistance. The redox property of the latter polymer was found to be 1017 mV by potentiometric titration with 0.05 N ceric ammonium nitrate at 25℃. This midpotential was compared to that of catechol, a monomeric analogue, under the same titration conditions.

Hybrid polymer electrolyte for Li–O_2 batteries

Li–O_2 batteries have attracted much attention because of their high specific energy. However, safety problem generated mainly from the flammable organic liquid electrolytes have hindered the commercial use of Li–O_2 batteries. One of the competitive alternatives is polymer electrolytes due to their flexibility and non-flammable property. Moreover, the hybrid polymer electrolyte with enhanced electrochemical properties would be achieved by incorporating inorganic filler, liquid plasticizer and redox mediator into the polymer. While most researches of the hybrid polymer electrolyte focused on Li-ion batteries, few of them took account into its application in Li–O_2 batteries. In this review, we mainly discuss hybrid polymer electrolytes for Li–O_2 batteries with different composition. The critical issues including conductivity and stability of electrolytes are also discussed in detail. Our review provides some insights of hybrid polymer electrolytes for Li–O_2 batteries and offers necessary guidelines for designing the suitable hybrid polymer electrolyte for Li–O_2 batteries as well.

VINYL RADICAL POLYMERIZATION INITIATED WITH CERIC ION AND ETHYL N, N-DIETHYLDITHIOCARBAMYL ACETATE SYSTEM

Acrylamide polymerization initiated with a redox initiation system consisting of eerie ion and ethyl N,N-diethyldithiocarbamyl acetate (EDCA) has been studied. It was found that the polymerization rate equation is in good agreement with that of a redox initiated polymerization, and the overall activation energy of the polymerization was determined to be 25.2 kJ.mol(-1). Accordingly, the system belongs to a redox initiator. The initiation mechanism was proposed based on the end group analysis using FT-IR, UV spectroscopies. Analysis results revealed that the N, N-diethyldithiocarbamyl radical produced from the redox reaction of EDCA with eerie ion can initiate acrylonitrile (AN) polymerization and form the end group on PAN. The resulting PAN was photopolymerized with butyl acrylate (BE) to form PAN-b-PBA block copolymer.

Osmium-Polymer Modified Carbon Nanotube Paste Electrode for Detection of Sucrose and Fructose

The aim of the work was the modification of a carbon nanotube paste electrode with a highly original osmium-polymer hydrogel for the development of a new amperometric biosensor for detection of sucrose and fructose. The biosensor for sucrose is based on the activity of the enzymes invertase and fructose dehydrogenase (FDH) immobilized into a carbon nanotube paste (CNTP) electrode properly modified with the Os-polymer. A second biosensor, for fructose only, is constructed containing inactive invertase and used for detection of fructose and for signal subtraction. The biosensors exhibit a detection limit for sucrose of 2 mM and for fructose of 1 mM, linearity up to 5 mM for both biosensors, high sensitivity (1.98 mA·cm-2·mM for sucrose and 1.95 mA·cm-2·mM for fructose), a good reproducibility (RSD = 2.5% for sucrose and 2.1% for fructose), fast response time (8 s for sucrose and 4 s for fructose) and a stability of about 4 months for both biosensors when stored under wet conditions at 4°C. Finally, the biosensors were applied for specific determination of sucrose and fructose in several commercial fruit juice samples and validated with a commercial spectrophotometric enzymatic kit.

Temporally Separated CO_(2) Photoreduction and H_(2)O Photooxidation over Redox-Active Conjugated Organic Polymer Films

Photocatalytic CO_(2) reduction with H_(2)O of chemicals without H2 generation is interesting but challenging.Herein,we report temporally separated CO_(2) photoreduction and H_(2)O photooxidation that are achieved over redox-active o-hydroxyazo-based conjugated organic polymer films(HAzo-COPFs),affording CO with high efficiency as the sole reduction product.HAzo-COPFs are prepared via interfacial diazo-coupling reactions of aromatic diamines and diphenols,and HAzo-COPF-1 from 4,4′-biphenol and benzidine shows the best performance with a CO generation rate of 53.6μmol g−1 h−1 under visible-light irradiation(>420 nm).Interestingly,we discovered that diphenol(DP-OH)moieties in HAzo-COPFs,serving as electron and proton donors to participate in CO_(2) photoreduction,are oxidized into quinone(DP=O)moieties,which are subsequently photoreduced to regenerate DP-OH in H_(2)O photooxidation.Consequently,CO_(2) photoreduction and H_(2)O photooxidation are temporally separated and perfectly coupled via redox transformation between DP-OH and DP=O that form in situ,affording enhanced charge carrier separation and inhibiting the hydrogen evolution reaction.This work provides new insights for the design of COP photocatalysts and artificial photosynthesis.

Reversible faradaic reactions involving redox mediators and oxygen-containing groups on carbon fiber electrode for high-performance flexible fibrous supercapacitors

Flexible fibrous supercapacitors(FFS)are taking account of as the energy storage devices for wearable electronics owing to their high power density,high safety,long cycle life,and simple manufacturing process.Nevertheless,FFSs have the disadvantage of low specific capacitance that results from the electrochemical characteristics of the electrical double layer on the carbon fiber electrode.In this study,for the first time,an FFS comprising surface-activated carbon fibers as an electrode/current collector and a redox additive gel polymer electrolyte(FFS-SARE)was fabricated for use as a wearable energy storage device.The FFS-SARE showed outstanding electrochemical performance,namely,high specific capacitances of 891 and 399 mF cm^(-2) at current densities of 70.0 and 400 μA cm^(-2),respectively,and remarkable ultrafast cycling stability over 5000 cycles with 92%capacitance retention at a current density of 400.0 μA cm^(-2).Moreover,they exhibited mechanical flexibility and had high feasibility,and they showed good energy storage performance that renders them suitable for use in wearable electronic textiles.

Amperometric Biosensors Sensitive to Organic Peroxides Based on Immobilization of Redox Organic Dyes and Horseradish Peroxidase in Polyester Ionomer Film

Simple and effective organic biosensors sensitive to organic peroxides such as 2 butanone per oxide and tertbutyl hydroperoxide are constructed by immobilizing a series of redox organic dyes and horseradish peroxidase in Eastman AQ polymer film. The organic dyes are methylene blue, methylene green, meldola blue, new methylene blue N and N methyl phenazine methosulphate. The biosensors display high sensitivity and fast response to tertbutyl hydroperoxide and 2 butanone peroxide because of high efficiency of electron transfer between immobilized horseradish peroxidase and the electrode via the redox organic dyes. The comparison of the biosensors employing different organic dyes is made in formal potential, linear range and response time.

Improving the True Cycling of Redox Mediators-assisted Li-O_(2) Batteries

The application of redox mediators has been considered as a promising strategy to boost the performance of aprotic Li-O_(2)batteries.However,the issues brought with redox mediators,especially on the Li anode side have been overlooked.Here,we propose a facile approach of preparing a gel polymer membrane that not only allow uniform Li plating/stripping withlarge current densities over extended cycling but also inhibit the diffusion of redox mediators and avoid redox shuttling,self-discharge,and internal shortcircuiting.More importantly,the gel polymer membrane prevents the penetration of O_(2)and superoxide intermediates from the Li anode.Therefore,it ensures the successful application of both lithium anode and redox mediators in Li-O_(2)batteries to achieve the desired high capacity and rate performance.Meanwhile,it helps understand the benefit and problems of added redox mediators and reactive oxygen species so that theperformance of such Li-O_(2)batteries can be truly evaluated.

聚合物半导体光催化合成过氧化氢:光氧化还原中心的空间分离和协同利用

以地表丰富的水和/或氧气为原料,以太阳能为能量来源的光催化合成过氧化氢是面向碳中和的一个颇具吸引力的路径。近年来,以能带、活性位点、组成等可调的聚合物半导体为光催化剂,开展光合成过氧化氢的研究进入了新的高峰期。当前,该研究主要面临两大关键挑战:1)由于材料性质固有的限制,光氧化还原中心通常难以分离,导致光生电荷复合严重,使得光催化合成过氧化氢的活性较差;2)氧化还原中心的利用率低,多数情况下,只有氧化端或还原端参与过氧化氢的合成,另一侧则与牺牲剂反应消耗。对此,本文聚焦光氧化还原中心的空间分离和协同利用来阐述聚合物半导体光催化合成过氧化氢的最新进展。光氧化还原中心空间分离的关键是在聚合物中设计电子给体和供体单元,例如在聚合物框架中引入原子级金属,构建金属-有机给吸电子体系,或构建全有机给吸电子体系。根据氧化还原中心的光催化行为,协同利用主要分为以下三种模型:1)氧还原耦合有机分子氧化;2)水氧化耦合有机分子还原,3)氧还原耦合水氧化。在此基础上,本文详细探讨了针对上述两个关键挑战的调控模式、特性、催化机制和反应途径。最后,我们阐述了光催化合成过氧化氢的潜在应用,并展望了光催化合成过氧化氢中理性设计氧化还原中心协同利用模式的机遇和挑战。

A New Method for Synthesizing Hyperbranched Polymers with Reductive Groups Using Redox/RAFT/SCVP

The novel hyperbranced polymers containing reductive groups were successfully prepared and characterized using redox/reversible addition fragmentation chain transfer （RAFT）/self-condensing vinyl polymerization （SCVP） method. Several redox initiating chemicals such as Cu（III）/--CONH2, Ce（IV）/--CONH2 and Ce（IV）/--OH were chosen to increase the free radical generating rate, and the chain transfer agent （CTA） was used to reduce the molecular chain propagating rate, in order to obtain polymers with high degree of branching. Detailed analyses based on the molecular weight, α value and the degree of branching of polymers （DB） obtained from 1H-NMR spectra and multi detector size exclusion chromatography （MDSEC） suggested the acquiring of hyperbranced polyacrylamides with Cu（III）/--CONH2 and Ce（IV）/--CONH2 as initiator in the presence of the CTA. Meanwhile, the as-prepared poly（N-hydroxymethyl acrylamide） （PNHAM） with higher DB value （0.48） proved that using Ce（IV）/--OH as the initiator could increase the free radical generating rate and diminish the gap between the propagating rate and the initiation rate during the reaction procedure. In addition, the effect of oxidant concentration on the Mark-Houwink index （α） value and the DB was also studied.

面向水系有机液流电池的离子交换膜

离子交换膜是水系有机液流电池的核心部件,其对离子的快速、选择性传导是水系有机液流电池实现高能量效率、低容量衰减速率的关键.而离子的传导过程与膜内的微观结构密切相关,因此本文结合膜内离子传导通道的构筑策略分析,综述微相分离膜、自具微孔膜、微孔框架膜在水系有机液流电池中的发展;并围绕离子交换膜的离子传导性、电活性分子阻隔性、稳定性和兼容性等重要特性,探讨离子交换膜设计及优化方向,以期为水系有机液流电池专用离子交换膜的创制提供参考.

靶向吸附-转化水中新污染物的研究进展

新污染物(Emerging Contaminants,ECs)具有结构稳定且浓度低的特点,传统污水处理工艺难以完全去除,这对水生态环境和人类健康构成潜在威胁。高级氧化技术(Advanced Oxidation Process,AOPs)可以快速有效地降解持久性污染物,但对于真实水体环境中的微量ECs,AOPs需要过量的氧化剂或消耗更多的能源,使水处理成本大幅提升,甚至导致二次污染。因此,开发高效且低能耗的选择性氧化工艺对处理水中ECs具有现实意义。靶向吸附-转化技术能够有效提高自由基的利用率,高效去除微量、难降解新污染物。本文首先系统性地阐述了水清洁技术中选择性氧化策略的理念,着重介绍了电吸附-转化高效能选择性去除复杂水体中全氟和多氟烷基物质(Per-and Polyfluoroalkyl Substances,PFAS)的技术特点与发展现状,最后对未来的研究方向与趋势进行了展望。

Dual-function redox mediator enhanced lithium-oxygen battery based on polymer electrolyte

The polymer electrolyte based lithium-oxygen battery has showed higher safety than that of organic liquid electrolyte.However,the energy efficiency and cycling stability are still the challenges for the practical application of lithium-oxygen battery.Herein,the 1,4 para benzoquinone has been demonstrated as dual-function redox mediator for promoting both oxygen reduction and oxygen evolution reactions of lithium-oxygen battery with polymer electrolyte,which have been confirmed by the Cyclic Voltammetry and discharge/charge test of battery under O_(2) gas,as well as the theoretical calculations.Furthermore,the composite cathode that in-situ constructed by polymerizing electrolyte precursors with redox me-diator can be beneficial for the electrochemical reactions.Combing composite cathode and lithium ions source,the polymer electrolyte based lithium-oxygen batteries can operate for long lifetime with low charge potentials and good rate performances.Thus,this work has highlighted the promising implementation of lithium-oxygen battery based on polymer electrolyte,in which the dual-function redox mediator are employed for both discharge and recharge processes.

基于氧化还原聚合物固定双酶的谷氨酸传感器的研究

在塑料基片上制备了金薄膜的两电极系统的生物传感器。集成化的Ag｜AgCl参比电极采用丝网印刷在薄膜电极上。以聚乙二醇二缩水甘油醚（PEGDGE）为交联剂，将辣根过氧化酶（HRP）和谷氨酸氧化酶（GLOD）固定到聚乙烯吡啶与2，2＇-双吡啶锇形成的氧化还原复合物中，滴在电极表面形成传感器的工作电极。实验结果表明，该生物传感器在谷氨酸溶液的浓度为1．0×10^-6～4．0×10^-4moL／L的范围内，具有很好的线性关系（r=0．9998，n=9），灵敏度为37．5mA（moL／L）^-1cm^-2；谷氨酸检出限为1.0×10^-6mol／L；传感器响应时间为10s且有良好的一致性和稳定性，使用一个月后仍能保持其初始活性的90％。该传感器可以用于食品工业中的谷氨酸的快速检测和在线监测等。

硅胶修饰-表面分子印迹牛血红蛋白及其识别性能的研究

选用马来酸酐修饰的硅胶作为载体,丙烯酰胺为功能单体,N,N'-亚甲基双丙烯酰胺为交联剂,牛血红蛋白为模板分子,采用氧化还原悬浮聚合法,合成了具有选择性识别的牛血红蛋白分子印迹聚合物.并用红外光谱(IR)、扫描电子显微镜(SEM)和元素分析对聚合物进行了表征,结果表明载体表面成功地接枝了分子印迹聚合物薄层.同时选择性吸附实验表明分子印迹聚合物具有良好的识别性能,能实现水溶液中牛血红蛋白的富集.

氧化还原敏感型胶束的构建和药物控释性能

采用3,3'-二硫代二丙酸、乙酰氯、N-Boc-乙醇胺、ε-己内酯、聚乙二醇单甲醚等为原料,通过分子内脱水、酰化、开环聚合、缩合等一系列反应制备了以聚乙二醇单甲醚(mPEG)为亲水端,聚己内酯(PCL)为疏水端,中间含有二硫键链接的两亲聚合物——mPEG-SS-PCL。通过核磁共振氢谱、傅里叶变换红外光谱对聚合物的结构进行表征;以阿霉素(DOX)为模型药物,探讨胶束载药性能和氧化还原敏感性能。并通过MTT法评价了聚合物的细胞毒性。研究结果表明,mPEGSS-PCL可自组装形成胶束,该胶束粒径分部均匀,外表圆整,粒径约为190 nm,其结构具有良好的氧化还原敏感性;胶束的载药量为10. 0%,载药稳定性良好,且具有显著的药物控制释放性;此外,胶束在细胞水平表现为良好的生物安全性。

酶生物燃料电池

综述了酶生物燃料电池的研究进展,特别是近年来在电池结构、性能以及电池的正极和负极研究等方面的成果。详细介绍了酶燃料电池中酶电极的制备方法和用于酶电极修饰材料的研究现状,对酶燃料电池研究中需要解决的问题和发展方向进行了探讨。

锇聚合物修饰的低浓度葡萄糖传感器制备与响应特性研究

将锇氧化还原聚合物与辣根过氧化酶共价交联修饰薄膜金电极,使用戊二醛交联固定葡萄糖氧化酶制得葡萄糖传感器,对传感器的制备条件和其对低浓度葡萄糖的响应特性进行了研究。在-0.1V(vs.Ag|AgCl)电位下,该传感器的背景电流小于1nA,检出限为1μM,小于400μM范围内灵敏度为2900nAμM-1(相关系数R=0.998),且能够消除抗坏血酸对葡萄糖测定的干扰,实现了低浓度葡萄糖的测定,为实现血糖的无创监测奠定了基础。

一种新型氧化还原活性凝胶电解质在超级电容器中的应用

以2-巯基吡啶(PySH)为氧化还原活性介质,以聚乙烯醇(PVA)为聚合物基体,采用溶液共混法制备了PVA-H2SO4-PySH凝胶电解质,研究了PySH添加量对凝胶电解质离子电导率的影响,并组装了活性炭电极超级电容器,利用循环伏安、恒流充放电、交流阻抗谱和自放电等测试对超级电容器电化学性能进行了表征。结果表明,PySH的引入提高了凝胶电解质的离子电导率,同时也改善了超级电容器的电化学性能,在相同电流密度下,超级电容器电极比电容由137F/g提高为394F/g,能量密度由3.6Wh/kg提高到12.4Wh/kg,经过3000次充放电循环后比电容保持率为89%。