Metal-Organic Framework Enabling Poly(Vinylidene Fluoride)-Based Polymer Electrolyte for Dendrite-Free and Long-Lifespan Sodium Metal Batteries

Sodium dentrite formed by uneven plating/stripping can reduce the utilization of active sodium with poor cyclic stability and,more importantly,cause internal short circuit and lead to thermal runaway and fire.Therefore,sodium dendrites and their related problems seriously hinder the practical application of sodium metal batteries(SMBs).Herein,a design concept for the incorporation of metal-organic framework(MOF)in polymer matrix(polyvinylidene fluoride-hexafluoropropylene)is practiced to prepare a novel gel polymer electrolyte(PH@MOF polymer-based electrolyte[GPE])and thus to achieve high-performance SMBs.The addition of the MOF particles can not only reduce the movement hindrance of polymer chains to promote the transfer of Na^(+)but also anchor anions by virtue of their negative charge to reduce polarization during electrochemical reaction.A stable cycling performance with tiny overpotential for over 800 h at a current density of 5 mA cm^(-2)with areal capacity of 5 mA h cm^(-2)is achieved by symmetric cells based on the resulted GPE while the Na_(3)V_(2)O_(2)(PO_(4))_(2)F@rGO(NVOPF)|PH@MOF|Nacell also displays impressive specific cycling capacity(113.3 mA h g^(-1)at 1 C)and rate capability with considerable capacity retention.

Metal organic polymers with dual catalytic sites for oxygen reduction and oxygen evolution reactions

Metal-organic frameworks and covalent organic frameworks have been widely employed in electrochemical catalysis owing to their designable skeletons,controllable porosities,and well-defined catalytic centers.However,the poor chemical stability and low electron conductivity limited their activity,and single-functional sites in these frameworks hindered them to show multifunctional roles in catalytic systems.Herein,we have constructed novel metal organic polymers(Co-HAT-CN and Ni-HAT-CN)with dual catalytic centers(metal-N_(4) and metal-N_(2))to catalyze oxygen reduction reaction(ORR)and oxygen evolution reaction(OER).By using different metal centers,the catalytic activity and selectivity were well-tuned.Among them,Co-HAT-CN catalyzed the ORR in a 4e^(-)pathway,with a half-wave potential of 0.8 V versus RHE,while the Ni-HAT-CN catalyze ORR in a 2e^(-)pathway with H_(2)O_(2) selectivity over 90%.Moreover,the Co-HAT-CN delivered an overpotential of 350 mV at 10 mA cm^(-2) with a corresponding Tafel slope of 24 mV dec^(-1) for OER in a 1.0 M KOH aqueous solution.The experimental results revealed that the activities toward ORR were due to the M-N_(4) sites in the frameworks,and both M-N_(4) and M-N_(2) sites contributed to the OER.This work gives us a new platform to construct bifunctional catalysts.

Two Isostructural 2-D Metal(Ⅱ)-organic Coordination Polymers from 4,4'-Bipyridyl and (E)-2,6-Dimethyl-4-styrylpyridine-3,5-dicarboxylic Acid

（E）-2,6-Dimethyl-4-styrylpyridine-3,5-dicarboxylic acid （H2mspda） is firstly employed in coordination chemistry.Two isostructural two-dimensional （2-D） 4-connected metal-organic coordination polymers with a general formula of {M2[（mspda）2（bpy）（H2O）2]}n （M=Zn（1） and Co（2）） are assembled from H2mspda,4,4＇-bipyridyl （bpy）,zinc and cobalt ions under hydrothermal conditions,and characterized by single-crystal X-ray diffraction analyses.Complex 1 crystallizes in monoclinic,space group P21/n with a=14.551（4）,b=10.941（3）,c=14.945（4）,β=98.817（4）o,V=2351.3（1）3,Dc=1.511 g/cm3,μ（MoKα）=1.090 mm-1,F（000）=1104,Z=4,the final R=0.0335 and wR=0.0485 for 3296 observed reflections （I 〉 2σ（I））.In compound 1,mspda2-spacers are only arrayed in a head-to-tail fashion which corresponds to a 2-D coordination polymer.Solid-state H2mspda and complex 1 have expected photoluminescence （λem=475～496 nm） at room temperature.

Recent Progress on Metal–Organic Framework and Its Derivatives as Novel Fire Retardants to Polymeric Materials

High flammability of polymers has become a major issue which has restricted its applications.Recently,highly crystalline materials and metal–organic frameworks(MOFs),which consisted of metal ions and organic linkers,have been intensively employed as novel fire retardants(FRs)for a variety of polymers(MOF/polymer).The MOFs possessed abundant transition metal species,fire-retardant elements and potential carbon source accompanied with the facile tuning of the structure and property,making MOF,its derivatives and MOF hybrids promising for fire retardancy research.The recent progress and strategies to prepare MOF-based FRs are emphasized and summarized.The fire retardancy mechanisms of MOF/polymer composites are explained,which may guide the future design for efficient MOF-based FRs.Finally,the challenges and prospects related to different MOFbased FRs are also discussed and aim to provide a fast and holistic overview,which is beneficial for researchers to quickly get up to speed with the latest development in this field.

Hydrothermal Synthesis,Structure and Properties of a 3D Pillar-layered Metal-organic Framework Based on Amino-arenedisulfonate Ligand

One novel metal-organic framework(MOF), [Ba(L)(HO)](1, HL =aniline-2,5-disulfonic acid), has been synthesized by hydrothermal method. Each barium atom is eleven-coordinated into a distorted monocapped pentagonal antiprismatic arrangement. Compound 1 shows an interesting 3 D pillar-layered structure constructed from 2 D inorganic layers[Ba(SO)(HO)]and organic pillars of phenyl moieties of L2-linkages. The inorganic layers are supported by the organic pillars, generating a novel 3 D open framework structure with {3, 4~6, 5~5, 6~5,7~4}2{3}{5} topology. The result of fluorescence measurement can reveal that the decayed emission band centered at 492 nm may be caused by the interactions of the ligands and the metal ions.Compound 1 exhibits selective toward the adsorption of COover Nat 273 K.

Metal-organic-framework-derived formation of Co–N-doped carbon materials for efficient oxygen reduction reaction

Non-precious metal nitrogen-doped carbonaceous materials have attracted tremendous attention in the field of electrochemical energy storage and conversion.Herein,we report the designed synthesis of a novel series of Co-N-C nanocomposites and their evaluation of electrochemical properties.Novel yolkshell structured Co nanoparticles@polymer materials are fabricated from the facile coating polymer strategy on the surface of ZIF-67.After calcination in nitrogen atmosphere,the Co–N–C nanocomposites in which cobalt metal nanoparticles are embedded in the highly porous and graphitic carbon matrix are successfully achieved.The cobalt nanoparticles containing cobalt metal crystallites with an oxidized shell and/or smaller(or amorphous)cobalt-oxide deposits appear on the surface of graphitic carbons.The prepared Co–N–C nanoparticles showed favorable electrocatalytic activity for oxygen reduction reactions,which is attributed to its high graphitic degree,large surface area and the large amount existence of Co–N active sites.

Anisotropic self-diffusion of fluorinated poly(methacrylate) in metal-organic frameworks assessed with molecular dynamics simulation

Utilizing the periodically structured metal-organic framework （MOF） as the reaction vessel is a promising technique to achieve the aligned polymer molecular chains, where the diffusion procedure of the polymer monomer inside MOF is one of the key mechanisms. To investigate the diffusion mechanism of fluorinated polymer monomers in MOFs, in this paper the molecular dynamics simulations combined with the density functional theory and the Monte Carlo method are used and the all-atom models of TFMA （trifluoroethyl methacrylate） monomer and two types of MOFs,[Zn2（BDC）2（TED）]n and[Zn2（BPDC）2（TED）]n, are established. The diffusion behaviors of TFMA monomer in these two MOFs are simulated and the main influencing factors are analyzed. The obtained results are as follows. First, the electrostatic interactions between TFMA monomers and MOFs cause the monomers to concentrate in the MOF channel, which slows down the monomer diffusion. Second, the anisotropic shape of the one-dimensional MOF channel leads to different diffusion speeds of monomers in different directions. Third, MOF with a larger pore diameter due to a longer organic ligand,[Zn2（BPDC）2（TED）]n in this paper, facilitates the diffusion of monomers in the MOF channel. Finally, as the number of monomers increases, the self-diffusion coefficient is reduced by the steric effect.

Synthesis and Characterization of a Metal-Organic Framework Bridged by Long Flexible Ligand

3D supramolecular network with considerable volume pores was created via hydrogen bond & C-H--π. By tightening of The metal-organic frameworks (MOF) namely [Ni(μ-pmb)2(H2O)2]n (pmb = 3,5-bis(4-pyridylmethylenoxyl) benzoate, that have been synthesized by hydrothermal method. Complex 1 crystallizes in triclinic P-1 space group and consists of 1D semi zigzag chain.

Preparation of Polymer-Mineral Nanocomposites Based on Vinyl Monomers and Dispersed Inorganic Oxides

The polymer-mineral composites were synthesized using vinyl monomers styrene, methyl acrylate, and butyl acrylate with nano dispersed oxides Fe2O3, Cr2O3, V2O5 and SiO2 in the presence of benzoyl peroxide and other peroxide initiators. Benzoyl peroxide adsorption on Fe2O3, Cr2O3, and V2O5 surfaces was studied. The adsorption parameters were found: adsorption-desorption equilibrium constants, maximum adsorption, and the area occupied by the molecule benzoyl peroxide on the surface of the adsorbent. The molecular weights of the polymers in the composites and the degree of grafting of the macromolecules of the polymer to the surface of oxides were studied. It has been found that the surface of the dispersed oxides influences the rate of thermal decomposition of the peroxide initiators and the polymerization parameters of the vinyl monomers.

Monitoring of Sweat pH and Dual-Mode Anti-Counterfeiting from Metal-Organic Framework-Based Multifunctional Gel

Monitoring of sweat pH plays important roles in physiological health,nutritional balance,psychological stress,and sports performance.However,the combination of functional MOFs with phosphorescent material to acquire the real-time physiological information,as well as the application of dual mode anti-counterfeiting,has seldom been reported.Herein,we developed multifunctional gel films based on MOFs and phosphorescent dyes which responded to H+ions and the related mechanism was studied in detail.Upon exposure to H+,the composite gel film exhibited decreased fluorescent signal but enhanced room temperature phosphorescence(RTP),which could be utilized for sweat pH sensing through a dual-mode.Moreover,multifunctional gel films exhibited a potential application in information encryption and anti-counterfeiting by designing of stimulus responsive multiple patterns.This research provided a new avenue for portable and non-invasive sweat pH monitoring methods while also offering insights into stimulus-responsive multifunctional materials.

聚丙烯催化剂研究进展

综述了聚丙烯(PP)催化剂的研究进展,包括Ziegler-Natta(Z-N)、茂金属、后过渡金属及复合催化剂,重点分析了载体、助催化剂、给电子体对Z-N催化剂活性、结构及性能的影响,并对比了各类催化剂的优缺点。指出今后需在反应机理、合成工艺、聚合物形貌控制等方面对催化剂进行深入研究和设计,在保证催化剂成本的同时,产出性能指标更加优异的PP产品。

新型功能材料在藻毒素萃取中的应用进展

藻毒素为有害藻类所产生的次级代谢产物,具有毒性强、种类多和生物蓄积性等特点,对人类健康、水产养殖业以及水生生态系统都会造成严重的威胁,已成为当前全球范围的研究热点。由于藻毒素在样品中的含量很低、样品基质复杂等因素,在仪器分析前进行有效的样品前处理不可或缺。高效的样品前处理技术不但能够减小或去除样品基质对分析的干扰,而且可以实现目标物的富集,增加分析方法的灵敏度与准确性。近年来,固相萃取(SPE)、固相微萃取(SPME)、磁性固相萃取(MSPE)、分散固相萃取(DSPE)、吸管尖端固相萃取(PT-SPE)等样品前处理技术已在藻毒素分离分析领域广受关注。这些前处理技术性能的好坏主要取决于萃取材料的特性。由于藻毒素的理化特性各不相同,在分子尺寸、亲疏水性、电荷等性质上差异较大,合理设计并制备适合藻毒素萃取的材料十分必要。最佳的萃取材料必须实现对藻毒素的可逆吸附,并且最好具有多孔结构和高的比表面积,从而能够提供高的回收率和与藻毒素良好的界面接触。此外,萃取材料还应该在样品溶液、洗脱溶剂、工作pH范围内具有良好的化学稳定性,否则萃取材料可能会溶解或丢失其官能团。本文综述了近十几年来国内外关于藻毒素分析检测研究的主要代表性文献,对新型功能材料在藻毒素萃取过程中的应用进行了梳理归纳,并对其发展前景予以展望。

基于硼亲和分子印迹策略的MOF/MIPs对沙丁胺醇的选择性吸附和计算模拟

为了探索所构筑的硼酸功能化金属有机框架(MOF)表面印迹材料(FSU-BA@MIP)对底物的亲和识别能力,对FSU-BA@MIP的金属-有机骨架材料(UiO-66-BA)中的3-羧基苯硼酸配体与沙丁胺醇间的硼亲和作用进行计算,再采用密度泛函理论(DFT)对FSU-BA@MIP材料对沙丁胺醇的选择性机理进行模拟,最后进行选择性实验.计算结果表明,离子化的3-羧基苯硼酸与沙丁胺醇间存在的氢键作用使得这两种物质有较强的作用力,更容易形成硼酸环酯;与竞争物质相比,UiO-66-BA与沙丁胺醇的结合能与反应能最低,说明所形成的FSU-BA@MIP印迹材料对底物沙丁胺醇具有特异性吸附.分析结果与实验得到的沙丁胺醇的最高吸附量一致,说明UiO-66-BA是一种可用于分析顺式二醇化合物的理想硼酸功能化材料.

MXene改性导电MOF复合材料及其电磁波吸收性能研究

随着高频通信技术的普及,电磁防护问题受到了广泛关注,基于导电型金属—有机框架(MOF)构建新型电磁波吸收材料近年来成为研究热点。研究提出了MXene改性MOF/聚吡咯(PPy)的制备思路,通过三元组分协同优化介电损耗,成功制备了在低填充量下可实现宽频带、强吸收的高性能吸波材料。当填充量仅为10 wt.%、厚度仅为1.98 mm时,复合材料的最小反射损耗(RLmin)达到了-56.21 dB,最大有效吸收带宽(EAB)可拓展至7.12 GHz(10.88 GHz~18.00 GHz),综合性能优于已报道的导电MOF基吸波材料。通过对材料的组分和微观结构分析,发现过量的PPy不仅原位聚合在UiO-66的孔道和外表面,同时负载在MXene基底上,从而有效构建了导电网络,促进了电导损耗。同时,UiO-66、PPy和MXene构成的三元异质界面极大地增强了界面极化损耗,进一步促进了电磁波的衰减。此外,MXene/UiO-66/PPy制备工艺简单、产量高,具有大规模生产的潜力,有望应用于电磁防护领域。

聚合物基MOFs复合材料抗菌研究进展

金属有机骨架(MOFs)是一类备受瞩目的新兴材料,在抗菌领域有着广泛的应用。将聚合物与MOFs进行复合制备聚合物基MOFs(PolyMOFs)复合材料,不仅可以增强MOFs的稳定性、机械强度等,还可以进一步扩展其应用范围。该文重点综述了PolyMOFs复合材料在抗菌方面的研究进展,概述了功能性MOFs的制备和主要抗菌机制,以及PolyMOFs复合材料的制备方法;总结了具有抗菌功能的PolyMOFs复合材料在医疗健康、食品保鲜、空气净化、水污染防治、纺织品防护领域的应用;最后对具有抗菌功能的PolyMOFs复合材料目前在抗菌领域面临的挑战和未来包括特定功能增强、制备工艺优化和应用领域拓展等方面的发展方向进行了展望。

改性PVDF-HFP基凝胶电解质的合成及锂金属电池性能研究

开发高质量的固态电解质,对制造新一代安全稳定的固态锂金属电池具有重要意义。以聚偏氟乙烯–六氟丙烯(polyvinylidene fluoride-hexafluoropropylene,PVDF-HFP)为聚合物基体,引入MOF-808作为活性填料,采用溶液浇筑法制备了新型凝胶聚合物电解质。优化后的凝胶聚合物电解质在室温下的离子电导率高达3.21 mS/cm,电化学稳定窗口可达5.0 V、具有较高的Li^(+)迁移数(0.63)、与锂金属具有良好的界面相容性。组装的磷酸铁锂全电池在0.5 C倍率下循环250次,容量保持率为86.7%。高性能凝胶聚合物电解质对提升锂金属电池的循环稳定性与安全性具有重要的应用价值。

铅锌冶炼渣基胶凝材料固化电镀污泥研究

电镀污泥是含有各类重金属的危险废物。本文利用铅锌冶炼渣制备胶凝材料,评估该胶凝材料对固化电镀污泥效果,并阐明了有机聚合物对固化过程的影响机制。结果表明,在碱含量为3.5%(质量分数)、水玻璃模数1.4、液固比0.22条件下,铅锌冶炼渣基胶凝材料可安全固化2.5%(质量分数)的电镀污泥;与未加有机聚合物相比,加入有机聚合物后复合胶凝材料对电镀污泥的固化量提高一倍,同时抗压强度提高27.45%,此时总Cr浸出浓度从20.05 mg/L降低至13.65 mg/L,低于《危险废物鉴别标准浸出毒性鉴别》(GB 5085.3—2007)规定的限值。固化体的矿物组成、微观形貌、化学键和原子价态分析表明,在铅锌冶炼渣中Fe(II)和有机聚合物共同作用下,能有效降低Cr毒性,提高重金属离子固定率。本研究为安全处置电镀污泥及综合利用铅锌冶炼渣提供了新思路。

无机建筑涂料的高分子有机物含量的测试方法——热失重法

无机建筑涂料的高分子有机物含量的测试,可以使用灰分法或热失重法。本文讨论了无机建筑涂料的组分的热失重特点,建立了无机建筑涂料的高分子有机物含量的热失重测试方法,并通过一组试验证明了高分子有机物含量与无机建筑涂料中的乳液添加量成正比。

基于仿生复合材料的纸基双模信号输出检测平台测定二苯甲酮-3

二苯甲酮-3(BP-3)是一种广泛使用的有机紫外线滤光剂,会对环境造成污染且对生物体具有潜在毒性,因此构建能够快速、便携式检测BP-3的方法十分必要。该文将仿生复合材料与纸芯片集成,研制了一种纸基微流控分析装置(μPAD)。仿生复合材料由纳米酶和分子印迹聚合物(MIP)组成,两者分别作为信号产生的催化剂和μPAD的识别单元。首先通过简单、温和的方式合成具有过氧化物酶活性的双金属有机凝胶(Fe/Ru-MOG)纳米酶,并通过本体聚合法将其掺杂到MIP中。Fe/Ru-MOG@MIP-μPAD可通过化学发光(CL)和比色法双信号输出对BP-3进行测定。BP-3通过与MIP特异性结合可减弱Fe/Ru-MOG对H2O2的催化能力,导致CL信号强度降低和比色信号变化。通过手机原位拍摄检测区域的照片记录两种信号,然后转换为灰度值进行量化。双信号分别在1×10^(-9)~1×10^(-7) mol/L(CL)和3×10^(-9)~0.9×10^(-7) mol/L(比色)浓度范围内线性良好,检出限分别为1.63×10^(-10) mol/L(CL)和1.64×10^(-10) mol/L(比色)。且μPAD在土壤、河水和自来水等实际样品的分析中具有良好的选择性和可靠性。作为一种便携、经济的检测工具,μPAD将在快速、现场测定BP-3方面发挥重要作用。

联吡啶类金属配位聚合物对不同有机染料的选择性吸附研究

联吡啶类金属配位聚合物(MOFs)在有机染料吸附中展示出卓越潜力。特别是联吡啶羧酸配体与钌(Ru)离子形成的MOFs,不仅应用在光催化领域,也在吸附分离中表现突出。通过合成不同结构的MOFs,并运用多种分析方法(如X-射线衍射、红外光谱、热重分析等)进行表征。研究着重于这些MOFs对甲基橙、刚果红、罗丹明B等染料的选择性吸附性能,显示出对特定染料的高效吸附和选择性。此外,探讨了金属离子和配体结构对吸附效果的影响,为开发新型吸附材料提供了重要数据。