Lithium metal stands out as an exceptionally promising anode material,boasting an extraordinarily high theoretical capacity and impressive energy density.Despite these advantageous characters,the issues of dendrite fo...Lithium metal stands out as an exceptionally promising anode material,boasting an extraordinarily high theoretical capacity and impressive energy density.Despite these advantageous characters,the issues of dendrite formation and volume expansion of lithium metal anodes lead to performance decay and safety concerns,significantly impeding their advancement towards widespread commercial viability.Herein,a lithium-rich Li-B-In composite anode with abundant lithophilic sites and outstanding structural stability is reported to address the mentioned challenges.The evenly distributed Li-In alloy in the bulk phase of anodes act as mixed ion/electron conductors and nucleation sites,facilitating accelerated Li ions transport dynamics and suppressing lithium dendrite formation.Additionally,these micron-sized Li-In particles in LiB fibers framework can enhance overall structural integrity and provide sufficient interior space to accommodate the volume changes during cycling.The electrochemical performance of Li-B-In composite anode exhibits long-term cyclability,superior rate performance and high-capacity retention.This work confirms that the synergy between a 3 D skeleton and hetero-metallic lithiophilic sites can achieve stable and durable lithium metal anodes,offering innovative insights for the practical deployment of lithium metal batteries.展开更多
A novel three-dimension(3D)graphene/MgO composite was synthesized through self-assembly and embedding MgO nanoparticle in reduced graphene in situ.Fourier transform infrared(FT-IR)spectroscopy,thermal gravimetric anal...A novel three-dimension(3D)graphene/MgO composite was synthesized through self-assembly and embedding MgO nanoparticle in reduced graphene in situ.Fourier transform infrared(FT-IR)spectroscopy,thermal gravimetric analysis(TGA),scanning electron microscopy(SEM),transmission electron microscope(TEM),powder X-raydiffraction(XRD)and X-rayphotoelectron spectroscopy(XPS)were employed to characterize the prepared 3D graphene/MgO composite.The adsorption performance of some metal ions on 3D graphene/MgO was investigated.The results showed that the adsorption capacity was greater than 3D graphene and the maximum adsorption capacity at 25℃was found to be 358.96 mg/g,388.4 mg/g and 169.8 mg/g for Pb^2+,Cd^2+and Cu^2+,respectively.The adsorption kinetic conformed to the pseudo-second-order kinetic model and the adsorption isotherm was well described by Langmuir model.The thermodynamic constants revealed that the sorption process was endothermic and spontaneous in nature.Based on the results of the removal of heavy metal ions from metal smelting wastewater,it can be concluded that the prepared 3D graphene/MgO composite is an effective and potential adsorbent.展开更多
The industrial silica fume pretreated by nitric acid at 80 °C was re-used in this work. Then, the obtained silica nanoparticles were surface functionalized by silane coupling agents, such as(3-Mercaptopropyl) tri...The industrial silica fume pretreated by nitric acid at 80 °C was re-used in this work. Then, the obtained silica nanoparticles were surface functionalized by silane coupling agents, such as(3-Mercaptopropyl) triethoxysilane(MPTES) and(3-Amincpropyl) trithoxysilane(APTES). Some further modifications were studied by chloroaceetyl choride and 1,8-Diaminoaphalene for amino modified silica. The surface functionalized silica nanoparticles were characterized by Fourier transform infrared(FI-IR) and X-ray photoelectron spectroscopy(XPS). The prepared adsorbent of surface functionalized silica nanoparticles with differential function groups were investigated in the selective adsorption about Pb2+, Cu2+, Hg2+, Cd2+ and Zn2+ions in aqueous solutions. The results show that the(3-Mercaptopropyl) triethoxysilane functionalized silica nanoparticles(SiO2-MPTES) play an important role in the selective adsorption of Cu2+ and Hg2+, the(3-Amincpropyl) trithoxysilane(APTES) functionalized silica nanoparticles(SiO2-APTES) exhibited maximum removal efficiency towards Pb2+ and Hg2+, the 1,8-Diaminoaphalene functionalized silica nanoparticles was excellent for removal of Hg2+ at room temperature, respectively.展开更多
Heavy metal biosorption is an effective process for the removal and recovery of heavy metal ions.Equilibrium isotherms obtained experimentally are usually correlated empirically with commonly used adsorption models, w...Heavy metal biosorption is an effective process for the removal and recovery of heavy metal ions.Equilibrium isotherms obtained experimentally are usually correlated empirically with commonly used adsorption models, without considering the underlying mechanisms of biosorption.Commonly used models for correlating biosorption isotherm data are briefly reviewed and the use of the adsorption models in correlating the desorption processes is analysed.A set of biosorption/desorption experiments for a marine alga derived biosorbent are carried out to test the use of the adsorption models in the desorption process.Experimental data indicate that the amount of the heavy metal ions desorbed from the biomass could not be calculated with the adsorption models.This suggests that the empirical use of adsorption models in the correlation may not be valid when the reversibility of the biosorption equlibrium in the desorption process needs to be considered.Therefore,mechanism based biosorption models are needed for better correlation of equilibrium isotherm data.展开更多
The chelates of metal ions with EDTA covalently linked to the 5′end of oligodeoxyribonuclotides(ODN),i.e,ODN5′EDTA·M(Ⅱ),are prepared,in which M(Ⅱ) is Fe(Ⅱ),Co(Ⅱ) or Cu(Ⅱ).The optimum pH value for forming t...The chelates of metal ions with EDTA covalently linked to the 5′end of oligodeoxyribonuclotides(ODN),i.e,ODN5′EDTA·M(Ⅱ),are prepared,in which M(Ⅱ) is Fe(Ⅱ),Co(Ⅱ) or Cu(Ⅱ).The optimum pH value for forming these three chelates is calculated.For ODN5′EDTA Fe(Ⅱ) pH value is 5.8 to 8.6,pH 4.6～8.1 for ODN5′EDTA Co(Ⅱ),and pH 3.4～5.7 for ODN5′EDTA Cu(Ⅱ).Under such pH value conditions neither can Mg(Ⅱ) ion,necessary for cleavage reaction,be competitive with Fe(Ⅱ),Co(Ⅱ) or Cu(Ⅱ) to form EDTA chelate,nor can it be precipitated.The cleavage mechanism of ODN5′EDTA Fe(Ⅱ) for DNA duplex is discussed.Modified ODN binds with DNA duplex in the major groove via hydrogen bond to form triple helix.In the presense of oxygen and reducing agent dithiothreitol,hydroxyl radicals species are generated as intermediates by catalysis of metal ions,and then oxidize the ribo ring and cut the doublestranded DNA at the sites close to the EDTA· Fe(Ⅱ).展开更多
Three types of metal ions barium(Ⅱ),nickel(Ⅱ)and cerium(Ⅲ)complexity of ATN drug have been prepared and characterized using molar conductance method,FT-IR,electronic,and 1H-NMR analysis measurements.The chemical an...Three types of metal ions barium(Ⅱ),nickel(Ⅱ)and cerium(Ⅲ)complexity of ATN drug have been prepared and characterized using molar conductance method,FT-IR,electronic,and 1H-NMR analysis measurements.The chemical and physical results for all atenolol complexes are agreement with the speculated structures.For the divalent(Ba&Ni)and trivalent(Ce)metal atenolol a molar ratio 1∶2 was established.Qualitative chemical analysis showed that for the divalent metal complexes,the chloride ions are not involved in the complexes,suggesting that all of these complexes,[Ba(ATN)2]·2 H2O and[Ni(ATN)2(H2O)2]·4 H2O are neutral.However,for the cerium(Ⅲ)complex,[Ce(ATN)2(NO3)]·3 H2O,the nitrate group is existed inside the coordination sphere.ATN make astable metal complexity with barium(Ⅱ),nickel(Ⅱ)and cerium(Ⅲ)ions.Electronic absorption analysis of Atenolol give two fundamental peaks at 225 nm and 274 nm refers to variation in transition electrons of ligand,UV spectral analysis of the three complexity obtained give asymmetric broad band in the range 200~400 nm,the reults are convenient with the suggestion of metal-nitrogen and metal-oxygen bonds.The infrared analysis data proved that ATN act as bidentate ligand through the N atom of the-NH group and O atom of the deprotonated alcoholic OH group.Nickel(Ⅱ)and cerium(Ⅲ)complexity make six-coordinate geometry,whereas the barium(Ⅱ)complex exhibit four-coordinate geometry.Ni(Ⅱ)-ATN complex has an effective magnetic moment equal 3.12 B.M,that is assigned to octahedral structure.The 1H-NMR spectral results of Ba(Ⅱ)-ATN complexity give strong signal at^4.00 ppm due to protons of-CH2 that influenced by low degree due to complexity.These results confirm the position of chelation through the N atom of the-NH group and O atom of the deprotonated alcoholic OH group.展开更多
Pipemidic acid is one of an efficient quinolone antibacterial drug.Thecomplexitybetween pipemidic acid“Hpipc”withgallium(Ⅲ),germanium(Ⅳ)and silicon(Ⅳ)afforded three molecular formulas of[Ga(pipc)2(H 2O)(Cl)]·...Pipemidic acid is one of an efficient quinolone antibacterial drug.Thecomplexitybetween pipemidic acid“Hpipc”withgallium(Ⅲ),germanium(Ⅳ)and silicon(Ⅳ)afforded three molecular formulas of[Ga(pipc)2(H 2O)(Cl)]·4H 2O,1,[Ge(pipc)2(Cl)2]·4H 2O,2 and[Si(pipc)2(Cl)2]·4H 2O,3 complexes.These three new complexes were characterized based on elemental analysis,conductance,FTIR,UV-Vis,^1HNMR and XRD spectroscopy.The pipc chelate exhibits O,O coordinated through the carbonyl(C O)and carboxylato(COO)of both oxygen atoms.Six coordinate geometry was proposed regarding complexes of 2 and 3,so the axial position was occupied by two coordinated chlorideatoms.In vitro,the antibacterial,antifungal,and anti-cancer assessments concerning the synthesized pipc complexes were scanned.These complexes have an excellent anti-microbial activity.展开更多
To investigate effect of metallic ion activation on different particle sizes of quartz in butyl xanthate solution,six common ions(Pb^(2+),Cu^(2+),Fe^(3+),Fe^(2+),Mg^(2+) and Ca^(2+)) were introduced as activators.The ...To investigate effect of metallic ion activation on different particle sizes of quartz in butyl xanthate solution,six common ions(Pb^(2+),Cu^(2+),Fe^(3+),Fe^(2+),Mg^(2+) and Ca^(2+)) were introduced as activators.The approaches of micro-flotation,adsorption test and zeta potential measurement were adopted to reveal the mechanism of ion activation.The results show that Pb^(2+),Cu^(2+) and Fe^(3+) are effective activators for the flotation of quartz in butyl xanthate solution because of their absorption on activated quartz surface.Average recoveries of fine particles(<37 μm) are greater than those of coarser particles(37-74 μm),suggesting that the former is easier to be activated and more likely to be floated and thus entrained in sulphide concentrate.From another perspective,addition of metallic ions(Pb^(2+),Cu^(2+) and Fe^(3+)) renders zeta potentials move positively,and addition of the same metallic ions and butyl xanthate makes zeta potential drop apparently,which support a mechanism where they adsorb onto quartz surface,resulting in an expected increase in butyl xanthate collector adsorption with a concomitant increase in the flotation recoveries.展开更多
Lithium-ion batteries(LIBs)are used in electric vehicles and portable smart devices,but lithium resources are dwindling and there is an increasing demand which has to be catered for.Sodium ion batteries(SIBs),which ar...Lithium-ion batteries(LIBs)are used in electric vehicles and portable smart devices,but lithium resources are dwindling and there is an increasing demand which has to be catered for.Sodium ion batteries(SIBs),which are less costly,are a promising replacement for LIBs because of the abundant natural reserves of sodium.The anode of a SIB is a necessary component of the battery but is less understood than the cathode.This review outlines the development of various types of anodes,including carbonbased,metallic and organic,which operate using different reaction mechanisms such as intercalation,alloying and conversion,and considers their challenges and prospects.Strategies for modifying their structures by doping and coating,and also modifying the solid electrolyte interface are discussed.In addition,this review also discusses the challenges encountered by the anode of SIBs and the solutions.展开更多
A cobalt-based metal-organic framework[Co_(3)(L)_(2)(1,4-bib)_(4)]·4H_(2)O(Co-MOF)was prepared using 5-[(4-carboxyphenoxy)methyl]isophthalic acid(H_(3)L)and 1,4-bis(1H-imidazol-1-yl)benzene(1,4-bib)as ligands.The...A cobalt-based metal-organic framework[Co_(3)(L)_(2)(1,4-bib)_(4)]·4H_(2)O(Co-MOF)was prepared using 5-[(4-carboxyphenoxy)methyl]isophthalic acid(H_(3)L)and 1,4-bis(1H-imidazol-1-yl)benzene(1,4-bib)as ligands.Then,an electrochemical sensor modified with Co-MOF on a glassy carbon electrode(Co-MOF@GCE)was constructed for detecting Cd^(2+)and Pb^(2+)in aqueous solutions.The sensor exhibited a linear range of 1.0-16.0µmol·L^(-1)with a detection limit(LOD)of 4.609 nmol·L^(-1)for Cd^(2+),and 0.5-10.0µmol·L^(-1)with an LOD of 1.307 nmol·L^(-1)for Pb^(2+).Simultaneous detection of both ions within 0.5-7.0µmol·L^(-1)achieved LOD values of 0.47 nmol·L^(-1)(Cd^(2+))and 0.008 nmol·L^(-1)(Pb^(2+)),respectively.Analysis of real water samples(tap water,mineral water,and river water)yielded recoveries of 95%-105%,validating practical applicability.Density functional theory(DFT)calculations reveal that synergistic interactions between cobalt centers and N/O atoms enhance adsorption and electron-transfer efficiency.CCDC:2160744.展开更多
Te(Ⅳ),Se(Ⅳ),V(Ⅲ),Nb(Ⅴ)and Ta(Ⅴ)complexes of indole-3-acetic acid(IAAH)ligand were synthesized,characterized by elemental analysis and various spectroscopic techniques like,IR,1H-NMR,X-ray powder diffraction,UV-Vi...Te(Ⅳ),Se(Ⅳ),V(Ⅲ),Nb(Ⅴ)and Ta(Ⅴ)complexes of indole-3-acetic acid(IAAH)ligand were synthesized,characterized by elemental analysis and various spectroscopic techniques like,IR,1H-NMR,X-ray powder diffraction,UV-Visible,thermogravimetry analysis,magnetic measurements,molar conductance and surface morphology using SEM.All the synthesized complexes of IAAH ligand have 1∶2 stoichiometry of the types[Te(IAA)2(NH 3)2]·2Cl(Ⅰ),[Se(IAA)2(NH 3)2]·2Cl(Ⅱ),[V(IAA)2(NH 3)(Cl)](Ⅲ),[Nb(IAA)2(Cl)3](Ⅳ),and[Ta(IAA)2(Cl)3](Ⅴ).Spectral analysis indicates octahedral geometry for the Te(Ⅳ),Se(Ⅳ)and V(Ⅲ)complexes,whereas both Nb(Ⅴ)and Ta(Ⅴ)have a seven-coordination.The bonding sites are the oxygen atoms of carboxylate group for the deprotonated indole-3-acetic acid(IAA)ligand.The thermogravimetry analysis studies gave evidence for the presence of other coordinated molecules(Cl or NH 3)in the composition of IAA complexes,which were further supported by IR and micro analytical measurements.The higher molar conductance data of tellurium and selenium(Ⅳ)complexes reveal that these chelates are electrolytes,while low conductivity values for the vanadium(Ⅲ),niobium and tantalum(Ⅴ)chelates indicated a non-electrolytes.To test the antibacterial property of the five complexes in this study,four bacterial strains Klebsiella(G-),Escherichia coli(G-),Staphylococcus aureus(G+)and Staphylococcus epidermidis(G+)were used in the investigation.The effects of the five complexes in the cytotoxicity of Caco-2 and Mcf-7 human cancer cell lines were studied Neutral red uptake assay for the estimation of cell viability/cytotoxicity protocol.展开更多
In this article, three types of metal ions with different oxidation state as mercury(Ⅱ), cerium(Ⅲ) thorium(Ⅳ) have been reacted with captopril drug(CAP). The isolated solid complexes were explained using elemental ...In this article, three types of metal ions with different oxidation state as mercury(Ⅱ), cerium(Ⅲ) thorium(Ⅳ) have been reacted with captopril drug(CAP). The isolated solid complexes were explained using elemental analysis, conductance measurements, infrared and 1H-NMR spectroscopy as well as the thermo gravimetric(TG/DTG) analysis. The micro analytical and spectroscopic results for all CAP complexes were agreement with the speculated structures. The stoichiometry for divalent Hg^2+, trivalent Ce^3+ and tetravalent Th(4+) metal ions with CAP ligand was established with 1∶2(M(n+):CAP) molar ratio. The qualitative analysis showed that in case of the mercury(Ⅱ) complex, the chloride ions didn't involved in the complexity, suggesting formula [Hg(CAP)2] in neutral form. However, regarding both Ce(Ⅲ) and Th(Ⅳ) complexes as [Ce(CAP)2(NO3)]·3 H2O and [Th(CAP)2(NO3)2(H2O)]·3 H2O formulas, the nitrate group is existed inside the coordination sphere. The infrared analysis data proved that CAP drug act as a bidentate ligand with the metal ions of Ce(Ⅲ) and Th(Ⅳ) through oxygen carbonyl group C=O and oxygen of the deprotonated carboxylic COOH group, while for the Hg(Ⅱ) complex, the CAP acts as a bidentate ligand through oxygen of C=O group and sulfur atom of the deprotonated -SH group. Thorium(Ⅵ) complex has a nine-coordinate geometry, while Hg(Ⅱ) and Ce(Ⅲ) have a four and six-coordination behaviors respectively. The 1H-NMR data of the CAP compound has a singlet sharp signal at 1.90 ppm due to the proton of -SH group, this peak absent in the spectrum of the Hg(Ⅱ) CAP complex upon the deprotonated of thiol group.展开更多
本研究旨在探究不同金属离子(NaCl、KCl、CaCl_(2)、AlCl_(3)和FeCl_(3))对乳清分离蛋白(whey protein isolate,WPI)纤维聚合物聚合动力学、形态和结构的影响。结果表明,不同金属离子影响了WPI纤维聚合物的最终结构和特征。NaCl、KCl和C...本研究旨在探究不同金属离子(NaCl、KCl、CaCl_(2)、AlCl_(3)和FeCl_(3))对乳清分离蛋白(whey protein isolate,WPI)纤维聚合物聚合动力学、形态和结构的影响。结果表明,不同金属离子影响了WPI纤维聚合物的最终结构和特征。NaCl、KCl和CaCl_(2)对WPI的聚集影响较小,增加了溶液pH和电导率,而AlCl_(3)和FeCl_(3)加速了WPI的聚集,降低了溶液pH,增加了溶液电导率;与原始WPI纤维聚合物硫黄素T(Th T)荧光强度(388.92)相比,NaCl、KCl和CaCl_(2)增加Th T荧光强度分别至465.39、433.37和486.83,增加了WPI纤维聚合物的生成量,AlCl_(3)和FeCl_(3)降低Th T荧光强度分别至228.81和90.24,降低了WPI纤维聚合物的生成量;不同金属离子均改变了WPI聚合动力学,降低了(df/dt)_(max)值,并改变了滞后时间;NaCl、KCl和CaCl_(2)对WPI纤维聚合物的形态影响较小,AlCl_(3)和FeCl_(3)使WPI纤维聚合物更团簇、粗而杂乱;傅里叶红外光谱结果表明,NaCl、KCl和CaCl_(2)促进β-折叠结构生成,而AlCl_(3)和FeCl_(3)抑制了β-折叠生成,不同金属离子的加入均改变了纤维中β-链间的特征距离。这些结果为利用WPI制备不同聚集形态的纤维聚合物提供了科学依据。展开更多
基金Project(2023YFC3905904)supported by the National Key Research and Development Program,ChinaProject(2220197000221)supported by the Team of Foshan National Hi-Tech Industrial Development Zone Industrialization Entrepreneurial Teams Program,ChinaProject(2024ZZTS0373)supported by the Central South University Graduate Student Autonomous Exploration Innovative Programme,China。
文摘Lithium metal stands out as an exceptionally promising anode material,boasting an extraordinarily high theoretical capacity and impressive energy density.Despite these advantageous characters,the issues of dendrite formation and volume expansion of lithium metal anodes lead to performance decay and safety concerns,significantly impeding their advancement towards widespread commercial viability.Herein,a lithium-rich Li-B-In composite anode with abundant lithophilic sites and outstanding structural stability is reported to address the mentioned challenges.The evenly distributed Li-In alloy in the bulk phase of anodes act as mixed ion/electron conductors and nucleation sites,facilitating accelerated Li ions transport dynamics and suppressing lithium dendrite formation.Additionally,these micron-sized Li-In particles in LiB fibers framework can enhance overall structural integrity and provide sufficient interior space to accommodate the volume changes during cycling.The electrochemical performance of Li-B-In composite anode exhibits long-term cyclability,superior rate performance and high-capacity retention.This work confirms that the synergy between a 3 D skeleton and hetero-metallic lithiophilic sites can achieve stable and durable lithium metal anodes,offering innovative insights for the practical deployment of lithium metal batteries.
基金Projects(21571191,51674292) supported by the National Natural Science Foundation of ChinaProject(2016JJ1023) supported by the Natural Science Foundation of Hunan Province,ChinaProject(2018TP1003) supported by the Key Laboratory of Hunan Province for Water Environment and Agriculture Product Safety,China
文摘A novel three-dimension(3D)graphene/MgO composite was synthesized through self-assembly and embedding MgO nanoparticle in reduced graphene in situ.Fourier transform infrared(FT-IR)spectroscopy,thermal gravimetric analysis(TGA),scanning electron microscopy(SEM),transmission electron microscope(TEM),powder X-raydiffraction(XRD)and X-rayphotoelectron spectroscopy(XPS)were employed to characterize the prepared 3D graphene/MgO composite.The adsorption performance of some metal ions on 3D graphene/MgO was investigated.The results showed that the adsorption capacity was greater than 3D graphene and the maximum adsorption capacity at 25℃was found to be 358.96 mg/g,388.4 mg/g and 169.8 mg/g for Pb^2+,Cd^2+and Cu^2+,respectively.The adsorption kinetic conformed to the pseudo-second-order kinetic model and the adsorption isotherm was well described by Langmuir model.The thermodynamic constants revealed that the sorption process was endothermic and spontaneous in nature.Based on the results of the removal of heavy metal ions from metal smelting wastewater,it can be concluded that the prepared 3D graphene/MgO composite is an effective and potential adsorbent.
基金Project(2012CB722803)supported by the Key Project of National Basic Research and Development Program of ChinaProject(U1202271)supported by the National Natural Science Foundation of ChinaProject(IRT1250)supported by the Program for Innovative Research Team in University of Ministry of Education of China
文摘The industrial silica fume pretreated by nitric acid at 80 °C was re-used in this work. Then, the obtained silica nanoparticles were surface functionalized by silane coupling agents, such as(3-Mercaptopropyl) triethoxysilane(MPTES) and(3-Amincpropyl) trithoxysilane(APTES). Some further modifications were studied by chloroaceetyl choride and 1,8-Diaminoaphalene for amino modified silica. The surface functionalized silica nanoparticles were characterized by Fourier transform infrared(FI-IR) and X-ray photoelectron spectroscopy(XPS). The prepared adsorbent of surface functionalized silica nanoparticles with differential function groups were investigated in the selective adsorption about Pb2+, Cu2+, Hg2+, Cd2+ and Zn2+ions in aqueous solutions. The results show that the(3-Mercaptopropyl) triethoxysilane functionalized silica nanoparticles(SiO2-MPTES) play an important role in the selective adsorption of Cu2+ and Hg2+, the(3-Amincpropyl) trithoxysilane(APTES) functionalized silica nanoparticles(SiO2-APTES) exhibited maximum removal efficiency towards Pb2+ and Hg2+, the 1,8-Diaminoaphalene functionalized silica nanoparticles was excellent for removal of Hg2+ at room temperature, respectively.
文摘Heavy metal biosorption is an effective process for the removal and recovery of heavy metal ions.Equilibrium isotherms obtained experimentally are usually correlated empirically with commonly used adsorption models, without considering the underlying mechanisms of biosorption.Commonly used models for correlating biosorption isotherm data are briefly reviewed and the use of the adsorption models in correlating the desorption processes is analysed.A set of biosorption/desorption experiments for a marine alga derived biosorbent are carried out to test the use of the adsorption models in the desorption process.Experimental data indicate that the amount of the heavy metal ions desorbed from the biomass could not be calculated with the adsorption models.This suggests that the empirical use of adsorption models in the correlation may not be valid when the reversibility of the biosorption equlibrium in the desorption process needs to be considered.Therefore,mechanism based biosorption models are needed for better correlation of equilibrium isotherm data.
文摘The chelates of metal ions with EDTA covalently linked to the 5′end of oligodeoxyribonuclotides(ODN),i.e,ODN5′EDTA·M(Ⅱ),are prepared,in which M(Ⅱ) is Fe(Ⅱ),Co(Ⅱ) or Cu(Ⅱ).The optimum pH value for forming these three chelates is calculated.For ODN5′EDTA Fe(Ⅱ) pH value is 5.8 to 8.6,pH 4.6～8.1 for ODN5′EDTA Co(Ⅱ),and pH 3.4～5.7 for ODN5′EDTA Cu(Ⅱ).Under such pH value conditions neither can Mg(Ⅱ) ion,necessary for cleavage reaction,be competitive with Fe(Ⅱ),Co(Ⅱ) or Cu(Ⅱ) to form EDTA chelate,nor can it be precipitated.The cleavage mechanism of ODN5′EDTA Fe(Ⅱ) for DNA duplex is discussed.Modified ODN binds with DNA duplex in the major groove via hydrogen bond to form triple helix.In the presense of oxygen and reducing agent dithiothreitol,hydroxyl radicals species are generated as intermediates by catalysis of metal ions,and then oxidize the ribo ring and cut the doublestranded DNA at the sites close to the EDTA· Fe(Ⅱ).
文摘Three types of metal ions barium(Ⅱ),nickel(Ⅱ)and cerium(Ⅲ)complexity of ATN drug have been prepared and characterized using molar conductance method,FT-IR,electronic,and 1H-NMR analysis measurements.The chemical and physical results for all atenolol complexes are agreement with the speculated structures.For the divalent(Ba&Ni)and trivalent(Ce)metal atenolol a molar ratio 1∶2 was established.Qualitative chemical analysis showed that for the divalent metal complexes,the chloride ions are not involved in the complexes,suggesting that all of these complexes,[Ba(ATN)2]·2 H2O and[Ni(ATN)2(H2O)2]·4 H2O are neutral.However,for the cerium(Ⅲ)complex,[Ce(ATN)2(NO3)]·3 H2O,the nitrate group is existed inside the coordination sphere.ATN make astable metal complexity with barium(Ⅱ),nickel(Ⅱ)and cerium(Ⅲ)ions.Electronic absorption analysis of Atenolol give two fundamental peaks at 225 nm and 274 nm refers to variation in transition electrons of ligand,UV spectral analysis of the three complexity obtained give asymmetric broad band in the range 200~400 nm,the reults are convenient with the suggestion of metal-nitrogen and metal-oxygen bonds.The infrared analysis data proved that ATN act as bidentate ligand through the N atom of the-NH group and O atom of the deprotonated alcoholic OH group.Nickel(Ⅱ)and cerium(Ⅲ)complexity make six-coordinate geometry,whereas the barium(Ⅱ)complex exhibit four-coordinate geometry.Ni(Ⅱ)-ATN complex has an effective magnetic moment equal 3.12 B.M,that is assigned to octahedral structure.The 1H-NMR spectral results of Ba(Ⅱ)-ATN complexity give strong signal at^4.00 ppm due to protons of-CH2 that influenced by low degree due to complexity.These results confirm the position of chelation through the N atom of the-NH group and O atom of the deprotonated alcoholic OH group.
基金funded by the Deanship of Scientific Research at Princess Nourah bint Abdulrahman University through the Fast-track Research Funding Program。
文摘Pipemidic acid is one of an efficient quinolone antibacterial drug.Thecomplexitybetween pipemidic acid“Hpipc”withgallium(Ⅲ),germanium(Ⅳ)and silicon(Ⅳ)afforded three molecular formulas of[Ga(pipc)2(H 2O)(Cl)]·4H 2O,1,[Ge(pipc)2(Cl)2]·4H 2O,2 and[Si(pipc)2(Cl)2]·4H 2O,3 complexes.These three new complexes were characterized based on elemental analysis,conductance,FTIR,UV-Vis,^1HNMR and XRD spectroscopy.The pipc chelate exhibits O,O coordinated through the carbonyl(C O)and carboxylato(COO)of both oxygen atoms.Six coordinate geometry was proposed regarding complexes of 2 and 3,so the axial position was occupied by two coordinated chlorideatoms.In vitro,the antibacterial,antifungal,and anti-cancer assessments concerning the synthesized pipc complexes were scanned.These complexes have an excellent anti-microbial activity.
基金Project(51274255)supported by the National Natural Science Foundation of ChinaProject(2015CX005)supported by Innovation Driven Plan of Central South University,China+1 种基金Project(2016RS2016)supported by Hunan Provincial Science and Technology Leader(Innovation Team of Interface Chemistry of Efficient and Clean Utilization of Complex Mineral Resources),ChinaProject supported by the Postdoctoral Research Station of Central South University,China
文摘To investigate effect of metallic ion activation on different particle sizes of quartz in butyl xanthate solution,six common ions(Pb^(2+),Cu^(2+),Fe^(3+),Fe^(2+),Mg^(2+) and Ca^(2+)) were introduced as activators.The approaches of micro-flotation,adsorption test and zeta potential measurement were adopted to reveal the mechanism of ion activation.The results show that Pb^(2+),Cu^(2+) and Fe^(3+) are effective activators for the flotation of quartz in butyl xanthate solution because of their absorption on activated quartz surface.Average recoveries of fine particles(<37 μm) are greater than those of coarser particles(37-74 μm),suggesting that the former is easier to be activated and more likely to be floated and thus entrained in sulphide concentrate.From another perspective,addition of metallic ions(Pb^(2+),Cu^(2+) and Fe^(3+)) renders zeta potentials move positively,and addition of the same metallic ions and butyl xanthate makes zeta potential drop apparently,which support a mechanism where they adsorb onto quartz surface,resulting in an expected increase in butyl xanthate collector adsorption with a concomitant increase in the flotation recoveries.
文摘Lithium-ion batteries(LIBs)are used in electric vehicles and portable smart devices,but lithium resources are dwindling and there is an increasing demand which has to be catered for.Sodium ion batteries(SIBs),which are less costly,are a promising replacement for LIBs because of the abundant natural reserves of sodium.The anode of a SIB is a necessary component of the battery but is less understood than the cathode.This review outlines the development of various types of anodes,including carbonbased,metallic and organic,which operate using different reaction mechanisms such as intercalation,alloying and conversion,and considers their challenges and prospects.Strategies for modifying their structures by doping and coating,and also modifying the solid electrolyte interface are discussed.In addition,this review also discusses the challenges encountered by the anode of SIBs and the solutions.
文摘A cobalt-based metal-organic framework[Co_(3)(L)_(2)(1,4-bib)_(4)]·4H_(2)O(Co-MOF)was prepared using 5-[(4-carboxyphenoxy)methyl]isophthalic acid(H_(3)L)and 1,4-bis(1H-imidazol-1-yl)benzene(1,4-bib)as ligands.Then,an electrochemical sensor modified with Co-MOF on a glassy carbon electrode(Co-MOF@GCE)was constructed for detecting Cd^(2+)and Pb^(2+)in aqueous solutions.The sensor exhibited a linear range of 1.0-16.0µmol·L^(-1)with a detection limit(LOD)of 4.609 nmol·L^(-1)for Cd^(2+),and 0.5-10.0µmol·L^(-1)with an LOD of 1.307 nmol·L^(-1)for Pb^(2+).Simultaneous detection of both ions within 0.5-7.0µmol·L^(-1)achieved LOD values of 0.47 nmol·L^(-1)(Cd^(2+))and 0.008 nmol·L^(-1)(Pb^(2+)),respectively.Analysis of real water samples(tap water,mineral water,and river water)yielded recoveries of 95%-105%,validating practical applicability.Density functional theory(DFT)calculations reveal that synergistic interactions between cobalt centers and N/O atoms enhance adsorption and electron-transfer efficiency.CCDC:2160744.
基金the Deanship of Scientific Research at Princess Nourah bint Abdulrahman University,through the Research Groups Program Grant no.(RGP-1440-0001)。
文摘Te(Ⅳ),Se(Ⅳ),V(Ⅲ),Nb(Ⅴ)and Ta(Ⅴ)complexes of indole-3-acetic acid(IAAH)ligand were synthesized,characterized by elemental analysis and various spectroscopic techniques like,IR,1H-NMR,X-ray powder diffraction,UV-Visible,thermogravimetry analysis,magnetic measurements,molar conductance and surface morphology using SEM.All the synthesized complexes of IAAH ligand have 1∶2 stoichiometry of the types[Te(IAA)2(NH 3)2]·2Cl(Ⅰ),[Se(IAA)2(NH 3)2]·2Cl(Ⅱ),[V(IAA)2(NH 3)(Cl)](Ⅲ),[Nb(IAA)2(Cl)3](Ⅳ),and[Ta(IAA)2(Cl)3](Ⅴ).Spectral analysis indicates octahedral geometry for the Te(Ⅳ),Se(Ⅳ)and V(Ⅲ)complexes,whereas both Nb(Ⅴ)and Ta(Ⅴ)have a seven-coordination.The bonding sites are the oxygen atoms of carboxylate group for the deprotonated indole-3-acetic acid(IAA)ligand.The thermogravimetry analysis studies gave evidence for the presence of other coordinated molecules(Cl or NH 3)in the composition of IAA complexes,which were further supported by IR and micro analytical measurements.The higher molar conductance data of tellurium and selenium(Ⅳ)complexes reveal that these chelates are electrolytes,while low conductivity values for the vanadium(Ⅲ),niobium and tantalum(Ⅴ)chelates indicated a non-electrolytes.To test the antibacterial property of the five complexes in this study,four bacterial strains Klebsiella(G-),Escherichia coli(G-),Staphylococcus aureus(G+)and Staphylococcus epidermidis(G+)were used in the investigation.The effects of the five complexes in the cytotoxicity of Caco-2 and Mcf-7 human cancer cell lines were studied Neutral red uptake assay for the estimation of cell viability/cytotoxicity protocol.
文摘In this article, three types of metal ions with different oxidation state as mercury(Ⅱ), cerium(Ⅲ) thorium(Ⅳ) have been reacted with captopril drug(CAP). The isolated solid complexes were explained using elemental analysis, conductance measurements, infrared and 1H-NMR spectroscopy as well as the thermo gravimetric(TG/DTG) analysis. The micro analytical and spectroscopic results for all CAP complexes were agreement with the speculated structures. The stoichiometry for divalent Hg^2+, trivalent Ce^3+ and tetravalent Th(4+) metal ions with CAP ligand was established with 1∶2(M(n+):CAP) molar ratio. The qualitative analysis showed that in case of the mercury(Ⅱ) complex, the chloride ions didn't involved in the complexity, suggesting formula [Hg(CAP)2] in neutral form. However, regarding both Ce(Ⅲ) and Th(Ⅳ) complexes as [Ce(CAP)2(NO3)]·3 H2O and [Th(CAP)2(NO3)2(H2O)]·3 H2O formulas, the nitrate group is existed inside the coordination sphere. The infrared analysis data proved that CAP drug act as a bidentate ligand with the metal ions of Ce(Ⅲ) and Th(Ⅳ) through oxygen carbonyl group C=O and oxygen of the deprotonated carboxylic COOH group, while for the Hg(Ⅱ) complex, the CAP acts as a bidentate ligand through oxygen of C=O group and sulfur atom of the deprotonated -SH group. Thorium(Ⅵ) complex has a nine-coordinate geometry, while Hg(Ⅱ) and Ce(Ⅲ) have a four and six-coordination behaviors respectively. The 1H-NMR data of the CAP compound has a singlet sharp signal at 1.90 ppm due to the proton of -SH group, this peak absent in the spectrum of the Hg(Ⅱ) CAP complex upon the deprotonated of thiol group.
