Assembly of silver(I) coordination polymers incorporating pyromellitic acid and N-heterocyclic ligands

通讯作者地址: Huang, RB (通讯作者), Xiamen Univ, State Key Lab Phys Chem Solid Surfaces, Coll Chem & Chem Engn, Xiamen 361005, Peoples R China 地址: 1. Xiamen Univ, State Key Lab Phys Chem Solid Surfaces, Coll Chem & Chem Engn, Xiamen 361005, Peoples R China 2. Xiamen Univ, Dept Chem, Coll Chem & Chem Engn, Xiamen 361005, Peoples R China 电子邮件地址: [email protected] mixed ligands coordination polymers [Ag-4(apym)(2)(pma)center dot(H2O)(2)](n) (1), {[Ag-4(dmapym)(4)(pma)center dot(H2O)(2)]center dot(H2O)(6)](n) (2), [Ag-2(apyz)(2)(H(2)pma)center dot(H2O)(4)](n) (3), {[Ag-4(apyz)(2)(pma)center dot(H2O)(2)]center dot(H2O)(2)}(n) (4) and {Ag-4(NH3)(8)(pma)center dot(H2O)(6)](n) (5) (apym = 2-aminopyrimidine, dmapym = 4, 6-dimethyl-2-aminopyrimidine, apyz = 2-aminopyrazine, H(4)pma = pyromellitic acid) were synthesized and characterized. For 1 and 2, as the substituents change from H to methyl, the dimensions of 1-2 decrease from three-dimension (3D) to one-dimension (ID) due to the steric effect of methyl groups. For 3 and 4, as the ratios of Ag2O/apyz/pma vary from 1:1:1 to 2:1:1. the structure of 3 is a 1D ladder structure built from Ag-apyz double chains and pma anions, while the structure of 4 is a two-dimension (2D) grid. As excess ammonia is added to above four reaction systems, the structure of 5 contains unprecedented {[Ag(NH3)(2)](+)}(n) chains and pma anions. The substituent on the pyrimidyl ring, ratios of reactants, solvent systems and ligand isomers intensively influence the coordination environments of metal ion and the coordination modes of the carboxyl group, and thus determine the structures of the coordination polymers. The photoluminescent properties of 1-5 were also investigated. (C) 2010 Elsevier Ltd. All rights reserved.National Natural Science Foundation of China 20721001 MSTC 2007CB81530

Self-assembly of silver(I) coordination polymers from aminopyrimidyl derivatives and malonate acid: From 1D chain to 2D layer

通讯作者地址: Huang, RB (通讯作者), Xiamen Univ, State Key Lab Phys Chem Solid Surfaces, Xiamen 361005, Peoples R China 地址: 1. Xiamen Univ, State Key Lab Phys Chem Solid Surfaces, Xiamen 361005, Peoples R China 2. Xiamen Univ, Dept Chem, Coll Chem & Chem Engn, Xiamen 361005, Peoples R China 电子邮件地址: [email protected] new silver(I) coordination polymers (CPs) of the formula [Ag-2(dmapym)(4)(mal)center dot H2O](n) (1) and [Ag-3(apym)(3)(mal)NO3](n) (2) (dmapym = 2-amino-4,6-dimethylprimidine, apym = 2-aminopyrimidine, H(2)mal = malonate) have been synthesized by reactions of AgNO3 and 2-aminopyrimidyl ligands with malonate under the ammoniacal condition. Both complexes have been characterized by element analysis, IR and single-crystal X-ray diffraction. The monodentate dmapym and tridentate mal ligands link Ag(I) ions to give complex 1 a one-dimensional (1D) H-shaped chain structure. The complex 2 is a two-dimensional (2D) double sheet structure constructed by (4,4) single sheet. Additionally, the hydrogen-bonding and C-H center dot center dot center dot pi interactions also direct the self-assembly of supramolecular architectures. The photoluminescence properties of the 1 and 2 were investigated in the solid state at room temperature. (C) 2010 Elsevier B.V. All rights reserved.National Natural Science Foundation of China 20721001 MSTC 2007CB81530

Influence of symmetric benzene-polycarboxylate acids on the structures of silver-aminopyrimidyl derivative system

通讯作者地址: Huang, RB (通讯作者), Xiamen Univ, Dept Chem, Coll Chem & Chem Engn, Xiamen 361005, Peoples R China 地址: 1. Xiamen Univ, Dept Chem, Coll Chem & Chem Engn, Xiamen 361005, Peoples R China 2. Xiamen Univ, State Key Lab Phys Chem Solid Surfaces, Xiamen 361005, Peoples R China 电子邮件地址: [email protected] novel coordination polymers, [Ag(BTC)(1/3)(ADMP)](n) (1), [Ag(BDC)(1/2)(ADMP)](n) (2) (2-amino-4,6-dimethylpyrimidine = ADMP; H3BTC = 1,3,5-benzenetricarboxylic acid; H2BDC = 1,4-benzenedicarboxylic acid), have been synthesized under the ammoniacal conditions and structurally characterized. In complex 1, H3BTC ligand showing a new coordination mode links silver atoms to generate a two-dimensional (2-D) honeycomb-like structure, which is further linked through ADMP ligands to produce a complicated three-dimensional (3-D) framework. Complex 2 features a 2-D infinite layer framework consisting of binuclear silver clusters, which is further stacked via intermolecular C-methyl-H center dot center dot center dot pi it short contacts and Van der Waals interactions to form a 3-D supramolecular architecture. (C) 2009 Elsevier B.V. All rights reserved.National Natural Science Foundation of China 20721001 MSTC 2007CB81530

A Platform for Coastline Monitoring System by Unmanned Surface Vessel

This paper presents a basic experiment platform to monitor coastline using unmanned surface vessel. This platform has two operating mode, manual work for release and automation for patrol. By swarm intelligent formation control and hunting strategy developed, we can use these methods for the monitor platform. The platform contains control system, sensor system, communication system. The USV (unmanned surface vessel) in the platform can patrol to ensure if there are dangerous situations in the area. They can switch mode to suit for different situation. In this paper, we design the platform system and manufacture the USV. We plan to use out USV to prove the platform

Path planning for swarm AUV visiting communication node

This paper proposes a method for path planning of an underwater robot swarm. The method is based on biological inspired neural network to plan path between robots and communication nodes. The robot swarm is used to search wild sea area. To solve the long distance communication problem, we deploy some communication nodes ahead, forming a communication network under the water. The robots visit the nodes to communicate. With this method, robots can also avoid obstacles in real time. Firstly, put the landscape into grid map. Then build biologically inspired neural network based on the grid map. The node attracts the robots and the obstacles reject the robots through neural activity. At last, robots plan their path by the activity with a steepest gradient descent rule. Simulation result shows the method may lose in local optimum, so we improve the method to avoid repetitive path. The results show that the improvement effective for path planning

Electrochemical Codeposition of HA/Collagen Coating and Preliminary in Vitro Tests

应用电化学恒电流共沉积法在医用纯钛基底上制备羟基磷灰石(HA)/胶原(collagen)复合涂层.SEM和XPS等测试表明:复合涂层呈特定有序的纳-微米二级多孔结构,化学组分为HA和胶原的有机-无机复合.借助体外细胞的培养实验观察种植于不同材料表面的细胞贴壁及生长形态,显示电化学共沉积的复合涂层具有比纯HA或纯钛表面更好的生物相容性.An electrochemical co-deposition technique has been developed to prepare a hydroxyapatite(HA)/collagen composite coating on Ti substrate.The SEM results show that the composite coating exhibits a homogeneous and porous morphology with nano-micro structure.And the XPS results demonstrate that the composite coating is formed by an organic-inorganic hybrization.In vitro cell culture tests reveal that,compared with pure HA and pure Ti,the HA/collagen composite coating exhibit a best biological properties.作者联系地址：厦门大学化学化工学院固体表面物理化学国家重点实验室,厦门大学化学化工学院固体表面物理化学国家重点实验室,厦门大学化学化工学院固体表面物理化学国家重点实验室,厦门大学化学化工学院固体表面物理化学国家重点实验室 福建厦门361005,福建厦门361005,福建厦门361005,福建厦门361005Author's Address: State Key Laboratary of Physical Chemistry of Solid Surfaces,Department of Chemistry,Xiamen University,Xiamen 361005,Fujian,Chin

Electrochemical Capacitance of MnO_2 /PANI Composite

以P123为模板剂,软模板法制备出纳米MnO2.酸性条件下引入苯胺并聚合,得到了MnO2/聚苯胺复合材料.X射线衍射(XRD)、红外光谱(IR),扫描电子显微镜(SEM)表征观察样品的结构、形貌.循环伏安、交流阻抗、恒电流充放电等测试MnO2/聚苯胺电极的电化学性能.结果表明:引入苯胺改变了样品纳米MnO2的形貌.MnO2/聚苯胺电极比容量高达190.8F·g-1,500次循环电极比容量仅衰减4.7%,库仑效率均保持在97%以上.Nano-MnO2 was prepared by using P123 as a soft template.The MnO2 /polyaniline composite was further prepared by polymerization of aniline with the nano-MnO2 in acidic conditions and was investigated by XRD and IR.The morphology of nano-MnO2 observed by SEM was changed with the introduction of aniline.The electrochemical properties of MnO2 /PANI electrode were investigated using cyclic voltammetry,galvanostatic charge-discharge and electrochemical impedance spectroscopy.The specific capacitance of MnO2 /PANI electrode could reach as high as 190.8 F·g-1,which decayed only 4.7% over 500 cycles.And the coulombic efficiency has been maintained at above 97%.作者联系地址：中南大学化学化工学院;Author's Address: College of Chemistry and Chemical engineering,Central South University,Changsha 410083,Hunan,Chin

Architecting Three-Dimensional Networks in Carbon Nanotube Buckypapers for Thermal Interface Materials

<p class="articleBody_abstractText">Carbon nanotube (CNT) buckypaper, which has large specific surface area and tunable network structures, shows great potential in the application of heat dissipation for high power electronic devices. In this article, we report that the heat conduction in a buckypaper depends greatly on CNT network formation, in which CNT structures, lengths, and orientations are important issues. The buckypaper composed of multiwalled CNTs with large diameter (around 50 nm) and suitable length (1&ndash;10 &mu;m) shows lower thermal impedance compared with those made by longer CNTs with smaller diameter. The thermal impedance of such buckypapers can be reduced to 0.27 cm²&middot;K/W, lower than that of commercialized graphite foil and thermal grease. Thus, the buckypaper may serve as a promising candidate for advanced thermal interface materials. Detailed structural characterization indicates that the three-dimensional networks of buckypapers, with CNT orientations perpendicular to the surfaces, result in both the reduction of thermal contact resistance and the enhancement of heat conduction along the thickness.</p

Enhancement of carbon nanotube fibres using different solvents and polymers

<p id="sp005">Liquid infiltration is an efficient way to densify carbon nanotubes (CNTs) and was used to strengthen CNT fibres in the method of array spinning. Rather than the volatility, the dipole moment of solvent plays a more important role in determining the densification level. The fibres densified by highly polar but non-volatile solvents such as <em>N</em>,<em>N</em>-dimethylformamide, dimethyl sulphoxide, and <em>N</em>-methyl-2-pyrrolidone were 100&ndash;200&nbsp;MPa stronger than those by ethanol and acetone. Ethylene glycol is the most efficient solvent due to its two polar OH groups and improved the fibre strength to 1.45&nbsp;GPa. Long chain or cross-linked polymers like polyvinyl alcohol, polyimide, and bismaleimide (BMI) were introduced into CNT fibres by infiltration with aid of polar solvents. These polymers reinforced the fibres significantly, as they can connect non-neighboring CNTs and benefit the load transfer. The strongest CNT/BMI fibre was 2.38&nbsp;GPa in strength and 110&nbsp;GPa in modulus.</p