Jun-Ran Li

Synthesis and crystal structure of the potassium lanthanum complex with triethylenetetra-aminehexaacetic acid (H6TTHA): K[KLa(HTTHA)(H2O)]·8H2O

Abstract The title complex, K[KLa(HTTHA)(H2O]·8H2O, was synthesized in aqueous solution and its crystal structure was determined by X-ray diffraction. In the complex, the ten-coordinated lanthanum ion is bonded by four nitrogen atoms and six carboxyl oxygen atoms of the same triethylenetetraaminehexaacetic acid (H6TTHA) molecule. The coordination polyhedron of lanthanum can be described as a distorted bicapped square antiprism. The crystal is composed of one dimensional infinite chains.

SYNTHESIS AND CRYSTAL STRUCTURE OF THE POTASSIUM YTTERBIUM COMPLEX WITH TRIETHYLENETETRAAMINEHEXAACETIC ACID : K3YB(TTHA)(H2O)5

Abstract The title complex [K3Yb(TTHA)(H2O)5], where TTHA6− is triethylenetetraaminehexaacetic acid anion was synthesized in aqueous solution, and its crystal structure was determined by X-ray diffraction. In the complex, the ytterbium ion is coordinated by four nitrogen atoms and five carboxyl oxygen atoms of the same TTHA6− anion. The coordination number of the ytterbium ion is 9, and its coordination polyhedron can be described as a distorted monocapped square antiprism. Each Yb(TTHA)3− is further connected by K+ ions through carboxyl groups of TTHA6− ion to form a three dimensional network structure.

Two novel types of Ln 2 M 2 clusters bridged by cyanide and carboxylate simultaneously

Two novel complexes [Sm 2 (Ac) 2 (phen) 4 (H 2 O) 2 {Fe(CN) 5 (NO)} 2 ] 1 and [Dy 2 Ac) 2 (phen) 4 (H 2 O) 2 {Fe(CN) 5 (NO)} 2 ] . 8H 2 O 2 have been synthesized and structurally and magnetically characterized. Complex I crystallizes in the orthorhombic space group of Aba2 with a = 18.6179(3), b = 16.2001(3), c = 20.9875(4) A, and Z = 4, while complex 2 crystallizes in the monoclinic space group P2 1 /n with a = 12.0748(3), b = 27.3276(5), c = 22.9096(6) A, β = 93.1001(8)°, and Z = 4. A cyanide and carboxylate anions are bridging tetranuclear clusters, but exhibit different structural features. In 1, two [Fe(CN) 5 (NO)] 2- fragments connect the same Sm 3+ cation in a [Sm 2 (Ac) 2 ] dimer unit to produce a T-shaped motif. In 2, two [Fe(CN) 5 (NO)] 2- fragments attach to the two different Dy 3+ cations in a [Dy 2 (Ac) 2 ] dimer unit, leading to a U-shaped topology. Both examples represent novel structural types among tetranuclear Ln 2 M 2 clusters.

The highly stable open frameworks and the adsorption performance of a 3D Er–Cu coordination polymer containing spacious channels

A novel 3D Er–Cu heteronuclear coordination polymer, f½Er2Cu3L6 �� 7H2Ogn (H2L ¼ iminodiacetic acid), containing large amount of spacious channels was synthesized. Its crystal structure was determined by X-ray diffraction. The highly stable skeleton and the adsorption performance of this polymer were demonstrated by thermogravimetric analysis (TGA) and X-ray diffraction (XRD) analysis. 2003 Elsevier Science B.V. All rights reserved.

A HIGHLY ACTIVE ELECTRORHEOLOGICAL MATERIAL, NANO-SIZED BOEHMITE: INFLUENCE OF HYDROXYL ON ITS ELECTRORHEOLOGICAL PROPERTY

A highly active electrorheological (ER) material, nano-sized boehmite, AlO(OH), has been obtained. The relative shear stress (τr = τE/τ0, τ0 and τE are the shear stresses at the electric field strength of 0 kV/mm and 4.2 kV/mm, respectively) of the suspension (25 wt.%) in silicone oil reached 212 at a shear rate of 14.5 s−1 and a DC electric field. The dielectric property, conductivity, surface energy, microstructure, and composition of boehmite [AlO(OH)] and alkaline alumina containing both AlO(OH) and Al2O3 have been studied. The results showed that the hydroxyl group plays a critical role in influencing the ER activity of the material by changing the dielectric property and conductivity of the material.

Preparation and Electrorheological Property of NaNO3-Doped Y2O3 Material

Abstract A new class of electrorheological (ER) material using rare earth (RE = Y) oxide as the substrate, NaNO3doped Y2O3 materials, were synthesized using Na2CO3 and Y(NO3)3 as starting materials. Their ER performance, dielectric property, and crystal structure were studied. The results show that doping NaNO3 can markedly enhance the ER activity of the Y2O3 material. For the suspensions of these materials in dimethyl silicone oil, a clear dependence of the shear stress on the doping degree of NaNO3 was observed, and the optimal value of Na/Y molar ratio of 0.6 in doping degree was discovered, the relative viscosity ηr(ηE/ηO, E = 4.2 kV·mm−1) of the suspensions is nine times higher than that of pure Y2O3 material. The new results of the relationship between ER effect and the microstructure were obtained, which are helpful for further understanding the mechanism of ER effect and synthesizing a good ER material.

Preparation and Electrorheological Property of Y4O(OH)9(NO3)-NH4NO3 Materials

Abstract The new electrorheological (ER) material, a particle material composed of Y 4 O(OH) 9 (NO 3 ) and NH 4 NO 3 , was obtained. They display better ER performance. The shear stress of the suspension of Y 4 O(OH) 9 (NO 3 ) (NH 4 NO 3 ) 2.8 material in dimethyl silicone oil reaches 1469 Pa at an electric field strength ( E ) of 4.2 kV. mm −1 and the shear rate (γ) of 150s −1 . The relative shear stress, τ E /τ 0 (τ E and τ 0 are the shear stresses at E = 4.2 and O kV-mm −1 , respectively), is up to 29, which is 19 times that of pure Y 2 O 3 material. The dielectric and conductive property of the materials play important roles in the modification of the ER effect of the particle materials. The researches on these new ER materials are very useful for obtaining a better understanding on the mechanism of the ER effect and finding an ideal ER material.

New multifunction materials with both electrorheological performance and luminescence property

Novel multifunctional materials, the composites AlOOH-NaYFTb5 and AlOOH-NaYFTb10, containing AlO(OH) and β-NaYF4:5%Tb3+, have been synthesized via a facile hydrothermal route and a simple grinding method. The boehmite [AlO(OH)], yttrium nitrate [Y(NO3)3·6H2O], terbium nitrate, [Tb(NO3)3·6H2O], sodium citrate (Na3C6H5O7·2H2O) and sodium fluoride (NaF) were used as starting materials. The composition, electrorheological (ER) performance, and luminescence property of the functional materials were studied. Our results show that the composites not only have good electrorheological (ER) performance, but also have good optics property. The relative shear stress τr (τr = τE/τ0, τE and τ0 are the shear stresses at the electric field strength E = 4 and 0 kV/mm, respectively) values of the suspension (25 wt.%) of AlOOHNaYFTb5 material in silicone oil are all larger than 50 in a shear rate ranging from 0.06 to 26 s−1, the τr value reaches 1333 at a shear rate of 0.06 s−1. The material with such high ER activity and favorable luminescence performance is advantageous in its application as a multifunctional material.

MOLECULE-BASED ELECTRORHEOLOGICAL MATERIAL, ELECTRORHEOLOGICAL PERFORMANCE AND MOLECULE STRUCTURE

Molecule-based electrorheological (ER) materials as a novel type of ER materials, a series of compounds using melamine (C3N6H6) as the substrate, have been synthesized using orthophosphoric acid (H3PO4), oxalic acid (H2C2O4), 4-toluenesulfonic acid (PTA, C7H8O3S) and 5-sulfosalicylic acid (SSA, C7H6O6S), respectively as starting materials. The ER performance and dielectric property of materials have been studied. The results show that these materials have ER activity. The unusual relationship between dielectric property and ER property of these materials was found and discussed. The composition and structure of molecule are the dominant factors, the function group plays an important role, in influencing ER performance of the molecule-based ER material.

MICROSTRUCTURE AND ELECTRORHEOLOGICAL PROPERTY OF PURE TiO2 PARTICLE MATERIAL

JUAN WANG AND SHAO-HUA ZHANG School of Vehicle and Transmission Engineering, Beijing Institute of Technology, Beijing, 100081, China Pure titanium dioxide (Ti02) particle materials were prepared by hydrolyzing titanium tetrachloride (TiC14). The microstructures of these materials were determined by X-ray difiactometer (XRD) and accelerated surface area & porosimetry apparatus (BET) etc. The Ti02 materials obtained by calcinations under different temperatures revealed distinctly different microstructures in terms of crystal structure type, surface area, pore size, pore volume and grain size. The relationship between the microstructure of the Ti02 materials and their electrorheolagical (ER) activity was investigated.