A series of new polyamides 3a-d containing aryl-azo, ether and sulfone groups in the main chain were synthesized from bis[4-(4-aminophenoxy)phenyl sulfone] 1 and several azo aromatic diacyl chlorides 2a-d by the low...
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A series of new polyamides 3a-d containing aryl-azo, ether and sulfone groups in the main chain were synthesized from bis[4-(4-aminophenoxy)phenyl sulfone] 1 and several azo aromatic diacyl chlorides 2a-d by the low temperature solution polycondensation technique. FTIR spectroscopy, nuclear magnetic resonance (NMR) and elemental analyses confirmed the structure of these polymers. Owing to the aryl and amide groups in the main chain, these polymers exhibit photochromic properties as well as excellent thermal stabilities. The transition temperatures (Tg) are between 242 and 265℃, and the char yields at 800 ℃ in nitrogen atmosphere were above 39%. Based on incorporation of flexible ether linkages and polar sulfone groups, the polyamides show desirable solubility in organic solvents such as DMAc, N,N-dimethylformamide (DMF), N-methyl-2-pyrroidinone (NMP) and dimethylsulfoxide (DMSO). And it is exemplified that polyamide containing 2 and 2' substitutes performed better solubility.
A steady nano organic-inorganic perovskite hybrid with [H(2)3-AMP](3/2)Fe(CN)(6) (3-AMP = 3-methylaminopyridine) was prepared in the air. The structure is an unusual layered organic-inorganic type. The resulting hybri...
A steady nano organic-inorganic perovskite hybrid with [H(2)3-AMP](3/2)Fe(CN)(6) (3-AMP = 3-methylaminopyridine) was prepared in the air. The structure is an unusual layered organic-inorganic type. The resulting hybrid enveloped in paraffin to prepare [H(2)3-AMP](3/2)Fe(CN)(6) paste electrode (HPE) shows good electrochemical activity and a couple of oxidation and reduction peaks with potential of cyclic voltammometry (CV) at around 440 mV and 30 mV. Compared with that on CPE, oxidation potential of Fe(CN)(6) (3-) on HPE shifts negatively 259.7 mV and that of reduction shifts positively 338.7 mV, which exhibits that [H(2)3-AMP](3/2)Fe(CN)(6) can accelerate the electron-transfer to improve the electrochemical reaction reversibility. Such characteristics of [H(2)3-AMP](3/2)Fe(CN)(6) have been employed to prepare the DNA biosensor. The single-strand DNA (ssDNA) and double-strand DNA (dsDNA) immobilized on HPE, respectively, can improve the square wave voltammometry (SWV) current and SWV potential shifts positively. The effect of pH was evaluated. And there is hybridization peak on SWV curve using HPE immobilized ssDNA in the complementary ssDNA solution. And HPE immobilized ssDNA can be utilized to monitor the DNA hybridization and detect complementary ssDNA, covering range from 3.24 x 10(-7) to 6.72 x 10(-5) g/mL with detection limit of 1.57 x 10(-7) g/mL. The DNA biosensor exhibits a good stability and reproducibility.
Abstract A systematic research was performed about diffusion kinetics of adsorbing F − dissolved in water for carbonate hydroxyapatite (CHAP) from the natural hydroxyapatite which was modified by adulterating with CO ...
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Abstract A systematic research was performed about diffusion kinetics of adsorbing F − dissolved in water for carbonate hydroxyapatite (CHAP) from the natural hydroxyapatite which was modified by adulterating with CO 2 3 . The result shows that the speed of F − adsorption is controlled by membrane diffusion when F − concentration is relatively low, which is expressed by the kinetic equation of diffusion Q =0.0005( C 1 - C )( t - t 1 )+0.3967, or by vacancy diffusion when F − concentration is relatively high, which is expressed by the kinetic equation of diffusion In[ C (o, t )]=8.4718-0.5048ln t . Based on the feature of CHAP for adsorbing F − dissolved in water and its special channel of the structure of CO 2 3 - modified hydroxyapatite, models of vacancy diffusion and membrane diffusion were established.
The spherical agglomerated particles were fabricated by spray drying with the powders of NiO, Cr2O3 and TiO2. Plasma spray power, which has good property of flowability, was acquired by heat treatment from the particl...
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The spherical agglomerated particles were fabricated by spray drying with the powders of NiO, Cr2O3 and TiO2. Plasma spray power, which has good property of flowability, was acquired by heat treatment from the particles at 1200℃ in the reducing atmosphere. Dark and uniform coating of More than 50 μm thick was deposited on the copper sheet substrate by plasma spraying. It is found that the infrared normal total emissivity of the coating is up to 0.91 at 600℃ by infrared radiation testing. The X-ray diffraction analysis shows that the formation of (Cr0.88Ti0.12)2O3 and spinel structural NiCr2O4 in the coating is the main reason for high efficient infrared radiation, and the phase structure and performance of coating is favorable under the thermal cycle between room temperature and 600℃.
For more than half of a century, morphotropic phase boundary (MPB) in ferroelectric materials has drawn constant interest because it can significantly enhance the piezoelectric properties. However, MPB has been studie...
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For more than half of a century, morphotropic phase boundary (MPB) in ferroelectric materials has drawn constant interest because it can significantly enhance the piezoelectric properties. However, MPB has been studied merely in ferroelectric systems, not in another large class of ferroic systems, the ferromagnets. In this Letter, we report the existence of an MPB in a ferromagnetic system TbCo2−DyCo2. Such a magnetic MPB involves a first-order magnetoelastic transition, at which both magnetization direction and crystal structure change simultaneously. The MPB composition demonstrates a 3–6 times larger “figure of merit” of magnetostrictive response compared with that of the off-MPB compositions. The finding of MPB in ferromagnets may help to discover novel high-performance magnetostrictive and even magnetoelectric materials.
With the aim of designing photobioreactors (PBR) based on a smart exploitation of microalgae for the production of biofuels and metabolites of interest, this paper describes a novel approach where cyanobacteria are en...
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The synergetic effects of codoped Zr4+ and F- ions within anatase hollow microspheres produced by a fluoridemediated self-transformation strategy are investigated and discussed. The concomitant participation of Fpromo...
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The topography of material surface has important influence on cell behavior and physiological functions. Groove-like pattern has drawn much attention among various patterns, due to the phenomenon of "contact guid...
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The topography of material surface has important influence on cell behavior and physiological functions. Groove-like pattern has drawn much attention among various patterns, due to the phenomenon of "contact guidance" induced by this kind of topography. This review mainly focuses on "contact guidance" formation as well as its influence on cell behavior and physiological effects. The possible mechanisms of "contact guidance" formation were discussed. The research trend and the potential applications were also suggested.
Molybdenum-doped vanadium pentoxide (Mo-doped V2O5) thin films with doping levels of 3-10 mol% were prepared by dip-coating technique from a stable Mo-doped V2O5 sol synthesized by sol-gel and hydrothermal reaction. T...
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We report Langmuir-Blodgett (LB) based assembly of vanadium dioxide (VO2) nanowires. VO2 nanowires were functlonallzed with stearic acid (SA) and cetyltrlmethylammonlum bromide (CTAB) and then spread on the surface In...
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