A new kind of amorphous molecular materials containing azobenzene chromophors has been synthesized.The precursor molecule was prepared by esterification between 1,3,5-benzenetricarbonyl chloride and N-ethyl-N-hydroxye...A new kind of amorphous molecular materials containing azobenzene chromophors has been synthesized.The precursor molecule was prepared by esterification between 1,3,5-benzenetricarbonyl chloride and N-ethyl-N-hydroxyethyl-aniline.The precursor molecule was then reacted with the diazonium salts of 5-aminoisophthalic acid to introduce donor-acceptor azobenzene chromophores at the peripheral groups.The azobenzene amorphous molecular material was characterized by the spectroscopic methods and thermal analysis.The azo compound synthesized can form stable amorphous glass.The amorphous molecular material was used to fabricate surface relief gratings(SRG) by exposing spin-coated thin films of the azo compound to an interference pattern of Ar^+ laser beams at modest intensity(120 mW/cm^2).The surface modulation was about 390 nm and the first order of diffraction efficiency was up to 23%.展开更多
采用外来金属离子诱导策略,通过一步溶剂热法成功制备了一系列In x Fe y-aMOF材料,并探究其在析氧反应中的应用.XRD、TEM和N 2吸附结果表明:Fe 3+的引入使原始晶态In-MOF失去长程有序结构,无序的纳米结构拥有较高的比表面积和丰富裸露...采用外来金属离子诱导策略,通过一步溶剂热法成功制备了一系列In x Fe y-aMOF材料,并探究其在析氧反应中的应用.XRD、TEM和N 2吸附结果表明:Fe 3+的引入使原始晶态In-MOF失去长程有序结构,无序的纳米结构拥有较高的比表面积和丰富裸露的金属活性位点,有利于电催化反应进行.Fe-aMOF表现出最佳的析氧反应活性:在电流密度为0.01 A/cm^(2)时,过电位仅为258.2 mV,塔菲尔斜率为45.4 mV/dec.此外,Fe-aMOF还具有长期稳定性,在0.01 A/cm^(2)时至少可以连续运行110 h.该研究为合理设计和构建新一代高效电催化剂提供了一种独特的思路.展开更多
The effects of crystallization on the corrosion resistance of a Cu52.5Ti30Zr11.5Ni6 bulk amorphous alloy in 1 mol/L HCl, and 6 mol/L NaOH solutions were studied. The amorphous alloy was identified by differential ther...The effects of crystallization on the corrosion resistance of a Cu52.5Ti30Zr11.5Ni6 bulk amorphous alloy in 1 mol/L HCl, and 6 mol/L NaOH solutions were studied. The amorphous alloy was identified by differential thermal analysis(DSC) and by X-ray diffraction(XRD). The partially and fully crystallized alloys were prepared by controlling the annealing temperatures at 738 and 873 K for 1 and 12 min, respectively, and the corrosion resistances of those annealed alloys were compared with that of the amorphous alloy by immersion test and potentiodynamic measurements in 1 mol/L HCl and 6 mol/L NaOH solutions. The results show that the partially crystallized alloy exhibits high corrosion resistance, whereas full crystallization results in deteriorated corrosion resistance compared with that of the as-cast amorphous alloy.展开更多
Amorphous carbon (a-C) films and amorphous carbon films incorporating with the nitrogen (a-C∶N) were deposited on silicon substrates in a radio-frequency driven plasma enhanced chemical vapour deposition system, whil...Amorphous carbon (a-C) films and amorphous carbon films incorporating with the nitrogen (a-C∶N) were deposited on silicon substrates in a radio-frequency driven plasma enhanced chemical vapour deposition system, while the surface electrical properties of films were investigated by electrochemical capacitance-voltage measurements. It was examined the effect of the interface defects on the properties and deduced that the conducting type of a-C∶N films was n-type. Subsequently, a comparative studies of a-C and a-C∶N films were performed by photoluminescence spectra depending on the temperature. With the decrease of the temperature, the main band with peak energy of 2.48 eV in the a-C∶N films was more intense compared with the other three bands caused by amorphous C in the a-C films.展开更多
It has been a challenge to fully understand the structural characteristics of laser-irradiation induced amorphous(L-a) Ge2Sb2Te5(GST) alloy due to the difficulties of collecting diffraction data from high purity speci...It has been a challenge to fully understand the structural characteristics of laser-irradiation induced amorphous(L-a) Ge2Sb2Te5(GST) alloy due to the difficulties of collecting diffraction data from high purity specimens. In this paper,by fabricating GST thin films on different substrates,we exhibit an effective way of preparing L-a GST dots in submicron scale on various types of specially designed transmission electron microscope(TEM) grids. The structural characteristics of L-a GST in the form of pair distribution functions(PDF) can be achieved on single dots of L-a GST via selected area electron diffraction(SAED) . This general approach would be convenient for precisely producing laser-irradiation induced materials in submicron scale for structural investigation.展开更多
Photofunctional materials with room-temperature phosphorescence（RTP）commonly appeared in expensive metal-coordination complexes and rare-earth-based compounds.Recently,the metal-free organic RTP materials have been ...Photofunctional materials with room-temperature phosphorescence（RTP）commonly appeared in expensive metal-coordination complexes and rare-earth-based compounds.Recently,the metal-free organic RTP materials have been paid growing attention from scientific community because of the ease of molecular design,low cost as well as potential applications in molecular switches,chemical sensors and biological imaging.To date,efficient RTP materials with high quantum yield are still very limited due to the T_1-S_0 spinforbidden process and weak spin-orbital coupling.Current mechanism based on crystallization-induced or aggregationinduced phosphorescence may serve as an effective way to enhance the RTP[1,2];展开更多
文摘A new kind of amorphous molecular materials containing azobenzene chromophors has been synthesized.The precursor molecule was prepared by esterification between 1,3,5-benzenetricarbonyl chloride and N-ethyl-N-hydroxyethyl-aniline.The precursor molecule was then reacted with the diazonium salts of 5-aminoisophthalic acid to introduce donor-acceptor azobenzene chromophores at the peripheral groups.The azobenzene amorphous molecular material was characterized by the spectroscopic methods and thermal analysis.The azo compound synthesized can form stable amorphous glass.The amorphous molecular material was used to fabricate surface relief gratings(SRG) by exposing spin-coated thin films of the azo compound to an interference pattern of Ar^+ laser beams at modest intensity(120 mW/cm^2).The surface modulation was about 390 nm and the first order of diffraction efficiency was up to 23%.
基金National Test and Evaluation Platform for Advanced Materials-Primary Center Project (TC170A5SU)National Test and Evaluation Platform for Advanced Materials-Nonferrous Metals Center Project (TC190H3ZW/2)。
基金Project(50371072) supported by the National Natural Science Foundation of ChinaProject(05FJ4048) supported by the Provincial Science and Technology Department Foundation of Hunan, China
文摘The effects of crystallization on the corrosion resistance of a Cu52.5Ti30Zr11.5Ni6 bulk amorphous alloy in 1 mol/L HCl, and 6 mol/L NaOH solutions were studied. The amorphous alloy was identified by differential thermal analysis(DSC) and by X-ray diffraction(XRD). The partially and fully crystallized alloys were prepared by controlling the annealing temperatures at 738 and 873 K for 1 and 12 min, respectively, and the corrosion resistances of those annealed alloys were compared with that of the amorphous alloy by immersion test and potentiodynamic measurements in 1 mol/L HCl and 6 mol/L NaOH solutions. The results show that the partially crystallized alloy exhibits high corrosion resistance, whereas full crystallization results in deteriorated corrosion resistance compared with that of the as-cast amorphous alloy.
文摘Amorphous carbon (a-C) films and amorphous carbon films incorporating with the nitrogen (a-C∶N) were deposited on silicon substrates in a radio-frequency driven plasma enhanced chemical vapour deposition system, while the surface electrical properties of films were investigated by electrochemical capacitance-voltage measurements. It was examined the effect of the interface defects on the properties and deduced that the conducting type of a-C∶N films was n-type. Subsequently, a comparative studies of a-C and a-C∶N films were performed by photoluminescence spectra depending on the temperature. With the decrease of the temperature, the main band with peak energy of 2.48 eV in the a-C∶N films was more intense compared with the other three bands caused by amorphous C in the a-C films.
基金supported by the National Basic Research Program of China (Grant Nos.2007CB935400 and 2009CB623700)
文摘It has been a challenge to fully understand the structural characteristics of laser-irradiation induced amorphous(L-a) Ge2Sb2Te5(GST) alloy due to the difficulties of collecting diffraction data from high purity specimens. In this paper,by fabricating GST thin films on different substrates,we exhibit an effective way of preparing L-a GST dots in submicron scale on various types of specially designed transmission electron microscope(TEM) grids. The structural characteristics of L-a GST in the form of pair distribution functions(PDF) can be achieved on single dots of L-a GST via selected area electron diffraction(SAED) . This general approach would be convenient for precisely producing laser-irradiation induced materials in submicron scale for structural investigation.
文摘Photofunctional materials with room-temperature phosphorescence（RTP）commonly appeared in expensive metal-coordination complexes and rare-earth-based compounds.Recently,the metal-free organic RTP materials have been paid growing attention from scientific community because of the ease of molecular design,low cost as well as potential applications in molecular switches,chemical sensors and biological imaging.To date,efficient RTP materials with high quantum yield are still very limited due to the T_1-S_0 spinforbidden process and weak spin-orbital coupling.Current mechanism based on crystallization-induced or aggregationinduced phosphorescence may serve as an effective way to enhance the RTP[1,2];
