Monodisperse polystyrene (PS) colloidal spheres were successfully prepared through emulsifier-free emulsion polymerization by controlling the polymerization reaction time, ionic strength of the system, concentration o...Monodisperse polystyrene (PS) colloidal spheres were successfully prepared through emulsifier-free emulsion polymerization by controlling the polymerization reaction time, ionic strength of the system, concentration of the ionic copolymer (sodium p-styrenesulfonate) and other factors. The PS colloidal spheres were assembled into colloidal crystals whose structures were mainly face-centered cubic (fcc) close-packed. Then FDTD method was used to calculate the color-rendering characteristics of the colloidal crystals surface. The calculated results were consistent with the experimental results.展开更多
This paper illuminates the preparation of grating-like polystyrene latex monolayer structure, which can minimize the effects of the size deviation of spheres and the defect transfer on the accuracy as calibration samp...This paper illuminates the preparation of grating-like polystyrene latex monolayer structure, which can minimize the effects of the size deviation of spheres and the defect transfer on the accuracy as calibration samples for micro-scopes. The latex films are grown on freshly cleaved mica substrates by vertical deposition method. The concentration dependence of the structure and the topography of latex films is characterized by optical microscope, ultraviolet- visible transmission spectrum and scanning probe microscope. The origination of such a grating-like structure is also discussed.展开更多
A versatile and reliable approach is created to fabricate wafer-scale colloidal crystal that consists of a monolayer of hexagonally close-packed polystyrene （PS） spheres. Making wafer-scale colloidal crystal is usua...A versatile and reliable approach is created to fabricate wafer-scale colloidal crystal that consists of a monolayer of hexagonally close-packed polystyrene （PS） spheres. Making wafer-scale colloidal crystal is usually challenging, and it lacks a general theoretical guidance for experimental approaches. To obtain the optimal conditions for self-assembly, a systematic statistical design and analysis method is utilized here, which applies the pick-the-winner rule. This new method combines spin-coating and thermal treatment, and introduces a mixture of glycol and ethanol as a dispersion system to assist self-assembly. By controlling the parameters of self-assembly, we improve the quality of colloidal crystal and reduce the effect of noise on the experiment. To our best knowledge, we are first to pave this path to harvest colloidal crystals. Importantly, a theoretical analysis using an energy landscape base on our process is also developed to provide insights into the PS spheres＇ self-assembly.展开更多
Porous NiO-Ce0.8Sm0.2O1.9（NiO-SDC） ceramics with homogeneous pore distribution were prepared using polystyrene （PS） spheres as pore templates. NiO-SDC powders were synthesized by a glycine-nitrate method, ultrason...Porous NiO-Ce0.8Sm0.2O1.9（NiO-SDC） ceramics with homogeneous pore distribution were prepared using polystyrene （PS） spheres as pore templates. NiO-SDC powders were synthesized by a glycine-nitrate method, ultrasonically mixed with PS spheres in ethanol, dried and then pressed into green pellets. The pellets were sintered to yield porous NiO-SDC ceramics. The effects of the sintering temperature on the microstructure and mechanical strength of the ceramics were investigated. NiO-SDC ceramics sintered at 1200 and 1350℃ have interconnected pore structures and high compression strength. When single cells were fabricated using porous NiO-SDC ceramics as anode-supported layers, the peak power density of the cells at 600℃ was 333 and 353 mW.cm-2 for ceramics sintered at 1200 and 1350℃, respectively. The results indicated that these porous ceramic materials are promising for anode substrates for solid oxide fuel cells.展开更多
Energy crisis and environmental pollution are two major challenges facing the development of the world today. Hydrogen energy has attracted worldwide attention due to its high thermal efficiency and zero emission. How...Energy crisis and environmental pollution are two major challenges facing the development of the world today. Hydrogen energy has attracted worldwide attention due to its high thermal efficiency and zero emission. However, it is restricted by the low efficiency and poor stability of the hydrogen evolution reaction (HER) catalyst, which restricts the development and application of hydrogen energy. Therefore, the development of efficient and cheap clean energy catalysts is an important research direction in the development of modern science and technology. In this paper, a highly efficient catalyst for the hydrogen evolution of Co1-xS/ZnS@C composites based on 3D template synthesis is introduced. Electrochemical tests show that the Co1-xS/ZnS@C composite catalyst exhibits very good catalytic activity, including overpotential of only 159 mV at 10 mA / cm2, a Tafel slope of only ~93 mV/dec and very high electrochemical stability. Further material characterization shows that the reason why the Co1-xS/ZnS@C composite catalyst has good catalytic activity is due to the good conductivity of Co1-xS/ZnS, the nanostructure and the synergistic effect between Co1-xS/ZnS encapsulated in the porous carbon. In a word, this work introduces a new preparation scheme for designing and synthesizing high-efficiency HER composite catalyst, which promotes the further application of hydrogen energy.展开更多
By utilizing poly（3-hexylthiophene） （P3HT） polymer nanowires with diameters of -15 nm as the vertical channel material, a polymer nanowire vertical transistor has been demonstrated for the first time. The P3HT nan...By utilizing poly（3-hexylthiophene） （P3HT） polymer nanowires with diameters of -15 nm as the vertical channel material, a polymer nanowire vertical transistor has been demonstrated for the first time. The P3HT nanowires were characterized by absorption spectroscopy and scanning electron microscopy. A saturated output current was created by increasing the thickness of the polymer layers between the electrodes through several spin-coating cycles of the polymer nanowires prepared in a marginal solvent. The carrier mobility was also increased through utilization of polymer nanowires with strong interchain interactions. By introducing a small hole injection barrier between the emitter and semiconducting polymer, an on/off current ratio of 1,500 was obtained. The operating voltage is less than 2 V.展开更多
A layer of zinc oxide(ZnO)micro-grid was deposited on the surface of ZnO film using the DC reactive magnetron sputtering method and the micro-sphere lithography technique on glass substrates.Samples of this layer were...A layer of zinc oxide(ZnO)micro-grid was deposited on the surface of ZnO film using the DC reactive magnetron sputtering method and the micro-sphere lithography technique on glass substrates.Samples of this layer were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),atomic force microscopy(AFM),and ultraviolet-visible light spectroscopy.X-ray diffraction showed the high crystallinity of ZnO film and the regular arrangement of the micro-grid.The microgrid ZnO has a lower specular reflection and a higher diffuse reflection,allowing incident light to reflect two or three times to enhance the usage of light.Photocatalytic degradation experiments on methylene blue using both ZnO micro-grid and ordinary film showed that the ZnO micro-grid has better photocatalytic properties than ordinary film.The ZnO micro-grid enhanced the photocatalytic efficiency of ZnO film by 28%with a degradation time of 300 min.展开更多
文摘Monodisperse polystyrene (PS) colloidal spheres were successfully prepared through emulsifier-free emulsion polymerization by controlling the polymerization reaction time, ionic strength of the system, concentration of the ionic copolymer (sodium p-styrenesulfonate) and other factors. The PS colloidal spheres were assembled into colloidal crystals whose structures were mainly face-centered cubic (fcc) close-packed. Then FDTD method was used to calculate the color-rendering characteristics of the colloidal crystals surface. The calculated results were consistent with the experimental results.
基金supported by Science and Technology Commission of Shanghai Municipality (Grant No 0652NM028)Shanghai Leading Academic Discipline Project of China (B113)the International Research Training Group (IRTG)
文摘This paper illuminates the preparation of grating-like polystyrene latex monolayer structure, which can minimize the effects of the size deviation of spheres and the defect transfer on the accuracy as calibration samples for micro-scopes. The latex films are grown on freshly cleaved mica substrates by vertical deposition method. The concentration dependence of the structure and the topography of latex films is characterized by optical microscope, ultraviolet- visible transmission spectrum and scanning probe microscope. The origination of such a grating-like structure is also discussed.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11504264,51501128,and 61274064)
文摘A versatile and reliable approach is created to fabricate wafer-scale colloidal crystal that consists of a monolayer of hexagonally close-packed polystyrene （PS） spheres. Making wafer-scale colloidal crystal is usually challenging, and it lacks a general theoretical guidance for experimental approaches. To obtain the optimal conditions for self-assembly, a systematic statistical design and analysis method is utilized here, which applies the pick-the-winner rule. This new method combines spin-coating and thermal treatment, and introduces a mixture of glycol and ethanol as a dispersion system to assist self-assembly. By controlling the parameters of self-assembly, we improve the quality of colloidal crystal and reduce the effect of noise on the experiment. To our best knowledge, we are first to pave this path to harvest colloidal crystals. Importantly, a theoretical analysis using an energy landscape base on our process is also developed to provide insights into the PS spheres＇ self-assembly.
基金supported by the Zhejiang Provincial Natural Science Foundation of China (No.Y4080307)the research fund of Shenzhen Key Laboratory of Functional Polymers
文摘Porous NiO-Ce0.8Sm0.2O1.9（NiO-SDC） ceramics with homogeneous pore distribution were prepared using polystyrene （PS） spheres as pore templates. NiO-SDC powders were synthesized by a glycine-nitrate method, ultrasonically mixed with PS spheres in ethanol, dried and then pressed into green pellets. The pellets were sintered to yield porous NiO-SDC ceramics. The effects of the sintering temperature on the microstructure and mechanical strength of the ceramics were investigated. NiO-SDC ceramics sintered at 1200 and 1350℃ have interconnected pore structures and high compression strength. When single cells were fabricated using porous NiO-SDC ceramics as anode-supported layers, the peak power density of the cells at 600℃ was 333 and 353 mW.cm-2 for ceramics sintered at 1200 and 1350℃, respectively. The results indicated that these porous ceramic materials are promising for anode substrates for solid oxide fuel cells.
文摘Energy crisis and environmental pollution are two major challenges facing the development of the world today. Hydrogen energy has attracted worldwide attention due to its high thermal efficiency and zero emission. However, it is restricted by the low efficiency and poor stability of the hydrogen evolution reaction (HER) catalyst, which restricts the development and application of hydrogen energy. Therefore, the development of efficient and cheap clean energy catalysts is an important research direction in the development of modern science and technology. In this paper, a highly efficient catalyst for the hydrogen evolution of Co1-xS/ZnS@C composites based on 3D template synthesis is introduced. Electrochemical tests show that the Co1-xS/ZnS@C composite catalyst exhibits very good catalytic activity, including overpotential of only 159 mV at 10 mA / cm2, a Tafel slope of only ~93 mV/dec and very high electrochemical stability. Further material characterization shows that the reason why the Co1-xS/ZnS@C composite catalyst has good catalytic activity is due to the good conductivity of Co1-xS/ZnS, the nanostructure and the synergistic effect between Co1-xS/ZnS encapsulated in the porous carbon. In a word, this work introduces a new preparation scheme for designing and synthesizing high-efficiency HER composite catalyst, which promotes the further application of hydrogen energy.
文摘By utilizing poly（3-hexylthiophene） （P3HT） polymer nanowires with diameters of -15 nm as the vertical channel material, a polymer nanowire vertical transistor has been demonstrated for the first time. The P3HT nanowires were characterized by absorption spectroscopy and scanning electron microscopy. A saturated output current was created by increasing the thickness of the polymer layers between the electrodes through several spin-coating cycles of the polymer nanowires prepared in a marginal solvent. The carrier mobility was also increased through utilization of polymer nanowires with strong interchain interactions. By introducing a small hole injection barrier between the emitter and semiconducting polymer, an on/off current ratio of 1,500 was obtained. The operating voltage is less than 2 V.
基金the National Natural Science Foundation of China(Grant Nos.50672003 and 50872005)the National Basic Research Program of China(Grant No.2007CB613302)the Fok Ying-Tong Education Foundation(No.111050).
文摘A layer of zinc oxide(ZnO)micro-grid was deposited on the surface of ZnO film using the DC reactive magnetron sputtering method and the micro-sphere lithography technique on glass substrates.Samples of this layer were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),atomic force microscopy(AFM),and ultraviolet-visible light spectroscopy.X-ray diffraction showed the high crystallinity of ZnO film and the regular arrangement of the micro-grid.The microgrid ZnO has a lower specular reflection and a higher diffuse reflection,allowing incident light to reflect two or three times to enhance the usage of light.Photocatalytic degradation experiments on methylene blue using both ZnO micro-grid and ordinary film showed that the ZnO micro-grid has better photocatalytic properties than ordinary film.The ZnO micro-grid enhanced the photocatalytic efficiency of ZnO film by 28%with a degradation time of 300 min.
