In this investigation, polymeric nanocomposite membranes（PNMs） were prepared via incorporating zinc oxide（ZnO） into poly（ether-block-amide）(PEBAX-1074) polymer matrix with different loadings. The neat membrane a...In this investigation, polymeric nanocomposite membranes（PNMs） were prepared via incorporating zinc oxide（ZnO） into poly（ether-block-amide）(PEBAX-1074) polymer matrix with different loadings. The neat membrane and nanocomposite membranes were prepared via solution casting and solution blending methods, respectively. The fabricated membranes were characterized by field emission scanning electron microscopy（FESEM） to survey cross-sectional morphologies and thermal gravimetric analysis（TGA）to study thermal stability. Fourier transform infrared（FT-IR） and X-ray diffraction（XRD） analyses were also employed to identify variations of the chemical bonds and crystal structure of the membranes, respectively. Permeation of pure gases, CO, CHand Nthrough the prepared neat and nanocomposite membranes was studied at pressures of 3–18 bar and temperature of 25 °C. The obtained results showed that the fabricated nanocomposite membranes exhibit better separation performance compared to the neat PEBAX membrane in terms of both permeability and selectivity. As an example, at temperature of 25 °C and pressure of 3 bar, COpermeability, ideal CO/CHand CO/Nselectivity values for the neat PEBAX membrane are 110.67 Barrer, 11.09 and 50.08, respectively, while those values are 152.27 Barrer,13.52 and 62.15 for PEBAX/ZnO nanocomposite membrane containing 8 wt% ZnO.展开更多
A diode-pumped actively Q-switched Raman laser is demonstrated, with YV04 employed as Raman active medium, based on a ceramic Nd：YAG laser operating at 1444nm. The first-stokes Raman generation at 1657nm is achieved....A diode-pumped actively Q-switched Raman laser is demonstrated, with YV04 employed as Raman active medium, based on a ceramic Nd：YAG laser operating at 1444nm. The first-stokes Raman generation at 1657nm is achieved. A maximum output power of as high as 612mW is obtained under a pump power of 20. 7 W and at a pulse repetition frequency rate of 20kHz, corresponding to an optical-to-optical conversion efficiency of 3%.展开更多
Membranes have attracted much attention as economical methods for industrial chemical processes. The effects of the titanium dioxide nanoparticle load on the morphology and CO2/CH4 separation performance of poly (ethe...Membranes have attracted much attention as economical methods for industrial chemical processes. The effects of the titanium dioxide nanoparticle load on the morphology and CO2/CH4 separation performance of poly (ether-block-amide)(PEBAX-1657) mixed matrix membranes (MMMs) were investigated from pressures of 3-12 bar and temperatures of 30℃-60℃. The PEBAX membranes were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, thermal gravimetric analysis, atomic force microscopy and tensile strength analysis. The incorporation of TiO2 nanoparticles into the polymeric MMMs improved the CO2/CH4 gas separation performance (both the permeability and selectivity) of the membranes. The CO2 permeability and ideal CO2/CH4 selectivity values of the nanocomposite membrane loaded with 8 wt-% TiO2 were 172.32 Barrer and 24.79, respectively whereas those of the neat membrane were 129.87 Barrer and 21.39, respectively.展开更多
文摘In this investigation, polymeric nanocomposite membranes（PNMs） were prepared via incorporating zinc oxide（ZnO） into poly（ether-block-amide）(PEBAX-1074) polymer matrix with different loadings. The neat membrane and nanocomposite membranes were prepared via solution casting and solution blending methods, respectively. The fabricated membranes were characterized by field emission scanning electron microscopy（FESEM） to survey cross-sectional morphologies and thermal gravimetric analysis（TGA）to study thermal stability. Fourier transform infrared（FT-IR） and X-ray diffraction（XRD） analyses were also employed to identify variations of the chemical bonds and crystal structure of the membranes, respectively. Permeation of pure gases, CO, CHand Nthrough the prepared neat and nanocomposite membranes was studied at pressures of 3–18 bar and temperature of 25 °C. The obtained results showed that the fabricated nanocomposite membranes exhibit better separation performance compared to the neat PEBAX membrane in terms of both permeability and selectivity. As an example, at temperature of 25 °C and pressure of 3 bar, COpermeability, ideal CO/CHand CO/Nselectivity values for the neat PEBAX membrane are 110.67 Barrer, 11.09 and 50.08, respectively, while those values are 152.27 Barrer,13.52 and 62.15 for PEBAX/ZnO nanocomposite membrane containing 8 wt% ZnO.
基金Supported by the Foundation of the State Key Laboratory of Crystal Material of Shandong University under Grant No KF1101the Foundation of Shandong University under Grant No 1170072613176+2 种基金the National Natural Science Foundation of China under Grant Nos 11004122 and 11204160the Special Grade of China Postdoctoral Science Foundation under Grant No 201104627the Independent Innovation Foundation of Shandong University under Grant No 2011GN058
文摘A diode-pumped actively Q-switched Raman laser is demonstrated, with YV04 employed as Raman active medium, based on a ceramic Nd：YAG laser operating at 1444nm. The first-stokes Raman generation at 1657nm is achieved. A maximum output power of as high as 612mW is obtained under a pump power of 20. 7 W and at a pulse repetition frequency rate of 20kHz, corresponding to an optical-to-optical conversion efficiency of 3%.
基金the Iran National Science Foundation (INSF) for supporting this research (Grant No.96008182).
文摘Membranes have attracted much attention as economical methods for industrial chemical processes. The effects of the titanium dioxide nanoparticle load on the morphology and CO2/CH4 separation performance of poly (ether-block-amide)(PEBAX-1657) mixed matrix membranes (MMMs) were investigated from pressures of 3-12 bar and temperatures of 30℃-60℃. The PEBAX membranes were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, thermal gravimetric analysis, atomic force microscopy and tensile strength analysis. The incorporation of TiO2 nanoparticles into the polymeric MMMs improved the CO2/CH4 gas separation performance (both the permeability and selectivity) of the membranes. The CO2 permeability and ideal CO2/CH4 selectivity values of the nanocomposite membrane loaded with 8 wt-% TiO2 were 172.32 Barrer and 24.79, respectively whereas those of the neat membrane were 129.87 Barrer and 21.39, respectively.
