随着人类社会发展,CO2的过量排放造成了温室效应的加剧。我国作为农业大国,秸秆产量巨大但资源化利用水平不高。本文以玉米秸秆为原材料制备了生物炭,掺入Pebax 1657中制成混合基质膜(MMMs)用于CO2分离纯化和玉米秸秆高价值利用。结果表...随着人类社会发展,CO2的过量排放造成了温室效应的加剧。我国作为农业大国,秸秆产量巨大但资源化利用水平不高。本文以玉米秸秆为原材料制备了生物炭,掺入Pebax 1657中制成混合基质膜(MMMs)用于CO2分离纯化和玉米秸秆高价值利用。结果表明,与纯Pebax 1657膜相比,生物炭填料的掺入提升了MMMs的性能,且随着掺杂比的提升气体分离性能呈现上升趋势。在掺杂比为4 wt%时性能最佳。玉米秸秆生物炭最佳CO2渗透系数和选择性分别为125.7 Barrer和81.78,相比纯Pebax 1657膜提升了69%和34%。生物炭掺杂Pebax 1657混合基质膜具有良好的分离CO2性能。With the development of human society, the excessive emission of CO2 has exacerbated the greenhouse effect. As a large agricultural country, straw production of China is huge, but its resource utilization level remains low. In this study, biochar was prepared from corn stalk, and then dopped into Pebax 1657 to produce mixed matrix membranes (MMMs), the obtained MMMs was used for CO2 separation from gas mixture. The results show that, compared to pure Pebax 1657 membranes, the doping of biochar enhanced the CO2 separation performance of MMMs. Additionally, the CO2 separation performance increased with elevating the doping rate, the best performance was achieved at a doping ratio of 4 wt%. The optimal CO2 permeability and selectivity of MMMs were 125.7 Barrer and 81.78, respectively, which separately improved 69% and 34% compared to pure Pebax 1657 membranes. Biochar-doped Pebax 1657 mixed matrix membranes exhibit excellent CO2 separation performance.展开更多
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
我国是农业大国,作为农业生产中的副产物,秸秆年产量巨大,提高秸秆的高值化利用将有利于农业生产的可持续发展。本研究以小麦秸秆为原材料制备了秸秆生物炭,使用小麦秸秆生物炭和Pebax 1657制备了混合基质膜,研究了该混合基质膜分离CO2...我国是农业大国,作为农业生产中的副产物,秸秆年产量巨大,提高秸秆的高值化利用将有利于农业生产的可持续发展。本研究以小麦秸秆为原材料制备了秸秆生物炭,使用小麦秸秆生物炭和Pebax 1657制备了混合基质膜,研究了该混合基质膜分离CO2的性能。研究表明,小麦秸秆生物炭具有高比表面积、丰富的微孔结构以及较为丰富的官能团。Pebax 1657中掺杂4 wt%小麦秸秆生物炭所制备的混合基质膜具有最佳的CO2分离性能,CO2分离渗透系数和选择性分别为106.5 Barrer和74.8,相比未掺杂前的纯Pebax 1657膜分别提升了34.0%和18.0%。China is an agricultural country, and straw, as a by-product of agricultural production, has a substantial annual output. Enhancing the high-value utilization of straw will contribute to the sustainable development of agricultural production. In this study, wheat straw biochar was prepared from wheat straw, and a mixed matrix membrane was prepared with wheat straw biochar and Pebax 1657. The performance of mixed matrix membranes for separating CO2 was investigated. The results indicated that wheat straw biochar has high specific surface area, rich microporous structure, and abundant functional groups. The mixed matrix membrane prepared with 4 wt% wheat straw biochar doped in Pebax 1657 exhibited the best CO2 separation performance. The CO2 separation permeation coefficient and selectivity were 106.5 Barrer and 74.8, respectively, which were 34.0% and 18.0% higher than the pure Pebax 1657 membrane before doping, respectively.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
文摘随着人类社会发展,CO2的过量排放造成了温室效应的加剧。我国作为农业大国,秸秆产量巨大但资源化利用水平不高。本文以玉米秸秆为原材料制备了生物炭,掺入Pebax 1657中制成混合基质膜(MMMs)用于CO2分离纯化和玉米秸秆高价值利用。结果表明,与纯Pebax 1657膜相比,生物炭填料的掺入提升了MMMs的性能,且随着掺杂比的提升气体分离性能呈现上升趋势。在掺杂比为4 wt%时性能最佳。玉米秸秆生物炭最佳CO2渗透系数和选择性分别为125.7 Barrer和81.78,相比纯Pebax 1657膜提升了69%和34%。生物炭掺杂Pebax 1657混合基质膜具有良好的分离CO2性能。With the development of human society, the excessive emission of CO2 has exacerbated the greenhouse effect. As a large agricultural country, straw production of China is huge, but its resource utilization level remains low. In this study, biochar was prepared from corn stalk, and then dopped into Pebax 1657 to produce mixed matrix membranes (MMMs), the obtained MMMs was used for CO2 separation from gas mixture. The results show that, compared to pure Pebax 1657 membranes, the doping of biochar enhanced the CO2 separation performance of MMMs. Additionally, the CO2 separation performance increased with elevating the doping rate, the best performance was achieved at a doping ratio of 4 wt%. The optimal CO2 permeability and selectivity of MMMs were 125.7 Barrer and 81.78, respectively, which separately improved 69% and 34% compared to pure Pebax 1657 membranes. Biochar-doped Pebax 1657 mixed matrix membranes exhibit excellent CO2 separation performance.
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%.
文摘我国是农业大国,作为农业生产中的副产物,秸秆年产量巨大,提高秸秆的高值化利用将有利于农业生产的可持续发展。本研究以小麦秸秆为原材料制备了秸秆生物炭,使用小麦秸秆生物炭和Pebax 1657制备了混合基质膜,研究了该混合基质膜分离CO2的性能。研究表明,小麦秸秆生物炭具有高比表面积、丰富的微孔结构以及较为丰富的官能团。Pebax 1657中掺杂4 wt%小麦秸秆生物炭所制备的混合基质膜具有最佳的CO2分离性能,CO2分离渗透系数和选择性分别为106.5 Barrer和74.8,相比未掺杂前的纯Pebax 1657膜分别提升了34.0%和18.0%。China is an agricultural country, and straw, as a by-product of agricultural production, has a substantial annual output. Enhancing the high-value utilization of straw will contribute to the sustainable development of agricultural production. In this study, wheat straw biochar was prepared from wheat straw, and a mixed matrix membrane was prepared with wheat straw biochar and Pebax 1657. The performance of mixed matrix membranes for separating CO2 was investigated. The results indicated that wheat straw biochar has high specific surface area, rich microporous structure, and abundant functional groups. The mixed matrix membrane prepared with 4 wt% wheat straw biochar doped in Pebax 1657 exhibited the best CO2 separation performance. The CO2 separation permeation coefficient and selectivity were 106.5 Barrer and 74.8, respectively, which were 34.0% and 18.0% higher than the pure Pebax 1657 membrane before doping, respectively.
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.
