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Catalytic combustion of dimethyl ether (DME) over hexaaluminate catalyst BaNi0.2Mn0.8Al11O19-δ has been investigated. The catalysts were prepared with the sol-gel method and reverse microemulsion method respectively and characterized by thermogravimetry-differential thermal analysis, X-ray diffraction and transimission electron microscope. It was found that the formation of Mn, Ni modified hexaaluminate was a relatively slow process via two solid state reactions and spinel structure was a transition phase. At the same calcined temperature and time, the catalyst prepared with the reverse microemulsion method could form the hexaaluminate phase more easily than that prepared with the sol-gel method. The catalyst BaNi0.2Mn0.8Al11O19-δ prepared with the reverse micro-emulsion method appeared a plate-like morphology, while it appeared a needle-like morphology when using the sol-gel method. The catalytic activities of catalysts BaNi0.2Mn0.8Al11O19-δ prepared with two different methods for DME combustion were tested. It showed that catalyst prepared with the reverse microemulsion method had better catalytic activity, i.e. T10% of DME had decreased by 45℃, about 90% conversion of diemthyl ether at 380℃. 相似文献
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采用自制的有机硅抗菌剂(SSB)和羟丙基纤维素(HPC)反应,获得了抗菌改性的羟丙基纤维素(m-HPC),并用傅里叶变换红外光谱(FTIR)、X射线光电子能谱(XPS)、热失重分析(TG)等方法表征了其结构和热稳定性,采用抑菌圈法初步研究了m-HPC的抗菌性能。FTIR和XPS研究表明,SSB成功的接枝到HPC上。由于SSB的热分解温度低于HPC,导致经SSB抗菌改性的m-HPC的热分解温度(260℃)要低于HPC的起始分解温度(304℃),但不影响m-HPC的正常使用。抑菌圈试验表明,经抗菌改性的m-HPC具有较好的抗菌能力,在化妆品、食品和医药等领域存在潜在的应用价值。 相似文献
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在正庚烷、曲拉通、正辛醇和水按一定比例组成的反相微乳体系中制备了六铝酸盐LaMAl11O19-δ(M=Ni、Cu、Co、Mn和Fe),并采用XRD对该催化剂的晶相进行分析,考察不同焙烧时间和引入不同金属离子对催化剂晶相结构和热稳定性的影响。结果表明,La作为镜面离子的六铝酸盐催化剂LaMAl11O19-δ的最佳焙烧条件是1050℃焙烧4h,Mn和Fe作为活性组分掺入的六铝酸盐具有较好的热稳定性。进一步考察催化剂LaMAl11O19-δ对二甲醚催化燃烧反应。结果表明,催化剂LaMAl11O19-δ产生了催化活性,使二甲醚起燃温度和完全燃烧转化温度均比没加催化剂时降低,起燃温度为170℃,430℃时有90%的燃烧转化率。研究还对反相微乳液的回收利用进行了初步探讨,在回收的反相微乳液中制备的催化剂依然有较好的热稳定性和催化活性。 相似文献
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以环境友好的水性聚氨酯(WPU)为基体,以炭黑(CB)为导电填料,采用乳液共混法制备了低逾渗值的炭黑/水性聚氨酯(CB/WPU)导电复合材料,研究其在不同有机蒸汽环境中的气敏响应性能.研究发现,CB/WPU复合材料对有机溶剂蒸汽的气敏响应速率快,当复合材料置于饱和有机溶剂蒸汽环境时,电阻迅速增大,60 s左右电阻即可达到最大值,然后趋于稳定值;当复合材料转移到干燥空气中时,电阻急剧下降,直到回复初始电阻值.另外,CB/WPU复合材料具有广谱的气敏响应特征,表现为对极性和非极性有机溶剂蒸汽均呈现较大的气敏响应度.从而表明,CB/WPU复合材料是一种气敏响应度大、响应速度快、具有广谱气敏响应性能等综合性能优异的气敏导电复合材料. 相似文献