通过考察水与表面活性剂的摩尔比(R),TEOS的量、氨水的量及包壳次数对基于Triton X 100/环已烷/正已醇/水反相微乳液体系制备二氧化硅纳米颗粒尺寸的影响,开展了基于反相微乳液法的尺寸可控性二氧化硅纳米颗粒制备研究.结果表明:在其他...通过考察水与表面活性剂的摩尔比(R),TEOS的量、氨水的量及包壳次数对基于Triton X 100/环已烷/正已醇/水反相微乳液体系制备二氧化硅纳米颗粒尺寸的影响,开展了基于反相微乳液法的尺寸可控性二氧化硅纳米颗粒制备研究.结果表明:在其他参数都恒定的情况下,通过改变微乳液体系中上述某一组分的量,可以在一定程度上实现二氧化硅纳米颗粒的尺寸可控性合成.首先,水与表面活性剂的摩尔比(R)对二氧化硅纳米颗粒的尺寸影响最大,随着R值的增大,颗粒的粒径逐渐减小,当R值达到18时,二氧化硅纳米颗粒的形貌变得不再是很规则的球形结构,并且分散性降低,团聚现象明显;其次是氨水的量,随着氨水量的增多,颗粒的粒径先减小,之后不再发生明显变化;另外随着包壳次数的增多,颗粒的粒径随之增大,并且颗粒之间的分散性也有所提高;但是TEOS的量对颗粒粒径的影响不明显.展开更多
Nanoparticles of BaLiF3：Er^3＋ were prepared from the quaternary microemulsions of Cetyltrim-Enthyl Ammonium Bromide （CTAB）, n-butanol, n-octane, and water, using the hydrothermal-microemulsion technique. The compl...Nanoparticles of BaLiF3：Er^3＋ were prepared from the quaternary microemulsions of Cetyltrim-Enthyl Ammonium Bromide （CTAB）, n-butanol, n-octane, and water, using the hydrothermal-microemulsion technique. The complex fluorides were characterized by means of X-ray power diffraction, Environmental Scanning Electron Microscopy （ESEM）, and fluorescence spectra. The positions and intensifies of the peaks in the XRD pattern of the final products indicate the formation of BaLiF3·Er^3＋. No other peaks or impurities were detected. The average size of the nanoparticles, calculated with the Debye-Scherrer equation was 98.45 nm, which was in agreement with the result of ESEM. The infrared fluorescence spectra consisted of four peaks with a predominant peak located at 1540 nm.展开更多
Nanocrystalline indium oxide powders were prepared by microemulsion and then Y2O3 and Nd2O3 doped In2O3 were synthesized separately by impregnation and chemical co-deposition. The structure and morphology were charact...Nanocrystalline indium oxide powders were prepared by microemulsion and then Y2O3 and Nd2O3 doped In2O3 were synthesized separately by impregnation and chemical co-deposition. The structure and morphology were characterized by XRD and TEM, respectively. Gas sensing properties were tested at static state. The results show that homogeneous indium oxide nanopowder with main grain size of 20 nm can be obtained from microemulsion after sintered at 600 ℃ for 1 h. Pure indium oxide gas sensor has higher sensitivity to gasoline than that to ethanol, HCHO, C6H6, NH3, C4H10, but the selectivity is not as well as sensitivity.展开更多
文摘通过考察水与表面活性剂的摩尔比(R),TEOS的量、氨水的量及包壳次数对基于Triton X 100/环已烷/正已醇/水反相微乳液体系制备二氧化硅纳米颗粒尺寸的影响,开展了基于反相微乳液法的尺寸可控性二氧化硅纳米颗粒制备研究.结果表明:在其他参数都恒定的情况下,通过改变微乳液体系中上述某一组分的量,可以在一定程度上实现二氧化硅纳米颗粒的尺寸可控性合成.首先,水与表面活性剂的摩尔比(R)对二氧化硅纳米颗粒的尺寸影响最大,随着R值的增大,颗粒的粒径逐渐减小,当R值达到18时,二氧化硅纳米颗粒的形貌变得不再是很规则的球形结构,并且分散性降低,团聚现象明显;其次是氨水的量,随着氨水量的增多,颗粒的粒径先减小,之后不再发生明显变化;另外随着包壳次数的增多,颗粒的粒径随之增大,并且颗粒之间的分散性也有所提高;但是TEOS的量对颗粒粒径的影响不明显.
基金Project supported by the Foundation of Science and Technology Department of Jilin Province (20050507)
文摘Nanoparticles of BaLiF3：Er^3＋ were prepared from the quaternary microemulsions of Cetyltrim-Enthyl Ammonium Bromide （CTAB）, n-butanol, n-octane, and water, using the hydrothermal-microemulsion technique. The complex fluorides were characterized by means of X-ray power diffraction, Environmental Scanning Electron Microscopy （ESEM）, and fluorescence spectra. The positions and intensifies of the peaks in the XRD pattern of the final products indicate the formation of BaLiF3·Er^3＋. No other peaks or impurities were detected. The average size of the nanoparticles, calculated with the Debye-Scherrer equation was 98.45 nm, which was in agreement with the result of ESEM. The infrared fluorescence spectra consisted of four peaks with a predominant peak located at 1540 nm.
文摘Nanocrystalline indium oxide powders were prepared by microemulsion and then Y2O3 and Nd2O3 doped In2O3 were synthesized separately by impregnation and chemical co-deposition. The structure and morphology were characterized by XRD and TEM, respectively. Gas sensing properties were tested at static state. The results show that homogeneous indium oxide nanopowder with main grain size of 20 nm can be obtained from microemulsion after sintered at 600 ℃ for 1 h. Pure indium oxide gas sensor has higher sensitivity to gasoline than that to ethanol, HCHO, C6H6, NH3, C4H10, but the selectivity is not as well as sensitivity.
