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La2O3薄膜材料应用广泛,而制备La2O3薄膜的前驱体合成面临着挑战,多数现有前驱体热稳定性差、合成路线复杂或者成本高等问题。因此,本文报道了混配型和均配型的胍基、脒基镧配合物二(N,N′-二异丙基-甲胺基胍基)一(N,N′-二异丙基戊基脒基)合镧(配合物1)和三(N,N′-二异丙基-甲胺基胍基)合镧(配合物2),通过1H NMR,13C NMR表征结构;通过热重分析(TGA)研究所有配合物的热稳定性和挥发性。结果表明:配合物1在加热至170.0℃时,其蒸气压会急剧上升;在202.0℃能产生1.0 Torr的蒸气压;在260.0℃以下该配合物有良好的热稳定性。以上数据说明:该配合物比较好地满足CVD工艺条件,是一种潜在的化学气相沉积前驱体;通过CVD技术,在源加热温度210℃、沉积温度为260.0℃、沉积时间为10.0 min的条件下得到约11.9 nm薄膜,SEM和XPS分析了薄膜的形貌和成分,实验结果表明沉积的纳米薄膜为高纯的La2 相似文献
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以三氯化硼和甲基氢二氯硅烷为原料,采用共氨解的方式合成了聚硼硅氮烷前驱体,并采用核磁共振波谱仪、傅里叶红外光谱仪、差式扫描量热仪、热重分析仪、光电子能谱、网络矢量分析仪等仪器对前驱体及其热解产物进行了表征。前驱体在1000 oC、氮气气氛下热解的陶瓷产率为71.1 %。在氨气气氛下热解可以有效降低热解产物中的碳含量,聚硼硅氮烷在900 oC氨气气氛下热解产物的碳含量低于1 %,并且该热解产物具有高的结晶温度、良好的抗氧化性能和介电性能,有望用于耐高温陶瓷基透波复合材料。 相似文献
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2,3,6,2',3',4',6'-七-O-乙酰基-β-乳糖基异硫氰酸酯(1)分别与2-氨基-4/6-取代苯并噻唑2a~2e反应, 制得糖基硫脲3a~3e, 将其在HgCl2作用下与伯胺反应, 制得一系列新化合物N-烷基/芳基-N'-(4/6-取代-苯并噻唑-2-基)-N'-(2,3,6,2',3',4',6'-七-O-乙酰基-β-乳糖基)胍4~6. 然后, 在CH3ONa/CH3OH作用下, 脱乙酰基得含苯并噻唑基的乳糖基胍类化合物7~9. 所有新化合物的结构均经IR, 1H NMR, MS谱和元素分析证实, 所得产物均为b-构型. 对代表性化合物的生物活性测试结果表明, 乳糖基胍类化合物对HIV-1蛋白酶、血管紧张素转化酶(ACE)的抑制活性较差. 相似文献
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将2,3,4,6-四-O-乙酰基-β-D-吡喃葡萄糖基异硫氰酸酯(1)与2-氨基-4/6-取代-苯并噻唑(2a~2e)反应, 生成糖基硫脲衍生物(3a~3e), 再在伯胺存在下经氯化汞脱硫, 得到一系列新的多乙酰基胍基糖苷类化合物(4a~4d, 5a~5d, 6a~6d, 7a~7d), 糖基的保护基团在甲醇钠/甲醇条件下脱除. 所有新化合物的结构均经IR, 1H NMR, MS谱和元素分析证实, 所得产物均为β-构型. 生物活性测试结果表明, 化合物4c, 6c, 8b, 8c等对HIV-1蛋白酶表现出了较高的抑制活性; 化合物7c具有抗流感乙型病毒活性; 化合物5e, 7c, 7d等对血管紧张素转化酶具有抑制活性. 相似文献
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稀土铝酸盐蓝色荧光粉前驱体的制备及其应用 总被引:9,自引:0,他引:9
以硫酸铝铵和碳酸氢铵为原料,制备了结晶碳酸铝铵,用IR,XRD,DTA-TG等手段研究了结晶碳酸铝铵在煅烧过程中的相变和热分解机理,并考察了煅烧过程中的粒度和比表面变化以及煅烧产物的外观形貌,结果表明:在煅烧过程中结晶碳酸铝铵首先分解为无定型氧化铝,并依次从无定型Al2O3-γ-Al2O3-κ-Al2O3,δ-Al2O3,τ-Al2O3-α-Al2O3,τ-Al2O3-α-Al2O3转变,比表面在600℃之前是随温度升高而增大,600摄氏度之后则下降,而粒度变化在900摄氏度之前随温度升高而降低,900摄氏度之后则增大,煅烧产物为粒度在2-3um的片状结晶氧化铝,用该氧化铝所合成的稀土铝酸盐蓝粉,晶相纯,发光强度高,且粒度小,可以满足不球磨蓝色荧光粉的基本要求。 相似文献
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Thermogravimetric Study of Volatile Precursors For Chemical Thin Film Deposition. Estimation of vapor pressures and source temperatures 总被引:1,自引:0,他引:1
Niskanen A. Hatanpää T. Ritala M. Leskelä M. 《Journal of Thermal Analysis and Calorimetry》2001,65(3):955-964
Normal pressure thermogravimetry (TG) measurements were used to study the sublimation behavior of several volatile metal compounds,
used as metal precursors in thin film fabrication by chemical vapor phase methods, like atomic layer deposition (ALD) and
chemical vapor deposition (CVD). The results indicated that dynamic TG measurements may be used to find correct source temperatures
to be used in an ALD reactor: a good correlation between the source temperatures used in ALD and temperatures corresponding
to mass losses of 10 and 50% in TG was verified. It was also found that isothermal TG measurements offer a simple way for
the vapor pressure measurements which otherwise are not trivial for solids with only moderate volatility.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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Silicon carbide nanotubes (SiCNTs) were prepared by chemical vapor deposition (CVD). Methyltrichlorosilane (MTS) was selected as the SiC gaseous source and, ferrocence and thiophene as the catalyst and the cocatalyst, respectively. The influences of pyrolysis temperature, the content of catalyst and the cocatalyst, and the mole ratio between H2 and MTS, on the shape of the pyrolysis products were investigated, respectively. The products were characterized by SEM, EDX, XRD and HRTEM, respectively. Novel type of multi-walled SiCNTs, with 30~80 nm and 15~20 nm outer and inner diameters, respectively, were observed. 相似文献
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Qun Zeng Zhenhua Li Yuhong Zhou 《天然气化学杂志》2006,15(3):235-246
Owing to the unique structure, the superior physical and chemical properties, the super strong mechanical performances, and so on, carbon nanotubes have attracted the attention of researchers all over the world. In this article, the basic properties and the main production processes of carbon nanotubes are introduced in brief, and the progress of applied research for carbon nanotubes is reviewed. 相似文献
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Ufuk Atamtürk Veronika Brune Shashank Mishra Sanjay Mathur 《Molecules (Basel, Switzerland)》2021,26(17)
Extraordinary low-temperature vapor-phase synthesis of SnS thin films from single molecular precursors is attractive over conventional high-temperature solid-state methods. Molecular-level processing of functional materials is accompanied by several intrinsic advantages such as precise control over stoichiometry, phase selective synthesis, and uniform substrate coverage. We report here on the synthesis of a new heteroleptic molecular precursor containing (i) a thiolate ligand forming a direct Sn-S bond, and (ii) a chelating O^N^N-donor ligand introducing a “launch vehicle”-effect into the synthesized compound, thus remarkably increasing its volatility. The newly synthesized tin compound [Sn(SBut)(tfb-dmeda)] 1 was characterized by single-crystal X-ray diffraction analysis that verified the desired Sn:S ratio in the molecule, which was demonstrated in the direct conversion of the molecular complex into SnS thin films. The multi-nuclei (1H, 13C, 19F, and 119Sn) and variable-temperature 1D and 2D NMR studies indicate retention of the overall solid-state structure of 1 in the solution and suggest the presence of a dynamic conformational equilibrium. The fragmentation behavior of 1 was analyzed by mass spectrometry and compared with those of homoleptic tin tertiary butyl thiolates [Sn(SBut)2] and [Sn(SBut)4]. The precursor 1 was then used to deposit SnS thin films on different substrates (FTO, Mo-coated soda-lime glass) by CVD and film growth rates at different temperatures (300–450 °C) and times (15–60 min), film thickness, crystalline quality, and surface morphology were investigated. 相似文献
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Hong Bo CHEN Jing Dong LIN Jun YI Yun CAI Guang WEI Yin Zhong LIN Dai Wei LIAO * Department of Chemistry Department of Oceanography State Key Lab of Physical Chemistry on Solid Surfaces Institute of Physical Chemistry 《中国化学快报》2001,(12)
The preparation of silicon nanotubes is a subject of great importance for both the theoretical and experimental work in the nanotube research field since it could lead to a wealth of new physics and chemistry because of the unique properties of silicon as compared with its carbon analogue. Some structures of nanoscale silicon and silicon composites, such as silicon nanowire1, silicon nano-clusters2 and SiC nanorods3 have been discovered and investigated. The silicon nanotubes, however, have … 相似文献
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Dr. Qiao Chen Xin Yi Meirong Huang Wenjia Wu Qiyang Song Changjiang Nie Prof. Shun Wang Prof. Hongwei Zhu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(33):7463-7469
Precursors and catalysts play vital roles in chemical reactions. Considerable efforts have been devoted to the investigation of catalysts for graphene growth by chemical vapor deposition in recent years. However, there has been little research on precursors because of a lack of innovation in term of creating a controllable feeding method. Herein, we present a novel sustained and controlled release approach, and develop a convenient, safe, and potentially scalable feeding system with the assistance of matrix materials and a simple portable feeder. As a result, a highly volatile liquid precursor can be fed accurately to grow large-area, uniform graphene films with optimal properties. This feeding approach will further benefit the synthesis of other two-dimensional materials from various precursors. 相似文献
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硅纳米线阵列是利用太阳能解决能源和环境问题的重要材料,然而,可用于柔性器件和生物相容性器件的柔性硅纳米线阵列的制备方法非常有限。本文通过化学气相沉积,以及高分子转移的方法,成功制备了具有不同高分子层厚度的柔性硅纳米线阵列,并研究了高分子层厚度对柔性硅纳米线阵列光催化性能的影响。结果表明,高分子层厚度越小,柔性硅纳米线阵列的光催化性能越强。因此,利用本文提出的制备方法得到的高分子层厚度低至5 μm的柔性硅纳米线阵列,具有作为高效柔性太阳能电池和全光解水系统光电极的潜力。同时,该研究结果也为设计具有高效光能转换能力的柔性纳米线阵列提供了重要依据。 相似文献
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Quasi-periodically intermittent hollow-cavity-stacked one-dimensional carbon nanostructures were obtained by microwave plasma chemical vapor deposition from the mixture of CH4 and N2 on Fe/γ-Al2O3 catalyst. This structure was characterized by transmission electron microscope (TEM), high-resolution TEM and X-ray energy dispersive spectral analysis. The results indicate that the trace impurity of nitrogen might account mainly for the formation of these novel nanostructures. The structural units in these one-dimensional carbon nanostructures are full of nanocavities, which may be of potential importance in hydrogen storage. 相似文献