由火焰水解产生的的结构和相变
Jamal Nasir1, Franz Schmidt2, Frank Menzel2
1University of Siegen, Faculty IV: School of Science and Technology, Department of Chemistry and Biology, Inorganic Materials Chemistry and Center of Micro- and Nanochemistry and Engineering (Cμ), Adolf-Reichwein-Straße 2, D-57076 Siegen, Germany. gunnej@chemie.uni-siegen.de.
通过AlCl3燃烧合成的化纳米颗粒表现出从-到三角和-的相变化. 三角相表现出一个有序的结构,特定的协调受到粒子表面积和水吸附的影响.
科学领域:
- 材料科学 材料科学 材料科学
- 纳米技术 纳米技术
- 固态化学 固态化学
背景情况:
- 纳米粒子在各种工业应用中至关重要.
- 了解合成过程中的相变化和结构性质对于控制材料性能至关重要.
- 通过燃烧产生的化具有独特的纳米级性能.
研究的目的:
- 为了描述由AlCl3燃烧产生的烟纳米颗粒.
- 为了研究从玛到三角形和甲的相位演变.
- 阐明不同相中的的结构和协调环境.
主要方法:
- 从化 (AlCl3) 中燃烧合成烟.
- 使用粉末X射线衍射 (XRD),27Al固态核磁共振 (NMR) 和传输电子显微镜 (TEM) 的表征.
- 使用Brunauer-Emmett-Teller (BET) 方法对特定表面积的分析.
主要成果:
- 产生了具有30至220m2/g的特定表面积的纳米粒子.
- 在合成过程中,米转化为米和米的混合物.
- 在高表面积的-中观察到五坐标,部分在表面.
- 水吸附可逆地增加了颗粒表面的协调.
- 27Al MQMAS NMR揭示了8个晶体位点在delta和theta-alumina中,其中4个独特的AlO4位点是独一无二的.
- 确定了三角形-相作为一个有序的结构.
结论:
- 合成过程产生不同表面积和不同相组合的纳米粒子.
- 证实了三角相的结构顺序,为其形成机制提供了洞察力.
- 协调对表面积和吸附水很敏感,影响表面的特性.
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