γ-Alumina Nanofibers Prepared from Aluminum Hydrate with Poly(ethylene oxide) Surfactant
γ-Alumina Nanofibers Prepared from Aluminum Hydrate with Poly(ethylene oxide) Surfactant
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DOI：
10.1021/cm010736a
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发表时间：
2002-04
影响因子：
8.6
通讯作者：
Huaiyong Zhu;J. Riches;J. Barry
中科院分区：
文献类型：
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作者：
Huaiyong Zhu;J. Riches;J. Barry
在氢氧化铝胶体中引入聚氧化乙烯表面活性剂可以有效地指导勃姆石的晶体生长和最终γ-氧化铝微晶的晶体形态。得到约3 - 4 nm厚、30 - 60 nm长的γ-氧化铝纤维状微晶。它们随机堆叠，导致纤维之间接触面积低但孔隙率非常大的结构。这种结构在加热到高温时表现出强的抗烧结性。样品在加热至1473 K后保持68 m2/g的BET表面积。表面活性剂分子形成胶束，通过氢键与氢氧化铝的胶体颗粒相互作用。这种相互作用不足以改变勃姆石的固有晶体结构，但会引起勃姆石微晶的形态及其生长的深刻变化。表面活性剂诱导的纤维形成（SIFF）过程具有不同于模板合成的特征，但在某些方面与生物素合成具有相似之处。
Introducing poly(ethylene oxide) surfactant to aluminum hydrate colloids can effectively direct the crystal growth of boehmite and the crystal morphology of final γ-alumina crystallites. Fibrous crystallites of γ-alumina about 3−4 nm thick and 30−60 nm long are obtained. They stack randomly, resulting in a structure with a low contact area between the fibers but with a very large porosity. Such a structure exhibits strong resistance to sintering when heated to high temperatures. A sample retains a BET surface area of 68 m2/g, after being heated to 1473 K. The surfactant molecules form micelles that interact with the colloid particles of aluminum hydroxide through hydrogen bonding. This interaction is not sufficient to change the intrinsic crystal structure of boehmite, but induces profound changes in the morphology of boehmite crystallites and their growth. The surfactant-induced fiber formation (SIFF) process has distinct features from templated synthesis but shows similarities in some respects to biomin...