权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Molecular Assemblies Confined in a Controlled Angstrom-Range Solid Space

限制在受控埃范围固体空间中的分子组装体

基本信息

批准号：
06403013
负责人：
KANEKO Katsumi
金额：
$ 18.11万
依托单位：
Chiba University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1996
项目状态：
已结题

项目摘要

We dispersed four kinds of graphitic angstrom-range spaces : the graphitic slit micropores of heat-treated activated carbon fibers (ACFs), graphitic films of oriented slit-micropores, point defect-induced pore spaces in C60 crystals, and micropore-donated carbon aerogels. Their atomic and pore structures were determined by X-ray diffraction and molecular probe method, respectively. The nano-oriented structure of the pore oriented graphitic film was characterized by atomic force microscopy (AFM). AFM showed that slit-pores have a considerably good mutual orientation. The fine micropore structures were determined by N_2 adsorption at 77 K and He adsorption at 4.2 K In particular, He adsorption was effective for elucidation of ultramicropore structures. The structure of H_2O and CCl_4 confined in a slit-micropore of ACFs having different widths from 0.7 nm to 1.3 nm were determined by in situ X-ray diffraction at the temperature range of -150 to 30ﾟC.The electron radial distribution function of H_2O confined in the micropore at 30ﾟC was completely different from that of bulk liquid water 30ﾟC.The structure of H_2O molecules in micropores did not change even at -150ﾟC.On the other hand, CCl_4 molecules confined in micropores of pore widths except for 1.0 nm had a liquid like structure, but ones in 1.0 nm-width pores had a plastic cystalline structure. The Grand Canonical Monte Calro simulation anticipated this structural anomaly for CCl_4 molecules in micropores of the 1.0 nm width. The activated carbon aerogels had bimodal distribution of uniform mesopores and micropores, of which pore widths can be controlled by the preparation conditions. The pore geometry could be approximated by a cylinder form. The molecular defets in C_<60> crystals could be controlled by the recrystallization and it was shown that a plenty of molecular defects form the connected micropores.

我们分散了四种石墨埃范围空间：热处理活性碳纤维（ACF）的石墨狭缝微孔、定向狭缝微孔石墨膜、C60晶体中点缺陷诱导的孔隙空间和微孔提供的碳气凝胶。分别通过X射线衍射和分子探针法测定了它们的原子和孔结构。通过原子力显微镜（AFM）对孔隙取向石墨膜的纳米取向结构进行了表征。 AFM 显示狭缝孔具有相当好的相互取向。通过77 K下的N_2吸附和4.2 K下的He吸附测定了精细的微孔结构。特别是，He吸附对于阐明超微孔结构是有效的。在-150~30℃温度范围内，通过原位X射线衍射测定了限制在0.7 nm到1.3 nm不同宽度的ACFs狭缝微孔中的H_2O和CCl_4的结构。30℃时限制在微孔中的H_2O的电子径向分布函数与30℃时本体液态水的电子径向分布函数完全不同。即使在-150℃下，微孔也没有变化。另一方面，限制在除1.0 nm以外的孔宽度的微孔中的CCl_4分子具有类液体结构，而在1.0 nm宽度的孔中的CCl_4分子则具有塑性结晶结构。 Grand Canonical Monte Calro 模拟预测了 1.0 nm 宽度微孔中 CCl_4 分子的这种结构异常。活性炭气凝胶具有均匀介孔和微孔的双峰分布，其孔径可以通过制备条件控制。孔的几何形状可以近似为圆柱体形式。 C_<60>晶体中的分子缺陷可以通过重结晶来控制，并且表明大量的分子缺陷形成了连通的微孔。