Preparation of Metal Films Containing Nano-Size Channels

含有纳米尺寸通道的金属薄膜的制备

基本信息

批准号：
13650713
负责人：
TANIMOTO Hisanori
金额：
$ 1.28万
依托单位：
University of Tsukuba
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2003
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13650713/
关键词：
nanocrystalline materials porous materials interface effect nano-filter gas-deposition method metallic membrane

项目摘要

Metallic films prepared by consolidation of ultra-fine particles may contain nano-size pores and channels along the grain boundaries, and they are expected for the application to metallic nano-filters or catalytic materials. In order to prepare the metallic films containing nano-size channels, low-density nanocrysatlline (n-) Au films were prepared by applying the gas-deposition method. The density of n-Au films prepared was about 93 〜 98 % of the bulk Au density and the mean grain size about 10 〜 20 nm. Some of the n-Au films showed gas-permeability of about 10^<-11> mol m/(Pa m^2 s) for helium gas at room temperature, that is larger by mare than two order than those of the plastic films such as the natural rubber. Pore-like dimples with the diameter of 〜 20 nm were found in the STM surface images of n-Au films with the high gas-permeability. The gas-permeability of the n-Au films was decreased in proportional to the square root of the molecular weight of gas. These observations suggest that the gas-permeability of the present n-Au films is due to the channels with the diameter of 〜 20 nm and the area fraction of 〜 1%, where the gas atoms are assumed to permeate the n-Au films as a molecular flow. Further, the n-Au films with the relative density of 〜 95 % showed a high thermal stability, i.e. the mean grain size remained to be about 40 nm after the annealing at 1200 K for 1.8 ks. It suggests that the nano-channels or pores in the specimens play an important role on the high-thermal stability of the present n-Au films

通过超细颗粒固结制备的金属薄膜可能在晶界上含有纳米尺寸的孔和通道，它们有望应用于金属纳米过滤器或催化材料，以制备含有纳米尺寸的金属薄膜。采用气相沉积法制备了低密度纳米晶（n-）Au薄膜，所制备的n-Au薄膜的密度约为Au体积密度和平均密度的93％至98％。一些n-Au膜的晶粒尺寸为约10至20nm，在室温下对于氦气表现出约10^<-11>molm/(Pam^2s)的气体渗透率，这比n-Au膜大很多。在具有高透气性的 n-Au 薄膜的 STM 表面图像中发现了直径约为 20 nm 的孔状凹坑，比天然橡胶等塑料薄膜高出两个数量级。 n-Au 薄膜的透气性与气体分子量的平方根成正比，这些观察结果表明，当前 n-Au 薄膜的透气性是由于直径为 ~ 的通道造成的。 20 nm，面积分数约为 1%，其中气体原子被假定为以分子流形式渗透到 n-Au 薄膜中，此外，相对密度约为 95% 的 n-Au 薄膜表现出较高的热稳定性，即在 1200 K 退火 1.8 ks 后，平均晶粒尺寸仍保持在 40 nm 左右，这表明样品中的纳米通道或孔对当前 n-Au 薄膜的高热稳定性起着重要作用。