Showing papers by "Yue Wu published in 2004"
TL;DR: In this article, the authors used a standard inversion-recovery pulse segment as a filter for different components and a composite pulse to measure only the decay of the selected component.
11 citations
01 Mar 2004
TL;DR: In this article, it was shown that exposure to oxygen has no effect on methane and ethane endohedral adsorption in single-walled carbon nanotubes (SWNTs) and the average exchange time between molecules adsorbed inside SWNTs and free gas molecules outside was estimated to be on the order of 80 ms.
Abstract: Adsorption isotherms of methane and ethane in single-walled carbon nanotubes (SWNTs) were measured by 1 H nuclear magnetic resonance (NMR) at room temperature. It is shown that the interior of SWNTs becomes available formethane and ethane adsorption after cutting of SWNTs. Such endohedral adsorption dominates methane and ethane adsorption in SWNTs, at least below 1 MPa. The average exchange time between molecules adsorbed inside SWNTs and free gas molecules outside was estimated to be on the order of 80 ms. It is shown that exposure to oxygen has no effect on methane and ethane endohedral adsorption in SWNTs, suggesting that the adsorption energy of oxygen molecules inside SWNTs is small compared to that of methane. 1 3 C NMR indicates that under atmospheric pressure and room temperature helium atoms could access the interstitial sites of SWNT bundles whereas H 2 , CO 2 , and N 2 molecules could not.
1 citations