Non-invasive and Rapid Characterization of Interaction of Water with Carbon Nanotubes using Low-field TD-NMR
X. Tombokan, S. Ghosh, P. Hari
Bruker Corporation, US
Keywords: carbon nanotube (CNT), transport, time-domain NMR
Abstract:Carbon nanotubes (CNTs) are increasingly being investigated for various novel applications, due to their unique properties. One of the interesting properties of CNT is its very high efficiency of water transport. This is very attractive to the research in development of nanofilters and nanosyringes for drug delivery. The evidence that transport rate exhibited by these CNTs exceed the continuum mechanics based predictions, provides motivation for fundamental study of how water molecules interact with the CNT surfaces and thus changes its own mobility. High resolution NMR is being utilized by various groups to investigate this interaction, mainly using magic angle spinning. TD-NMR (time-domain nuclear magnetic resonance) using a small bench-top instrument is a powerful tool to rapidly quantify the mobility of water, with easy operation. This technique has been utilized to quantify water mobility and interaction in wide range of matrices. Hence, TD-NMR is adopted in this research to investigate the status of water inside and outside the single-walled CNTs, through a well-designed set of experiments utilizing opening and closing of CNTs, followed by continual desorption. The presentation will provide a brief introduction to TD-NMR techniques used in measuring fluid transport in functionalized and pure carbon nanotubes. We will elaborate on the results from the water-CNT interaction experiments and how it relates to the observed transport behavior. In addition, we will also discuss other active research, where TD-NMR is utilized to investigate materials at micro- and nano-scale.