Nanotubular Materials and Novel Phenomena Associated with Adsorbed Molecules

TECHNICAL ABSTRACT

Previous studies have shown that the structures of water inside carbon nanotubes are very different from bulk water and depend strongly on tube diameters. Recently, it was demonstrated that the enthalpy and entropy of water inside carbon nanotubes can also depend significantly on temperature leading to temperature-dependent water adsorption properties. In this project, water adsorption and dynamics in carbon nanotubes will be examined by nuclear magnetic resonance. Specifically, temperature and carbon nanotube diameter dependence of water adsorption and dynamics will be investigated. The basic knowledge and experimental approaches will also be extended to the hydration study of some model proteins. Water adsorption in seemingly hydrophobic nanostructures is an important phenomenon related to a broad range of important issues such as nanofluidics, protein hydration, and protein folding. The second type of nanotubes to be studied is titania nanotubes. The unique structure of this material leads to novel inorganic/organic structures with promising photoelectrochemical properties. This project will synthesize a variety of titania nanotubes/dye hybrid structures, characterize systematically the structures and bonding of such inorganic/organic structures and interfaces, and examine the optical and electron transfer properties. This research could have a major impact on solar fuel research and development. High school students will be involved in this nanomaterials-based solar fuel research and related topics will be incorporated in classroom teaching.

NON-TECHNICAL ABSTRACT

Water adsorption in seemingly hydrophobic nanostructures is an important phenomenon related to a broad range of important issues such as nanofluidics, protein hydration, and protein folding. Water inside carbon nanotubes provides an ideal model system for elucidating the mechanism of adsorption and dynamics of nanoconfined water by hydrophobic surfaces. Using nuclear magnetic resonance, this project will investigate systematically the effects of the carbon nanotube diameter and temperature on water adsorption and dynamics. This basic knowledge and approach will be extended to the study of protein hydration. This study could provide fundamental understanding of important phenomena from the function of engineering devices such as nanofluidics to biological systems such as enzyme activity. The understanding of the atomic structures and interfaces of titania nanotubes/organic molecule hybrids is of crucial importance for developing efficient systems for solar fuel exploration. In this project, new titania nanotube-based hybrid structures will be developed, basic optical and electronic processes will be examined, and their potentials for solar fuel production will be evaluated. This project will also have active involvement of high school students. Through course development, teaching, and summer research many high school students will be trained in using their comprehensive knowledge on materials sciences, physics, and chemistry for the development of renewable energy.