NER: Fabrication of an Integrated Structure of 3D Macroporous Silica and Carbon Nanotubes

Stevens Institute Of Technology, Hoboken NJ

Investigators

Abstract

PROPOSAL NO.: CTS-0210195 PRINCIPAL INVESTIGATORS: HENRY DU INSTITUTION: STEVENS INSTITUTE OF TECHNOLOGY ABSTRACT: 3D porous materials with highly ordered interconnecting pores and carbon nanotubes are at the frontier of science and engineering. This Nanoscale Exploratory Research (NER) proposal aims to integrate these two areas by exploring aligned growth of carbon nanotubes on the pore walls of high-surface-area microporous silica. Several tasks are being pursued to achieve the proposed goal. Specifically, equilibrium-driven colloidal self-assembly processes as well as colloidal epitaxy on ultra-fine TEM grids is being used to obtain opals of polystyrene spheres as structural templates. A sol-gel route is being employed for effective infiltration of the templates to produce inverted silica opals upon subsequent thermal decomposition of the template opals. A synthesis strategy is also being developed for deposition of uniform, nanometer-sized, catalytic cobalt particles on the pore walls. The approach is being used to grow aligned carbon nanotubes on the pore walls throughout the volume of the macroporous silica using plasma-enhanced chemical vapor deposition. This project represents the first known attempt to fabricate an integrated structure composed of 3D macroporous materials and carbon nanotubes. Critical challenges are being addressed related to the deposition of cobalt particles and the controlled growth of aligned carbon nanotubes on pore walls. The integration of the two aspects of this work will yield potentially robust structures for applications where an abundance of nanotube arrays is needed for system efficiency. Such applications include entrapment of DNA and proteins, catalytic supports, desalination of seawater, and hydrogen storage for fuel cells. Knowledge generated in this investigation can be extended to the fabrication of other 3D macroporous materials, such as semiconductors. The success of the project thus offers exciting prospects for the exploration of carbon nanotubes for applications in the nanotechnology arena and across science and engineering.