Polymer/Single-Walled Carbon Nanotube Films Assembled via Donor-Acceptor Interactions and Their Use as Scaffolds for Silica Deposition

A method of stepwise assembling thin polymer/singlewalled carbon nanotube (SWCNT) films using donoracceptor interactions is demonstrated. When the affinity that amine groups have for nanotubes were utilized, films were formed by the sequential adsorption of polyethylenimine and polyallylamine followed by SWCNTs onto silicon substrates. In an effort to expand this methodology to more thermally and oxidatively stable polymer systems, the ability of the basic nitrogen of the pyridine ring to adsorb SWCNTs was also investigated. These studies demonstrated that the nonsterically hindered, parasubstituted pyridine in poly(4-vinylpyridine) (P4VP) also has an affinity for SWCNTs, thus enabling the stepwise formation of P4VP/SWCNT films. Microscopy of the films revealed that they were formed of single tubes and small bundles and that film coverage and thickness were uniform. The ability to use these films as scaffolds for the synthesis of novel hybrid structures is demonstrated by modifying the P4VP films using sol-gel chemistry.