Polyurea-functionalized multiwalled carbon nanotubes: synthesis, morphology, and Raman spectroscopy
Chao Gao1, Yi Zheng Jin, Hao Kong
1College of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, People's Republic of China. chaogao@sjtu.edu.cn
The Journal of Physical Chemistry. B
|July 21, 2006
Summary
Researchers developed an in situ polycondensation method to graft polymers like polyureas onto multiwalled carbon nanotubes (MWNTs). This technique allows control over polymer quantity and results in functionalized MWNTs with unique self-assembled structures.
Area of Science:
- Materials Science
- Polymer Chemistry
- Nanotechnology
Background:
- Multiwalled carbon nanotubes (MWNTs) possess unique properties but require surface functionalization for advanced applications.
- Grafting polymers onto MWNTs can tailor their characteristics for nanocomposite development.
Purpose of the Study:
- To develop an in situ polycondensation method for functionalizing MWNTs with linear or hyperbranched polymers.
- To control the amount of grafted polymer by adjusting monomer feed ratios.
- To characterize the resulting polymer-functionalized MWNTs and their properties.
Main Methods:
- Oxidation of MWNTs to MWNT-COOH, followed by conversion to MWNT-COCl.
- Reaction with 1,6-diaminohexane to form amino-functionalized MWNTs (MWNT-NH2).
- In situ polycondensation of diisocyanate and 1,6-diaminohexane in the presence of MWNT-NH2 to form polyurea-coated MWNTs.
- Characterization using FTIR, NMR, Raman, confocal Raman, TEM, EDS, and SEM.
Main Results:
- Successful grafting of polyureas, polyurethanes, and poly(urea-urethane) onto MWNTs.
- Controlled polymer grafting by adjusting monomer feed ratios.
- Polyurea-coated MWNTs exhibited self-assembled flat- or flower-like morphologies.
- Significant attenuation of MWNT D and G bands in Raman spectra after polymer grafting.
Conclusions:
- The in situ polycondensation approach is effective for creating polymer-functionalized MWNTs.
- The grafted polymer structure significantly influences the Raman signals of the functionalized MWNTs.
- The developed method offers a route to tailor MWNT properties for specific applications.
