TY - JOUR
T1 - Polyurea-functionalized multiwalled carbon nanotubes
T2 - Synthesis, morphology, and Raman spectroscopy
AU - Gao, Chao
AU - Jin, Yi Zheng
AU - Kong, Hao
AU - Whitby, Raymond L.D.
AU - Acquah, Steve F.A.
AU - Chen, G. Y.
AU - Qian, Huihong
AU - Hartschuh, Achim
AU - Silva, S. R.P.
AU - Henley, Simon
AU - Fearon, Peter
AU - Kroto, Harold W.
AU - Walton, David R.M.
N1 - Copyright:
Copyright 2011 Elsevier B.V., All rights reserved.
PY - 2005/6/23
Y1 - 2005/6/23
N2 - An in situ polycondensation approach was applied to functionalize multiwalled carbon nanotubes (MWNTs), resulting in various linear or hyperbranched polycondensed polymers [e.g., polyureas, polyurethanes, and poly(urea-urethane)-bonded carbon nanotubes]. The quantity of the grafted polymer can be easily controlled by the feed ratio of monomers. As a typical example, the polyurea-functionalized MWNTs were measured and characterized in detail. The oxidized MWNTs (MWNT-COOH) were converted into acyl chloridefunctionalized MWNTs (MWNT-COCl) by reaction with neat thionyl chloride (SOCl 2). MWNT-COCl was reacted with excess 1,6-diaminohexane, affording amino-functionalized MWNTs (MWNT-NH:). In the presence of MWNT-NH 2, the polyurea was covalently coated onto the surfaces of the nanotube by in situ polycondensation of diisocyanate [e.g., 4,4′- methylenebis(phenylisocyanate)] and 1,6-diaminohexane, followed by the removal of free polymer via repeated filtering and solvent washing. The coated polyurea content can be controlled to some extent by adjusting the feed ratio of the isocyanato and amino groups. The structure and morphology of the resulting nanocomposites were characterized by FTIR, NMR, Raman, confocal Raman, TEM, EDS, and SEM measurements. The polyurea-coated MWNTs showed interesting self-assembled flator flowerlike morphologies in the solid state. The signals corresponding to that of the D and G bands of the carbon nanotubes were strongly attenuated after polyurea was chemically tethered to the MWNT surfaces. Comparative experiments showed that the grafted polymer species and structures have a strong effect on the Raman signals of polymer-functionalized MWNTs.
AB - An in situ polycondensation approach was applied to functionalize multiwalled carbon nanotubes (MWNTs), resulting in various linear or hyperbranched polycondensed polymers [e.g., polyureas, polyurethanes, and poly(urea-urethane)-bonded carbon nanotubes]. The quantity of the grafted polymer can be easily controlled by the feed ratio of monomers. As a typical example, the polyurea-functionalized MWNTs were measured and characterized in detail. The oxidized MWNTs (MWNT-COOH) were converted into acyl chloridefunctionalized MWNTs (MWNT-COCl) by reaction with neat thionyl chloride (SOCl 2). MWNT-COCl was reacted with excess 1,6-diaminohexane, affording amino-functionalized MWNTs (MWNT-NH:). In the presence of MWNT-NH 2, the polyurea was covalently coated onto the surfaces of the nanotube by in situ polycondensation of diisocyanate [e.g., 4,4′- methylenebis(phenylisocyanate)] and 1,6-diaminohexane, followed by the removal of free polymer via repeated filtering and solvent washing. The coated polyurea content can be controlled to some extent by adjusting the feed ratio of the isocyanato and amino groups. The structure and morphology of the resulting nanocomposites were characterized by FTIR, NMR, Raman, confocal Raman, TEM, EDS, and SEM measurements. The polyurea-coated MWNTs showed interesting self-assembled flator flowerlike morphologies in the solid state. The signals corresponding to that of the D and G bands of the carbon nanotubes were strongly attenuated after polyurea was chemically tethered to the MWNT surfaces. Comparative experiments showed that the grafted polymer species and structures have a strong effect on the Raman signals of polymer-functionalized MWNTs.
UR - http://www.scopus.com/inward/record.url?scp=22444449454&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=22444449454&partnerID=8YFLogxK
U2 - 10.1021/jp051642h
DO - 10.1021/jp051642h
M3 - Article
C2 - 16852469
AN - SCOPUS:22444449454
VL - 109
SP - 11925
EP - 11932
JO - Journal of Physical Chemistry B
JF - Journal of Physical Chemistry B
SN - 1520-6106
IS - 24
ER -