Document Detail

Selective dispersion of single-walled carbon nanotubes in the presence of polymers: the role of molecular and colloidal length scales.
MedLine Citation:
PMID:  15535711     Owner:  NLM     Status:  PubMed-not-MEDLINE    
Dimensionality is known to play a key role in the solution behavior of nano- and mesoparticles. In particular, the shape and the range of the attractive van der Waals interparticle potential are determined by the number of microscopic versus mesoscopic dimensions. For single-walled nanotubes (SWNTs), where two of the dimensions are nanoscopic and one is mesoscopic, the intertube attraction is relatively short ranged, albeit very steep. The very large attraction (compared to the thermal energy, K(b)T) among long SWNTs leads to aggregation at different levels and constitutes a major barrier for manipulation and utilization of SWNTs. This study demonstrates that it is possible to shape the intertube potential by decorating SWNTs with end-tethered polymers. In good solvent conditions for the polymers, entropic repulsion among the tethered chains generates a free energy barrier that prevents SWNTs from approaching the attractive part of the intertube potential. Consequentially, stable dispersions of individual, well separated SWNTs can be prepared. Investigation of different chain lengths and tethering densities of the polymers as well as the interparticle potentials for nanometric versus mesoscopic particles suggests that polymer-induced steric stabilization provides a generic method for separation of SWNTs from mixtures of colloidal species, as demonstrated experimentally.
Rina Shvartzman-Cohen; Einat Nativ-Roth; Ezhil Baskaran; Yael Levi-Kalisman; Igal Szleifer; Rachel Yerushalmi-Rozen
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Journal of the American Chemical Society     Volume:  126     ISSN:  0002-7863     ISO Abbreviation:  J. Am. Chem. Soc.     Publication Date:  2004 Nov 
Date Detail:
Created Date:  2004-11-10     Completed Date:  2004-12-28     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  7503056     Medline TA:  J Am Chem Soc     Country:  United States    
Other Details:
Languages:  eng     Pagination:  14850-7     Citation Subset:  -    
Department of Chemical Engineering, Ben Gurion University in the Negev, 84105 Beer Sheva, Israel.
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