Journal
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
Volume 124, Issue 35, Pages 10381-10395Publisher
AMER CHEMICAL SOC
DOI: 10.1021/ja020349h
Keywords
-
Categories
Ask authors/readers for more resources
Block copolymers with a high asymmetry normally give spherical starlike micelles in a solvent selective for the longer block. We have discovered that samples of poly(ferrocenyldimethylsilane-b-dimethylsiloxane) (PFS-b-PDMS) with block ratios of 1:12 form nanotubes in n-hexane and n-decane, which are poor solvents for PFS. Two block copolymer samples PFS40-b-PDMS480 (M-n = 45 300, PDI = 1.01) and PFS80-b-PDMS960 (M-n = 90 500, PDI = 1.01) were synthesized by sequential anionic polymerization. When self-assembly occurs, the PFS blocks aggregate and crystallize to form a shell with a cavity in the middle of the tube, while the PDMS blocks form the Corona. The nature of these structures was elucidated by conventional transmission electron microscopy and dark-field scanning transmission electron microscopy. Time- and temperature-dependence studies revealed that a variety of morphologies are formed initially depending on the conditions of sample preparation, but most of them eventually rearrange to form nanotubules. The lengths of the tubes can be varied with time and with the choice of solvents. We have been able to grow nanotubes with lengths reaching 0.1 mm. The presence of the hollow core was confirmed by trapping tetrabutyllead in the cavity and performing energy-dispersive X-ray measurements on the resulting structure.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available