title: A reversible tube-to-rod transition in a block copolymer micelle.
abstract: A remarkable morphology transition occurs with a change in temperature for a diblock copolymer [poly(ferrocenyldimethylsilane-b-dimethylsiloxane) (PFS40-b-PDMS480, PDI = 1.01)] in n-decane solution. This polymer, which forms nanotubes at 25 degrees C, rearranges to form short dense rods when the solution is heated to 50 degrees C. When the solution is cooled to 25 degrees C, the system evolves back to nanotubes. These experiments demonstrate that both structures are dynamic and represent equilibrium states of the material. Contrast matching static light-scattering measurements on the short dense rods show that the insoluble PFS core is rigid and has a length distribution similar to that seen in electron microscopy images.
authors.affiliation: Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, Canada M5S 3H6.
authors.forename: Jose
authors.initials: J
authors.lastname: Raez
authors.forename: Juan Pablo
authors.initials: JP
authors.lastname: Tomba
authors.forename: Ian
authors.initials: I
authors.lastname: Manners
authors.forename: Mitchell A
authors.initials: MA
authors.lastname: Winnik