title: Anharmonic magnetic deformation of self-assembled molecular nanocapsules.
abstract: High magnetic fields were used to deform spherical nanocapsules, self-assembled from bolaamphiphilic sexithiophene molecules. At low fields the deformation--measured through linear birefringence-scales quadratically with the capsule radius and with the magnetic field strength. These data confirm a long standing theoretical prediction [W. Helfrich, Phys. Lett. A 43, 409 (1973)10.1016/0375-9601(73)90396-4], and permit the determination of the bending rigidity of the capsules as (2.6+/-0.8) x 10(-21) J. At high fields, an enhanced rigidity is found which cannot be explained within the Helfrich model. We propose a complete form of the free energy functional that accounts for this behavior, and allows discussion of the formation and stability of nanocapsules in solution.
authors.affiliation: Institute for Molecules and Materials, Radboud University Nijmegen, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands.
authors.forename: O V
authors.initials: OV
authors.lastname: Manyuhina
authors.forename: I O
authors.initials: IO
authors.lastname: Shklyarevskiy
authors.forename: P
authors.initials: P
authors.lastname: Jonkheijm
authors.forename: P C M
authors.initials: PC
authors.lastname: Christianen
authors.forename: A
authors.initials: A
authors.lastname: Fasolino
authors.forename: M I
authors.initials: MI
authors.lastname: Katsnelson
authors.forename: A P H J
authors.initials: AP
authors.lastname: Schenning
authors.forename: E W
authors.initials: EW
authors.lastname: Meijer
authors.forename: O
authors.initials: O
authors.lastname: Henze
authors.forename: A F M
authors.initials: AF
authors.lastname: Kilbinger
authors.forename: W J
authors.initials: WJ
authors.lastname: Feast
authors.forename: J C
authors.initials: JC
authors.lastname: Maan