title: Density fluctuations and phase transitions of ferroelectric polymer nanowires.
abstract: Phase transitions of polymeric materials are accompanied by changes in density as a function of temperature. Being able to measure these changes in polymeric systems in one, two or three dimensions on the nanoscopic length-scale is a challenge, but it would provide a simple route to assess phase transitions in nanoscopically confined systems. It is shown that the measurement of the dielectric permittivity in the high frequency limit (in spectral regions not affected by dielectric dispersions) offers an effective and very sensitive means to assess density fluctuations, and hence phase transitions, in nanoscopic systems. The sensitivity of this approach is demonstrated by assessing the phase transition behavior of ferroelectric polymer nanowires confined within alumina membranes. No significant shifts in the Curie transition are observed down to pore diameters as small as 15 nm.
authors.affiliation: Department of Polymer Science and Engineering University of Massachusetts Amherst, MA 01003, USA.
authors.forename: Anatoli
authors.initials: A
authors.lastname: Serghei
authors.forename: Jodie L
authors.initials: JL
authors.lastname: Lutkenhaus
authors.forename: Daniel F
authors.initials: DF
authors.lastname: Miranda
authors.forename: Kathleen
authors.initials: K
authors.lastname: McEnnis
authors.forename: Friedrich
authors.initials: F
authors.lastname: Kremer
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Russell
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry; D053770:Nanowires / Q000737:chemistry*; D044367:Phase Transition; D011108:Polymers / Q000737:chemistry*; D013696:Temperature; D013816:Thermodynamics
chemical_list: D011108:Polymers; D000537:Aluminum Oxide