title: Oriented polyvinylidene fluoride-trifluoroethylene (P(VDF-TrFE)) films by Langmuir-Blodgett deposition: a synchrotron X-ray diffraction study.
abstract: Langmuir-Blodgett films of polyvinylidene fluoride trifluoroethylene - P(VDF-TrFE)-copolymers possess substantially improved electrocaloric and pyroelectric properties, when compared with conventionally spin-cast films. In order to rationalize this, we prepared single-layered films of P(VDF-TrFE) (70 : 30) using both deposition techniques. Grazing incidence wide-angle X-ray scattering (GIWAXS), reveals that Langmuir-Blodgett deposited films have a higher concentration of the ferroelectric β-phase crystals, and that these films are highly oriented with respect to the substrate. Based on these observations, we suggest alternative means of deposition, which may substantially enhance the electrocaloric effect in P(VDF-TrFE) films. This development has significant implications for the potential use of P(VDF-TrFE) in solid-state refrigeration.
authors.affiliation: Department of Materials Engineering, Iowa State University, Ames, IA 50011, USA and Ames National Laboratory, Ames, IA 50011, USA. vaknin@ameslab.gov.
authors.forename: W R
authors.initials: WR
authors.lastname: Lindemann
authors.affiliation: Department of Materials Engineering, Iowa State University, Ames, IA 50011, USA and Department Bioengineering, University of Washington, Seattle, WA 98105, USA.
authors.forename: R L
authors.initials: RL
authors.lastname: Philiph
authors.affiliation: Department of Electrical & Computer Engineering, Iowa State University, Ames, IA 50011, USA.
authors.forename: D W W
authors.initials: DW
authors.lastname: Chan
authors.affiliation: Department of Electrical & Computer Engineering, Iowa State University, Ames, IA 50011, USA.
authors.forename: C T
authors.initials: CT
authors.lastname: Ayers
authors.affiliation: Department of Materials Engineering, Iowa State University, Ames, IA 50011, USA.
authors.forename: E M
authors.initials: EM
authors.lastname: Perez
authors.affiliation: Department of Materials Engineering, Iowa State University, Ames, IA 50011, USA and School of Mechanical and Materials Engineering, Washington State University, Pullman, WA 99164, USA.
authors.forename: S P
authors.initials: SP
authors.lastname: Beckman
authors.affiliation: X-Ray Science Division, Argonne National Laboratory, Argonne, Illinois, USA.
authors.forename: J
authors.initials: J
authors.lastname: Strzalka
authors.affiliation: Department of Electrical & Computer Engineering, Iowa State University, Ames, IA 50011, USA.
authors.forename: S
authors.initials: S
authors.lastname: Chaudhary
authors.affiliation: Ames National Laboratory, Ames, IA 50011, USA. vaknin@ameslab.gov and Department of Physics and Astronomy, Iowa State University, Ames, IA 50011, USA.
authors.forename: D
authors.initials: D
authors.lastname: Vaknin
mesh_terms: D006845:Hydrocarbons, Fluorinated / Q000737:chemistry*; D011145:Polyvinyls / Q000737:chemistry*; D014961:X-Ray Diffraction; D005465:Fluorocarbon Polymers
chemical_list: D006845:Hydrocarbons, Fluorinated; D011145:Polyvinyls; C024865:polyvinylidene fluoride; D005465:Fluorocarbon Polymers; C074585:trifluoroethene