Enhanced Electromechanical Responses in Films Containing Charged Di-block Copolymers
ORAL
Abstract
Thin films of dibock copolymers with an ionic block covalently linked to a deuterated neutral block were studied using in situ specular neutron reflectivity in applied voltages of varying magnitudes. Effects of applied voltages (0.5, 2, 5, and 7 kV in vacuum) at room temperature and 120o C were studied. Analysis of the specular reflectometry data shows that electric field doesn’t affect the local structure at the room temperature. In contrast, local structural rearrangements were observed in the films at even 0.5 kV at 120o C, which corresponds to electric field < 1V /μm. Such an enhanced electromechanical response of the film is attributed to the presence of bromine counterions, in agreement with previous theoretical studies. Overall, this work confirms the significant role played by counterions in affecting electromechanical responses of ionic diblock copolymers.
*This work was supported by Center for Nanophase Materials Sciences (CNMS), which is a USDepartment of Energy, Office of Science User Facility at Oak Ridge National Laboratory. Aportion of this research used resources at the SNS, a Department of Energy (DOE) Office ofScience User Facility operated by ORNL. Neutron reflectometry measurements were carriedout on the Liquids Reflectometer at the SNS, which is sponsored by the Scientific UserFacilities Division, Office of Basic Energy Sciences, DOE. ORNL is managed by UT-BattelleLLC for DOE under Contract DE-AC05-00OR22725.
–
Presenters
-
Rajeev Kumar
- Oak Ridge National Laboratory