Affiliation:
1. Institut des Matériaux et Institut des Sciences et Ingénierie Chimiques Laboratoire des Polymères École Polytechnique Fédérale de Lausanne (EPFL) Bâtiment MXD, Station 12 Lausanne CH‐1015 Switzerland
2. Group for Ferroelectrics and Functional Oxides Institute of Materials École Polytechnique Fédérale de Lausanne (EPFL) Lausanne CH‐1015 Switzerland
3. Department of Chemistry University of Tennessee Knoxville TN 37996 USA
Abstract
AbstractPiezo‐ and pyroelectric materials are of interest, for example, for energy harvesting applications, for the development of tactile sensors, as well as neuromorphic computing. This study reports the observation of pyro‐ and piezoelectricity in thin surface‐attached polymer brushes containing zwitterionic and electrolytic side groups that are prepared via surface‐initiated polymerization. The pyro‐ and piezoelectric properties of the surface‐grafted polyelectrolyte brushes are found to sensitively depend on and can be tuned by variation of the counterion. The observed piezo‐ and pyroelectric properties reflect the structural complexity of polymer brushes, and are attributed to a complex interplay of the non‐uniform segment density within these films, together with a non‐uniform distribution of counterions and specific ion effects. The fabrication of thin pyroelectric films by surface‐initiated polymerization is an important addition to the existing strategies toward such materials. Surface‐initiated polymerization, in particular, allows for facile grafting of polar thin polymer films from a wide range of substrates via a straightforward two‐step protocol that obviates the need for multistep laborious synthetic procedures or thin film deposition protocols. The ability to produce polymer brushes with piezo‐ and pyroelectric properties opens up new avenues of application of these materials, for example, in energy harvesting or biosensing.
Funder
China Scholarship Council
National Science Foundation
Subject
Mechanical Engineering,Mechanics of Materials,General Materials Science