Multi-functional electroactive tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride (THV)/magnesium diboride (MgB2) composite reactive material
Abstract
Fluoropolymers have weak electroactive properties but are often paired with other materials (inclusions) to form a composite with enhanced electroactive properties and when those inclusions are a metal or metalloid fuel (e.g., Al, Si, B) they can then function as electroactive reactive materials. There is strong interest in understanding the electromechanical (piezo, flexo, dielectric) properties toward the development of multifunctional energetics. Specifically, in this effort, we report the influence of magnesium diboride (MgB2) on the electroactive and combustion properties in a composite system with the fluoropolymer tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride (THV). The dielectric, flexoelectric, piezoelectric, burning rate, and heat of reaction are investigated for composites with 50–70 wt. % MgB2 loading. It is observed that with an increase in solids loading that the dielectric, flexoelectric, and burning rate increase. For example, at 70 wt. % MgB2, the measured dielectric constant was 298 ± 10, and the flexoelectric coefficient was 16.6 ± 1.2 nC/m. Unexpectedly, a true piezoelectric coefficient (d33) was measured between 11.4 ± 0.2 and 13.0 ± 0.3 pC/N at these solids loadings. Due to the mechanical properties of these composite systems, an apparent piezoelectric coefficient of 108 pC/N was calculated indicating that these reactive materials are highly electroactive. The multifunctional properties are demonstrated by applying the force of the human body (via jumping) to a THV/MgB2 (50 wt. %) film. A peak voltage of 0.75 V was observed. This work indicates that a variety of reactive materials may offer multifunctional capabilities.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Feb 22, 2023
- Source ID
- 10.1063/5.0135023
Entities
People
- Lori J. Groven
- Mikel J. Zaitzeff
Organizations
- Air Force Office of Scientific Research
- South Dakota School of Mines and Technology