What Is an Electret?
Polymer electrets are also called electret compounds. Polymer material with electret function. The polymer electret can be made into a flexible film, and at the same time, it has excellent charge storage capacity and has a promising future. There are two main types. One is a highly insulating material, such as polytetrafluoroethylene and a copolymer of fluoroethylene and propylene, which have a relatively good ability to maintain the injected charge. The other is a polarizable polymer, such as polyvinylidene fluoride. There is a permanent dipole moment in the molecule. After polarization, this material can maintain the directivity of its dipole in a certain temperature range. Often exhibits piezoelectric and thermoelectric properties. Both of these electrets have a wide range of practical uses.
- Polymer electrets are polymer dielectric materials that have a dipole orientation and have been polarized for a long time [1]
- Heating polymer to glass transition in a DC high voltage electric field
- Natural polymers such as Brazilian palm wax, polysaccharides, polysaccharides, hard rubber and synthetic polymer polycarbonate, polymethyl methacrylate, polypropylene, copolymers of tetrafluoroethylene and perfluoropropylene can be made Polar body.
- Polymer electret materials have been used in microphones, underwater acoustic detectors, powerless phones, electrometers, and air filters.
- The preparation methods include electron or ion implantation method, polarization method and stretch polarization molding method, etc. According to different uses, different preparation molding methods can be selected [1] .