\”ACS Materials Letter\” high dielectric properties of the flexible transparent polymeric material
Recently, University of California, Los Angeles (UCLA) Professor He Xi Min team with Professor Cai Xu Fu College ofand Engineering, Sichuan University team , in collaboration \”ACS Materials Letter\” [123 ] online published a study \”MolecularFerroelectric-modified Polyvinyl Alcohol Flexible and TransparentHigh-dielectric-constant Polymers films Based on\” entitled. The study, has capability of spontaneous polarization of ferroelectric material of small molecules and the polyvinyl alcohol film-forming material in situ crystallization obtained with the embodiment transparent high dielectric constant flexible polymeric film . Polymeric material is a flexible electrical development needs memory device of a high energy density, has excellent mechanical properties and processing properties of the multi-substrate composite is preferably. However, the dielectric constant of the polymeric material is generally small, a lot of work in order to improve the dielectric constant of the polymer are now published by addition of having a high dielectric constant of ferroelectric ceramics, or a semiconductor having conductivity, a metal material, and a carbon nanomaterial. Wherein the ferroelectric ceramics because of its spontaneous polarization electrons have a higher dielectric constant in the electric field, such as barium titanate (BTO), and lead zirconate titanate (PZT). However, these ferroelectric ceramics have their own deficiencies, such as high density, heavy pollution, high energy consumption, easy production, and other issues too rigid. At the same time, the dielectric material with improved ferroelectric ceramics generally require a relatively high amount of addition, which also lead to stress concentration, increased defects, thereby reducing the polymer composite transparency and flexibility. We hope added in situ may be dissolved in water and an organic solvent having a high Curie point temperature, a spontaneous polarization of molecules of ferroelectric crystal material dipoles, while increasing energy density and dielectric constant of the polymer substrate holding material also transparency and flexibility. Further in order to meet the performance and environmental requirements molecular dispersion of ferroelectric crystal, chosen herein as the polymer base material has a water solubility and good film forming property of the polyvinyl alcohol. Both added to give a small amount of low molecular ferroelectric crystals uniformly dispersed in the composite system by way of forming the solution, the material having a high systemPermittivity while also maintaining excellent mechanical and optical properties. low addition (4.1-9wt.%) TEDA.C energy density and dielectric constant of the composite system of polyvinyl alcohol 10 to 100 times to achieve pure system, the remnant polarization increases 3200-fold, to maintain transparency more than 85%, the storage modulus increased by 116%, the elongation at break up to 274% . Herein ferroelectric binding small molecules with the polymer material provides a salt research ideas, has the potential to be applied to next-generation multifunction flexible energy storage device.
\”ACS Materials Letter\” (DOI: 10.1021 / acsmaterialslett.0c00086). The first author of the paper for the Sichuan University College of Polymer Science and Engineering doctoral Yangyun Yun and materials science at UCLA andEngineering doctoral student Zhao Yusen , corresponding author for the College of Polymer Science and Engineering Professor Cai Xu Fu and materials science and engineering professor at the University of California, Los Angeles He Xi Min, Sichuan University, . Team Profile: UCLA team HE Xi Min is committed to the development of bionic versatile and flexible polymer gel materials, and promote its application in the fields of environment, energy, robotics, etc.