相关论文: Density Functional Theory and Molecular Dynamics S…

The development of polymer blends has emerged as a strategic approach for designing multifunctional materials with enhanced tailored characteristics. Current work investigates and reports for the first time, the structure-property…

Equilibrium polyethylene crystal structure, cohesive energy, and elastic constants are calculated by density-functional theory applied with a recently proposed density functional (vdW-DF) for general geometries [Phys. Rev. Lett. 92, 246401…

Piezoelectric fluoropolymers convert mechanical energy to electricity and are ideal for sustainably providing power to electronic devices. To convert mechanical energy, a net polarization must be induced in the fluoropolymer, which is…

Despite extensive research on piezoelectric polymers since the discovery of piezoelectric poly(vinylidene fluoride) (PVDF) in 1969, the fundamental physics of polymer piezoelectricity has remained elusive. Based on the classic principle of…

We report on the fabrication and electrical characterization of few-layer graphene (FLG) devices coated with a ferroelectric polymer layer of poly(vinylidene fluoride/trifluoroethylene) [P(VDF/TrFE)]. Highly stable and reliable resistance…

The dipoles in ferroelectric copolymer P(VDF-TrFE) can be driven by electric field, introducing phonon transport modulations through polarizing molecular chains. The thermal conductivity in single 75/25 P(VDF-TrFE) nanofibers is found to…

The structures and electronic states in all polymorphs of poly(vinylidene fluoride) (PVDF) were calculated in various levels using the CRYSTAL software. The calculated lattice constants with PBE0/cc-pVTZ agreed well with experimental…

Polyvinylidenefluoride (PVDF) a semicrystalline pieozoelectric polymer was synthesized with varying process conditions and its ferroelectric domain orientations were studied using piezoresponse force microscope (PFM). PVDF thin films…

This study presents the simulation, experimentation, and design considerations of a Poly(vinylidene fluoride co-trifluoroethylene)/ Polyethylene Terephthalate (PVDF-TrFe / PET), laser-cut, flexible piezoelectric energy harvester. It is…

We provide a detailed insight into piezoelectric energy generation from arrays of polymer nanofibers. For sake of comparison, we firstly measure individual poly(vinylidenefluoride-co-trifluoroethylene) (P(VDF-TrFe)) fibers at well-defined…

Polyvinylidene difluoride (PVDF) is a ferroelectric polymer characterized by negative strain along the direction of the applied electric field. However, the electromechanical response mechanism of PVDF remains unclear due to the complexity…

Two structures have been proposed in the literature for the b-phase of the ferroelectric polymer, poly(vinylidene fluoride) (b-PVDF); planar-zigzag and alternatively-deflected forms. Using density-functional theory, we have found the…

The development of kinetic energy functional (KEF) is known as one of the most difficult subjects in the electronic density functional theory (DFT). In particular, the sound description of chemical bonds using a KEF is a matter of great…

We investigate the electromechanical interactions in individual P(VDF-TrFE) nanowires in response to localized electrical poling via a conducting atomic force microscope tip. Spatially resolved measurements of piezoelectric coefficients and…

This research describes a piezoelectric Poly(vinylidene fluoride-co-trifluoroethylene)/ Polyethylene Terephthalate energy harvester for structural health monitoring of wind turbines. The piezoelectric energy harvester was made of a…

Halide perovskite-based photodiodes are promising for efficient detection across a broad spectral range. Perovskite absorber thin-films have a microcrystalline morphology, characterized by a high density of surface states and defects at…

Nano-graphene /polymer composites can functionas pressure induced electro-switches, at concentrations around their conductivity percolation threshold. Close to the critical point, the pressure dependence of the electron tunneling through…

The practical success of density functional theory (DFT) is largely credited to the Kohn-Sham approach, which enables the exact calculation of the non-interacting electron kinetic energy via an auxiliary noninteracting system. Yet, the…

In order to obtain a reasonably accurate and easily implemented approach to many-electron calculations, we will develop a new Density Functional Theory (DFT). Specifically, we derive an approximation to electron density, the first term of…

Theoretical studies of photochemical processes require a description of the energy surfaces of excited electronic states, especially near degeneracies, where transitions between states are most likely. Systems relevant to photochemical…