基于Android平台的工程图学助教助学系统研究与实现

Release time:2024-12-24 Hits:

Key Words:POLY(VINYLIDENE FLUORIDE); NANOCOMPOSITES; COMPOSITES; NANOPARTICLES; DENSITY; OXIDE

Abstract:With the development of modern electronic and electrical industry, it is still a great challenge to develop poly (vinylidene fluoride) (PVDF) based dielectric capacitors with high energy storage capability. Herein, a novel sandwich-like nanofiller was constructed via covalently grafting polyhedral oligomeric silsesquioxane onto graphene oxide nanosheets (GO@POSS), further PVDF/rGO@POSS film were fabricated via solvent-casting and in-situ thermal reduction processes. The results indicated that the grafting of POSS promoted the uniform dispersion of nanofillers to realize strong interfacial interaction with PVDF matrix. The optimal PVDF film containing 0.75 wt% rGO@POSS (0.75PGP-60) exhibited larger dielectric constant (epsilon r = 13.32) and higher breakdown strength (Eb = 339.1 MV m- 1), thus resulting in synchronous improvements on energy density (Ue = 5.42 J & sdot;cm- 3) and charge-discharge efficiency (eta = 73.1 %), which increased by 95.0 % and 19.4 % compared to pure PVDF, respectively. Meanwhile, it presented excellent cycling stability with 97.6 % energy density retention after 10000th cycles. The improved energy storage capability was attributed to reasonably-designed sandwichlike nanofiller: the formation of rGO micro-capacitors raised the dielectric constant of PVDF nanocomposites, while the insulative POSS layer helped to improve its breakdown strength and decrease its dielectric loss. The current work provides a novel and efficient paradigm to design PVDF nanocomposites with promising dielectric properties and energy storage capacity, and further contributes to broadening the practical applications of advanced dielectric capacitors.

Volume:259

Issue:

Translation or Not:no