Extraordinarily High Dielectric Breakdown Strength of Multilayer Polyelectrolyte Thin Films

Abstract

The increased use of high-voltage electronics requires higher performance dielectric materials. These electrically insulating layers need as high of a dielectric breakdown strength as possible. Herein, multiple polyelectrolyte layer-by-layer assemblies were studied as high-voltage insulators. The influences of molecular weight, polymer backbone architecture, and thermal cross-linking were investigated. It was found that increasing the molecular weight of either the polycation or polyanion increases the breakdown strength due to removal of chain ends that can act as breakdown initiating sites. It was also found that a linear polymer backbone architecture leads to higher breakdown strength when compared to branched polymer architectures. Lastly, through thermal cross-linking, the breakdown strength is increased, and the previously mentioned molecular weight and architecture effects are diminished. These 200–400 nm thick polymer multilayer films exhibit breakdown strengths of ∼300–400 kV/mm. Their simple water-based processing makes them an interesting new option for protecting various types of electronics.

High Dielectric Breakdown Strength Nanoplatelet‐Based Multilayer Thin Films

“…Thermogravimetric analysis (TGA) was performed under air with a ramp of 10 °C min −1 using a A50 Thermogravimetric Analyzer (TA Instruments, New Castle, DE). Dielectric measurements were collected according to a previously published procedure, [ 24 ] with a voltage ramp rate of 0.01–0.05 kV s −1 and a 1 mA readout signaling the breakdown of the film. Breakdown strength was measured in ambient conditions using an SCI 290 Series Hipot Tester (Lake, Forest, IL) as a DC voltage source coupled with a spring‐loaded PolyK test fixture (Philipsburg, PA) to ensure constant electrode‐surface contact (≈0.52 mm 2 ).…”

“…This coating method has been shown to impart flame retardancy, [16,17] corrosion protection, [18,19] heat shielding, [20,21] gas barrier, [22,23] and more recently, and high dielectric breakdown strength. [24] When nanoplatelets are integrated into an LbL coating, typically as the anionic species, it resembles a nanobrick wall of platelets held together with a thin polymer mortar. [25][26][27] This microstructure is particularly beneficial for dielectric breakdown strength because it creates a tortuous path for charge transport, which inhibits the breakdown of the material.…”

Sustainable Additive Manufacturing of Polyelectrolyte Photopolymer Complexes

“…Polyelectrolyte-based materials, commonly comprised of a composite formed by a pairing of two oppositely charged polymers, possess a virtually limitless range of properties that make them useful in fire protection, [1,2] food packaging, [3,4] drug delivery, [5,6] antifouling, [7] insulation, [8] and more. They are very popular materials because they can be processed in an aqueous solvent, are often environmentally benign, and sometimes are bio-based and/ or biodegradable.…”

Flexible cyanoethyl cellulose-based nanocomposites with superior energy storage capability

“…9,[18][19][20][21][22] Conventional dielectric energy storage materials include bulk ceramics, inorganic thin films, polymers, and polymerbased nanocomposites. [22][23][24][25][26][27][28] Among these, the polymer-based nanocomposites with easier processing, good mechanical flexibility, and higher breakdown strength make them a promising candidate material for electrostatic capacitor applications. However, the dielectric constant (K) of polymer-based composite films is improved via incorporating different dimensional high-K inorganic fillers.…”