Development of polar nematic fluids with giant-\k{appa} dielectric properties

TL;DR

This paper reports the design and synthesis of polar nematic fluids with giant dielectric permittivity ({} > 10^4), achieved through molecular design supported by machine learning, leading to novel high-permittivity fluid materials and polar polymers.

Contribution

The study introduces a rational molecular design strategy, supported by machine learning, to create super-high- fluid materials with spontaneous polar ordering, expanding high- materials into fluid and polymer states.

Findings

Achieved dielectric permittivity greater than 10^4 in fluid materials.

Confirmed macroscopic spontaneous polar ordering in synthesized fluids.

Extended the design strategy to polar polymer materials.

Abstract

Super-high-\k{appa} materials that exhibit exceptionally high dielectric permittivity are recognized as potential candidates for a wide range of next-generation photonic and electronic devices. Generally, the high dielectricity for achieving a high-\k{appa} state requires a low symmetry of materials so that most of the discovered high-\k{appa} materials are symmetry-broken crystals. There are scarce reports on fluidic high-\k{appa} dielectrics. Here we demonstrate a rational molecular design, supported by machine-learning analyses, that introduces high polarity to asymmetric molecules, successfully realizing super-high-\k{appa} fluid materials (dielectric permittivity, {\epsilon} > 104) and strong second harmonic generation with macroscopic spontaneous polar ordering. The polar structures are confirmed to be identical for all the synthesized materials. Our experiments and computational calculation reveal the unique orientational structures coupled with the emerging polarity. Furthermore, adopting this strategy to high-molecular-weight systems additionally extends the novel material category from monomer to polar polymer materials, creating polar soft matters with spontaneous symmetry breaking.