Revealing the antipolar order in the antiferroelectric SmZ phase by means of circular alignment.

Many ferroelectric nematic liquid crystals, like one of the archetype materials, DIO, do not have a direct paraelectric N to ferroelectric N phase transition, but exhibit yet another phase between N and N. This phase has recently been proposed to be antiferroelectric, with a layered structure of alternating polarization normal to the average director and is sometimes referred to as Smectic Z (SmZ). We have examined the SmZ phase in circularly rubbed (CR) cells, known to discriminate between the polar N and the non-polar N phase from the configuration of disclination lines formed.

New examples of ferroelectric nematic materials showing evidence for the antiferroelectric smectic-Z phase.

We present a new ferroelectric nematic material, 4-((4'-((trans)-5-ethyloxan-2-yl)-2',3,5,6'-tetrafluoro-[1,1'-biphenyl]-4-yl)difluoromethoxy)-2,6-difluorobenzonitrile (AUUQU-2-N) and its higher homologues, the molecular structures of which include fluorinated building blocks, an oxane ring, and a terminal cyano group, all contributing to a large molecular dipole moment of about 12.5 D. We observed that AUUQU-2-N has three distinct liquid crystal phases, two of which were found to be polar phases with a spontaneous electric polarization P of up to 6 µC cm.

Mesogenic Groups Control the Emitter Orientation in Multi-Resonance TADF Emitter Films.

The use of thermally activated delayed fluorescence (TADF) emitters and emitters that show preferential horizontal orientation of their transition dipole moment (TDM) are two emerging strategies to enhance the efficiency of OLEDs. We present the first example of a liquid crystalline multi-resonance TADF (MR-TADF) emitter, DiKTa-LC. The compound possesses a nematic liquid crystalline phase between 80 °C and 110 °C.

Observation of a uniaxial ferroelectric smectic A phase.

We report the observation of the smectic A, a liquid crystal phase of the ferroelectric nematic realm. The smectic A is a phase of small polar, rod-shaped molecules that form two-dimensional fluid layers spaced by approximately the mean molecular length. The phase is uniaxial, with the molecular director, the local average long-axis orientation, normal to the layer planes, and ferroelectric, with a spontaneous electric polarization parallel to the director.

Delayed preconditioning via Angiotensin-converting enzyme inhibition: pros and cons from an experimental study.

1. Bradykinin B(2) receptor activation confers preconditioning from ischaemic injury. In the present study, we tested whether an angiotensin-converting enzyme (ACE) inhibitor (captopril) could mediate delayed preconditioning and, thus, cardioprotection.