Suppressing depolarization by tail substitution in an organic supramolecular ferroelectric

Abstract

The depolarization problem of a supramolecular organic ferroelectric is solved by simple molecular structure modification and blending.

Negative piezoelectric effect in an organic supramolecular ferroelectric

“…As seen in Fig. 5a, the small-signal d 33 (black open symbols) slightly deteriorates from around À4.7 pm V À1 to À3.5 pm V À1 with disorder. In contrast, the large-signal d 33 has a strong growing trend from À5 pm V À1 to À21 pm V À1 .…”

“…Considering a single self-assembled molecular stack, one would expect a positive piezoelectric response at the nanoscale due to the applied field rotating the amide dipoles further out-of-plane, which does not agree with the measured macroscopic negative piezoelectric constants. To this end, we have simulated the behavior of a single molecular stack consisting of 18 methyl-tailed BTAs using the energy minimization principle in molecular dynamics 33 and found that with increasing field, Fig. 3 Simulated field-induced axial lattice strain.…”

“…31 Differently to the conventional liquidcrystalline materials used for electrooptical applications, BTA maintains its macrodipole orientation at zero external field due to p-p stacking and hydrogen-bonding, which allows it to keep the polarization for up to 10 years at room temperature. [31][32][33] The overall performance of thin-film BTA capacitor devices is comparable to devices based on P(VDF-TrFE), additionally offering some advantages like lower processing temperatures, easy chemical tuning and a wider operational temperature window. 31,34,35 In this study we present interferometrically measured converse piezoelectric response in solution-processed thin-film BTA capacitor devices.…”

Understanding the remarkable difference in liquid crystal behaviour between secondary and tertiary amides: the synthesis and characterisation of new benzanilide-based liquid crystal dimers

“…These systems tend to predominantly form smectic phases, again attributed to intermolecular hydrogen bonding between the amide groups. Indeed, the use of amide groups in structures such as benzene tricarboxamides (BTA) [19][20][21][22] , hydrazine derivatives [23][24][25][26][27][28] , or peptide residues [29][30][31] promotes columnar liquid crystal phases in which hydrogen bonding stabilises the columns.…”

Ferroelectrically Switchable Axial Polarization in Columnar Liquid Crystalline Phases

“…Based on the abovementioned studies, Kemerink's group further investigated some branched BTA analogs (Figure ). They expected that sterically hindered peripheral groups would reinforce the retention time.…”