Kiralnost od akiralnih tekućih kristala

Kiralnost od akiralnih tekućih kristala
Datum početka projekta
01.06.2015.
Datum kraja projekta
31.05.2017.
Status
Završen
Kategorija projekta
Projekti Hrvatske zaklade za znanost
Ugovoreni iznos financiranja
476.000 HRK

Danas su, materijali sa svojstvima tekućih kristala najpoznatiji po svojoj iznimno uspješnoj primjeni u industriji zaslona, a ipak pokazuju mnoštvo specifičnih svojstava koje predstavljaju veliki potencijal kako za nova temeljna istraživanja tako i za inovativnu primjenu povrh one u izradi zaslona. Prijedlog projekta se odnosi na nova istraživanja u području tekućih kristala u kojima se proučava stvaranje helikalnih struktura od molekula koje nisu kiralne, a proizlazi iz prethodnih istraživanja koja su pokazala da fleksibilno povezane dimerne molekule mogu pokazivati ovakvo opće ponašanje. Projektom je predviđena kombinacija eksperimentalnhi, računalnih i spektroskopskih istraživanja koja bi trebala pružiti značajne informacije o strukturnim i elektroničkim čimbenicima koji utječu na nastanak i stabilnost helikalne samoorganizacije što proširuje mogućnost za kontroliranu proizvodnju novih materijala za različite primjene npr. generatori male snage, umjetni mišić, itd

 

pic2

Rezultati:

  • T. Ivšić, M. Vinković, U. Baumeister, A. Mikleušević, A. Lesac*, “Towards understanding the NTB phase: a combined experimental, computational and spectroscopic study“, RSC Adv. 6 (2016) 5000-5007.

 

RSC-TOC

Combined experimental, computational and spectroscopic studies support the hierarchical model for the NTB phase that involves formation of embryonic self-assembly of the propeller-shaped dimeric molecules with syn-parallel orientation in the isotropic melt.

  • T. Ivšić, U. Baumeister, I. Dokli, A. Mikleušević and A. Lesac, “The effect of the structural variations on the incidence of the NTB phase“, Workshop “Twist-Bend Nematics and Beyond”, 7-8 April 2016, Southampton, UK (oral contribution)
workshop-pic

Combined experimental and computational studies showed that the incidence of the NTB phase and its thermal stability are highly sensitive to variations in the molecular structure and suggest that within a given series of materials the incidence of the NTB phase is governed by the synergy of the particular geometrical factors and anisotropy of the electrostatic potential distribution of the mesogenic core.

  • T. Ivšić, U. Baumeister, I. Dokli, A. Mikleušević, A. Lesac*, “Sensitivity of the NTB Phase Formation to the Molecular Structure of Imino-linked Dimers“, Liquid Crystals 44 (2017) 93-105. (http://dx.doi.org/10.1080/02678292.2016.1225832)

Here we report on the synthesis and mesomorphic properties of a series of imino-linked dimeric molecules. In order to improve our understanding of the structure–NTB phase correlations we studied the impact of geometric and electronic factors arising from variant mesogenic units, different spacer lengths and from the ratio (n/m) between the lengths of terminal chains (n) and spacer (m). From the perspective of the molecular geometry, the results show that the stability of the NTB phase rises with increasing effective molecular bending and with the broadening of the mesogenic unit, in particular near the spacer and that the n/m ratio has a substantial role in conjunction with the specific mesogenic unit. A computational study of the electronic properties showed that a broadening of the mesogenic core in the vicinity of the spacer is associated with an increased anisotropy of the electrostatic potential distribution. Within a given series of materials our study suggests that the incidence of the NTB phase and its thermal stability are governed by the synergy of specific geometrical factors and the anisotropy of the electrostatic potential distribution of the mesogenic core.

Glavni istraživač / voditelj
Andreja Lesac

Andreja Lesac, dr.sc.

viši znanstveni suradnik

Ostali suradnici

dr.sc. Irena Dokli

dr.sc. Trpimir Ivšić

dr.sc. Anamarija Knežević

dr.sc. Darko Kontrec

Temperaturno-kontrolirana X-ray analiza u suradnji s dr.sc. Ute Baumeister (Martin Luther University Halle-Wittenberg, Njemačka)