On the effects of different trans and cis populations in azobenzene liquid crystal elastomers: a Monte Carlo investigation

Gregor Skačej (Avtor), Lara Querciagrossa (Avtor), Claudio Zannoni (Avtor)

Povzetek

We investigate main-chain liquid crystal elastomers (LCEs) formed by photoresponsive azobenzene units with different populations of trans and cis conformers (from fully trans to fully cis). We study their macroscopic properties as well as their molecular organization using extensive Monte Carlo simulations of a simple coarse-grained model where the trans and cis conformers are represented by soft-core biaxial Gay−Berne particles with size and interaction energy parameters obtained by fitting a bare bone azobenzene moiety represented at atomistic level. We find that increasing the fraction of cis conformers, as could be obtained by near-UV irradiation, shifts the nematic−isotropic transition to a lower temperature, consistently with experiment, while generating internal stress in a clamped sample. An analysis of pair distributions shows that the immediate surroundings of a bent cis molecule are slightly less dense and more orientationally disordered in comparison with that of a trans conformer. Comparing nematic and smectic LCEs, actuation in the smectic phase proved less effective, disrupting the smectic layers to some extent but preserving orientational order of the azobenzene moieties.

Ključne besede

tekočekristalni elastomeri;azobenzen;fizikalna kemija;liquid crystal elastomers;azobenzene;physical chemistry;

Podatki

Jezik:	Angleški jezik
Leto izida:	2023
Tipologija:	1.01 - Izvirni znanstveni članek
Organizacija:	UL FMF - Fakulteta za matematiko in fiziko
UDK:	544.25
COBISS:	160768771
ISSN:	2637-6105
Št. ogledov:	15
Št. prenosov:	4
Ocena:	0 (0 glasov)
Metapodatki:

Ostali podatki

Sekundarni jezik:	Slovenski jezik
Sekundarne ključne besede:	tekočekristalni elastomeri;azobenzen;fizikalna kemija;
Vrsta dela (COBISS):	Članek v reviji
Strani:	str. 5805−5815
Letnik:	ǂVol. ǂ5
Zvezek:	ǂiss. ǂ8
Čas izdaje:	2023
DOI:	10.1021/acsapm.3c00361
ID:	21439510