Effect of Aspect Ratio on Liquid Crystal Behavior of Ellipsoidal Particles†

doi:10.7503/cjcu20190059

Abstract

Abstract:

The Gay-Berne model and molecular dynamics simulation method was used to study the influences of aspect ratio on the liquid crystal behaviors of ellipsoidal particles, especially focusing on nematic and smectic phases. The results indicated that the ellipsoids with a relatively small aspect ratio favor the formation of nematic phases, while the ellipsoids with a relatively large aspect ratio prefer the formation of smectic phases. Furthermore, the formation processes of the nematic and smectic phases in detail were analyzed. The results provide theoretical guidance for designing different types of liquid crystals and understanding the formation mechanism of liquid crystal.

Key words: Ellipsoidal particle, Aspect ratio, Nematic phase, Smectic phase, Gay-Berne model, Molecular dynamics

CLC Number:

O641
O631

TrendMD:

XU Mingjie,SUN Yuwei,ZHU Youliang,FU Cuiliu,HUANG Yineng,LI Zhanwei,SUN Zhaoyan. Effect of Aspect Ratio on Liquid Crystal Behavior of Ellipsoidal Particles^†[J]. Chem. J. Chinese Universities, 2019, 40(6): 1201.

Figures/Tables 6

Fig.1 Interaction potential(U) of uniaxial ellipsoids with different aspect ratio as a function of separation rij for side-by-side and end-to-end configurations

Fig.2 Snapshots at different temperatures of T=2.8(A) and T=2.0(B), radial distribution function gr(C) and parallel radial distribution function g‖r‖(D)

Fig.3 Characterization methods of order parameters <P2>(A), radial distribution function g(r)(B) and parallel radial distribution function g‖(r‖)(C)

Fig.4 Snapshots for different aspect ratios at T=2.8 c/a: (A) 2∶1; (B) 3∶1; (C) 4∶1; (D) 5∶1.

Fig.5 Different characterization methods of order parameters <P2>(A), radial distribution function gr(B) and parallel radial distribution function g‖r‖(C)

Fig.6 Formation processes of the nematic phase in Fig.2(A)(A—D) and the smectic phase in Fig.2(B)(E—H) (A, E) 5.0×105 τ; (B, G) 7.0×105 τ; (C) 8.5×105 τ; (D) 1.0×106 τ; (F) 6.0×105 τ; (H) 9.0×105 τ.

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