Hong-en LIU, Jin-bing WU, Meng-fei LIU, et al. Stability of split-core configuration confined in nematic liquid crystal droplets under submicron scale[J]. Chinese journal of liquid crystals and displays, 2021, 36(3): 343-354.
DOI:
Hong-en LIU, Jin-bing WU, Meng-fei LIU, et al. Stability of split-core configuration confined in nematic liquid crystal droplets under submicron scale[J]. Chinese journal of liquid crystals and displays, 2021, 36(3): 343-354. DOI: 10.37188/CJLCD.2020-0246.
Stability of split-core configuration confined in nematic liquid crystal droplets under submicron scale
the stability of split-core configuration confined in nematic liquid crystal droplets with submicron scale under homeotropic anchoring boundary condition is investigated. Results show that there are radial and ring structures under the strong anchoring boundary condition and single constant approximation. According to the difference of the radius
the two structures will become stable respectively
i.e.
the ring structure is stable when the radius is larger
and the radial structure is stable when the radius is smaller. Under the condition of elastic anisotropy
a stable ring structure and a metastable split-core structure will appear. Furthermore
the results show that if the effect of
k
24
on the internal structure of the droplet is considered
when the boundary anchoring condition is changed from strong anchoring to weak anchoring (take anchoring strength
w
=10
-4
J/m
2
as an example) and under the single constant approximation
it is found that there would be three structures
i.e.
radial structure
ring structure and uniform state structure
and the radial structure is stable state
in addition
the stability among structures is not affected by the effect of
k
24
; under the condition of elastic anisotropy
the radial structure is transformed into the split-core structure. And it is still metastable when the effect of
k
24
is not considered; if the effect of
k
24
is considered
the split-core structure can be stable when the size and elastic anisotropy are within a certain range. In our simulation
it is found that the effect of
k
24
can make the split-core structure become stable for the first time.
关键词
Keywords
references
DAN A, AERY S, ZHANG S N, et al . Protein microgel-stabilized Pickering liquid crystal emulsions undergo analyte-triggered configurational transition[J]. Langmuir , 2020, 36(34): 10091-10102.
ORTIZ B J, BOURSIER M E, BARRETT K L, et al . Liquid crystal emulsions that intercept and report on bacterial quorum sensing[J]. ACS Applied Materials & Interfaces , 2020, 12(26): 29056-29065.
COATES D. Polymer-dispersed liquid crystals[J]. Journal of Materials Chemistry , 1995, 5(12): 2063-2067.
LAVRENTOVICH O D. Topological defects in dispersed words and worlds around liquid crystals, or liquid crystal drops[J]. Liquid Crystals , 1998, 24(1): 117-126.
KLEMAN M, LAVRENTOVICH O D. Soft Matter Physics : An Introduction [M]. Berlin: Springer, 2003: 20-35.
KRALJ S, VIRGA E G. Universal fine structure of nematic hedgehogs[J]. Journal of Physics A: Mathematical and General , 2001, 34(4): 829-838.
GARTLAND JR E C, MKADDEM S. Instability of radial hedgehog configurations in nematic liquid crystals under Landau-de Gennes free-energy models[J]. Physical Review E, 1999, 59(1): 563-567.
AN D, WANG W, ZHANG P W. On equilibrium configurations of nematic liquid crystals droplet with anisotropic elastic energy[J]. Research in the Mathematical Sciences , 2017, 4(1): 7.
TOMAR V, HERNÁNDEZ S I, ABBOTT N L, et al . Morphological transitions in liquid crystal nanodroplets[J]. Soft Matter , 2012, 8(33): 8679-8689.
SONG P, GAO Y Z, WANG F F, et al . Studies on the electro-optical and the light-scattering properties of PDLC films with the size gradient of the LC droplets[J]. Liquid Crystals , 2015, 42(3): 390-396.
GENG Y, JANG J H, NOH K G, et al . Through the spherical looking-glass: asymmetry enables multicolored internal reflection in cholesteric liquid crystal shells[J]. Advanced Optical Materials , 2018, 6(1): 1700923.
SCHOPOHL N, SLUCKIN T J. Hedgehog structure in nematic and magnetic systems[J]. Journal de Physique , 1988, 49(7): 1097-1101.
PENZENSTADLER E, TREBIN H R. Fine structure of point defects and soliton decay in nematic liquid crystals[J]. Journal de Physique , 1989, 50(9): 1027-1040.
SONNET A, KILIAN A, HESS S. Alignment tensor versus director: description of defects in nematic liquid crystals[J]. Physical Review E, 1995, 52(1): 718-722.
GUPTA J K, SIVAKUMAR S, CARUSO F, et al . Size-dependent ordering of liquid crystals observed in polymeric capsules with micrometer and smaller diameters[J]. Angewandte Chemie International Edition , 2009, 48(9): 1652-1655.
SIVAKUMAR S, GUPTA J K, ABBOTT N L, et al . Monodisperse emulsions through templating polyelectrolyte multilayer capsules[J]. Chemistry of Materials , 2008, 20(6): 2063-2065.
BACCHIOCCHI C, MIGLIOLI I, ARCIONI A, et al . Order and dynamics inside H-PDLC nanodroplets: an ESR spin probe study[J]. Journal of Physical Chemistry B, 2009, 113(16): 5391-5402.
PRISHCHEPA O O, SHABANOV A V, ZYRYANOV V Y. Director configurations in nematic droplets with inhomogeneous boundary conditions[J]. Physical Review E, 2005, 72(3): 031712.
DAVIDSON Z S, KANG L, JEONG J, et al . Chiral structures and defects of lyotropic chromonic liquid crystals induced by saddle-splay elasticity[J]. Physical Review E, 2015, 91(5): 050501(R).
ŽUMER S, KRALJ S. Influence of K 24 on the structure of nematic liquid crystal droplets[J]. Liquid Crystals , 1992, 12(4): 613-624.
MKADDEM S, GARTLAND JR E C. Fine structure of defects in radial nematic droplets[J]. Physical Review E , 2000, 62(5): 6694-6705.
GARTLAND JR E C. Scalings and limits of landau-de gennes models for liquid crystals: a comment on some recent analytical papers[J]. Mathematical Modelling and Analysis , 2017, 23(3): 414-432.
ZHOU X, ZHANG Z D, ZHANG Q, et al . Order reconstruction in a nanoconfined nematic liquid crystal between two coaxial cylinders[J]. Materials , 2015, 8(12): 8072-8086.
ERICKSEN J L. Inequalities in liquid crystal theory[J]. Physics of Fluids , 1966, 9(6): 1205-1207.
BERIS A N, EDWARDS B J. Thermodynamics of Flowing Systems: With Internal Microstructure [M]. Oxford: Oxford University Press, 1994.
KRALJ S, ROSSO R, VIRGA E G. Finite-size effects on order reconstruction around nematic defects[J]. Physical Review E, 2010, 81(2): 021702.