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Journal of Physical Chemistry B
Volumn 113, Issue 12, 2009, Pages 3853-3872
Phase diagrams of semisoft nematic elastomers
Author keywords

[No Author keywords available]
Indexed keywords

ELASTOMERS; MAGNETIC FIELDS; PHASE DIAGRAMS; RUBBER; STRESS-STRAIN CURVES;
EID: 65249167071     PISSN: 15206106     EISSN: None     Source Type: Journal    
DOI: 10.1021/jp8082002     Document Type: Article
Times cited : (15)
References (42)
  • 4
    • 84906400728 scopus 로고    scopus 로고
    • de Gennes, P. Weak Nematic Gels. In Liquid Crystals of One- and Two-Dimensional Order and Their Applications; Helfrich, W., Heppke, G., Eds.; Springer-Verlag: Garmishc-Partenkirchenm, Germany, 1980; pp 231- 237.
    • de Gennes, P. Weak Nematic Gels. In Liquid Crystals of One- and Two-Dimensional Order and Their Applications; Helfrich, W., Heppke, G., Eds.; Springer-Verlag: Garmishc-Partenkirchenm, Germany, 1980; pp 231- 237.
  • 5
    • 0004254996 scopus 로고
    • Ciferi, A, Krigbaum, W, Meyer, R. B, Eds, Academic Press: New York
    • Polymer Liquid Crystals; Ciferi, A., Krigbaum, W., Meyer, R. B., Eds.; Academic Press: New York, 1982.
    • (1982) Polymer Liquid Crystals
  • 33
    • 84906357591 scopus 로고    scopus 로고
    • The free energy density of an elastomer can always be written as f =f el(u, fQ (Q̃, f c(u, Q̃, Here Q is the tensor constructed to transform, like u, as a tensor under rotations in the reference space [see ref 34 for details, Thus uijQ̃Qij is a scalar, whereas u ¡jQ¡j is not because Q ¡j transforms as a tensor under rotations in the target and not the reference space. The conversion between Q and Q is implemented with the aid of the polar decomposition theorem: Λ, OΛs, where Λs, ΛTΛ)1/2, δ, 2u)1/2 is the symmetric deformation tensor, and O, ΛΛs -1/2 is an orthogonal rotation matrix whose left index transforms in the target space and whose right index transforms in the references space. Th
    • eff[u] =-T ln ∫D̃Q̃ exp(-F[u, Q]/T ) depends only on u. This energy can be expressed in terms of a Landau expansion in u. A theory in terms of the symmetric-traceless part of u only can then be obtained by integrating out Tru. The integration over Q gives rise to a shear modulus μ that passes through zero if there is an isotropic-to-nematic transition in /ρ(Q) [see ref 35]. A theory, like the neoclassical theory, expressed in terms of Λ and Q can be converted into one in terms of u and Q using the polar decomposition results above.
  • 39
    • 84906372076 scopus 로고    scopus 로고
    • Tricritical points are characterized by three fields: the temperature, the ordering field that aligns the order parameter, and the non-ordering field that couples not to the order parameter but to another field that can make the ordered phase disappear. The classical tricritical point occurs in He- He3 mixtures. The order parameter is the superfluid condensate wavefunction ψ, and the ordering field is the field h conjugate to it. Increasing He3 concentration tends to destroy superfluid order, and the non-ordering field is the He3 chemical potential, μ 3. The T -h -μ 3 phase diagram in the vicinity of the tricritical point has the same geometry as that shown in Figure 4 near the tricritical point tZ, The order parameter of the semi-soft phase SZ is η, Decreases in the uniaxial order parameter S destroy the semi-soft phase near and below tZ just as increases in the He3 concentration destroy the superflu
    • Tricritical points are characterized by three fields: the temperature, the ordering field that aligns the order parameter, and the non-ordering field that couples not to the order parameter but to another field that can make the ordered phase disappear. The classical tricritical point occurs in He- He3 mixtures. The order parameter is the superfluid condensate wavefunction ψ, and the ordering field is the field h conjugate to it. Increasing He3 concentration tends to destroy superfluid order, and the non-ordering field is the He3 chemical potential, μ 3. The T -h -μ 3 phase diagram in the vicinity of the tricritical point has the same geometry as that shown in Figure 4 near the tricritical point tZ . The order parameter of the semi-soft phase SZ is η . Decreases in the uniaxial order parameter S destroy the semi-soft phase near and below tZ just as increases in the He3 concentration destroy the superfluid phase. Since σxxuxx + huzz ) σxxη 1 + (2h - " σxx )S /3, the ordering field, which induces η 1 ) ηx, is σxx, and the nonordering field, which induces changes in S, is (2h - " σxx )/3.
  • 42
    • 65249134180 scopus 로고    scopus 로고
    • Unpublished work
    • Lubensky, T. C.; Ye, F. Unpublished work, 2008.
    • (2008)
    • Lubensky, T.C.1    Ye, F.2

* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.