TY - JOUR
T1 - Enhanced elasticity and soft glassy rheology of a smectic in a random porous environment
AU - Bandyopadhyay, Ranjini
AU - Liang, Dennis
AU - Colby, Ralph H.
AU - Harden, James L.
AU - Leheny, Robert L.
PY - 2005/3/18
Y1 - 2005/3/18
N2 - We report studies of the frequency-dependent shear modulus, G*(ω) = G′(ω) + iG″(ω), of the liquid crystal octylcyanobiphenyl (8CB) confined in a colloidal aerosil gel. With the onset of smectic order, G′ grows approximately linearly with decreasing temperature, reaching values that exceed by more than 3 orders of magnitude the values for pure 8CB. The modulus at low temperatures possesses a power-law component, G*(ω) ∼ ωα, with exponent α that approaches zero with increasing gel density. The amplitude of G′ and its variation with temperature and gel density indicate that the low temperature response is dominated by a dense population of defects in the smectic. In contrast, when, the 8CB is Isotropic or nematic, the modulus is controlled by the elastic behavior of the colloidal gel.
AB - We report studies of the frequency-dependent shear modulus, G*(ω) = G′(ω) + iG″(ω), of the liquid crystal octylcyanobiphenyl (8CB) confined in a colloidal aerosil gel. With the onset of smectic order, G′ grows approximately linearly with decreasing temperature, reaching values that exceed by more than 3 orders of magnitude the values for pure 8CB. The modulus at low temperatures possesses a power-law component, G*(ω) ∼ ωα, with exponent α that approaches zero with increasing gel density. The amplitude of G′ and its variation with temperature and gel density indicate that the low temperature response is dominated by a dense population of defects in the smectic. In contrast, when, the 8CB is Isotropic or nematic, the modulus is controlled by the elastic behavior of the colloidal gel.
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U2 - 10.1103/PhysRevLett.94.107801
DO - 10.1103/PhysRevLett.94.107801
M3 - Article
C2 - 15783523
AN - SCOPUS:18044365020
SN - 0031-9007
VL - 94
JO - Physical review letters
JF - Physical review letters
IS - 10
M1 - 107801
ER -