Lamellar phase under shear : SANS measurements
نویسندگان
چکیده
منابع مشابه
Oscillating viscosity in a lyotropic lamellar phase under shear flow.
We report some time-dependent behavior of lyotropic lamellar phase under shear flow. At fixed stress, near a layering instability, the system presents an oscillating shear rate. We build up a new stress versus shear rate diagram that includes temporal behavior. This diagram is made of two distinct branches of stationary states which correspond, respectively, to disordered and ordered multilamel...
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A mesoscopic model of a diblock copolymer is used to study the stability of a uniform lamellar phase under a reciprocating shear flow. Approximate viscosity contrast between the microphases is allowed through a linear dependence of the (Newtonian) shear viscosity on monomer composition. We first show that viscosity contrast does not affect the composition of the base lamellar phase in an unboun...
متن کاملAnisotropic Small Angle Light and Neutron Scattering from a Lyotropic Lamellar Phase under Shear
The influence of shear on the lamellar phase of a semi-dilute solution (36il (w /w) of tetra ethylenglycol dodecylether (CH3[CH2]11 [OCH2CH2]40H, C12E4) in water was investigated by Small Angle Light Scattering (SALS), Small Angle Neutron Scattering (SANS) and rheology. A plateau modulus was determined by low amplitude oscillatory shear experiments. A strong scattering peak perpendicular to the...
متن کاملDiscotic Micellar Nematic and Lamellar Phases Under Shear-Flow
Small-angle neutron scattering was employed to study the effect of shear flow on the nematic (N) and lamellar (La) phases in aqueous solutions of cesium perfluoro-octanoate. Shear rates as high as 4000 s-l were used. The N phase was found to align with the director in the direction of the gradient velocity. The L, phase oriented with lamellae parallel to the shear plane. This change in equilibr...
متن کاملShear-induced collapse in a lyotropic lamellar phase.
An entropically stabilized cetylpyridinium chloride, hexanol, and heavy brine lyotropic lamellar phase subjected to shear flow has been observed here by small angle neutron scattering to undergo collapse of smectic order above a threshold shear rate. The results are compared with theories predicting that such a lamellar phase sheared above a critical rate should lose its stability by a loss of ...
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ژورنال
عنوان ژورنال: Le Journal de Physique IV
سال: 1993
ISSN: 1155-4339
DOI: 10.1051/jp4:1993839