Shear instabilities of freely standing thermotropic smectic-A films

In this Letter we discuss theoretically the instabilities of thermotropic freely standing smectic-A films under shear flow\cite{re:wu}. We show that, in Couette geometry, the centrifugal force pushes the liquid crystal toward the outer boundary and induces smectic layer dilation close to the outer boundary. Under strong shear, this effect induces a layer buckling instability. The critical shear rate is proportional to $1/\sqrt{d}$, where $d$ is the thickness of the film.Comment: 12 pages, 2 figure

Observations of the collapse of dilute lyotropic lamellar phases under sheer flow

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Observations of the collapse of dilute lyotropic lamellar phases under sheer flow

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Observations of the collapse of dilute lyotropic lamellar phases under sheer flow

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Molecular Structure and Melting: Implications for Phase Change Materials

Phase change materials (PCM) offer a promising technology for thermal energy storage, load leveling, and peak shifting applications. A desirable PCM has a melting temperature within the temperature boundaries of its application, and a high change in enthalpy on melting. Knowledge of the relationships between these thermodynamic properties and molecular structure would advance informed selection of PCM candidates for a given application. In the present investigation, the relationship between structure (length of alkyl chains) and properties has been investigated for isomeric esters, showing that esters containing longer individual alkyl chains have higher melting temperatures, and higher enthalpy changes on melting. The melting entropy changes, however, are relatively independent of the alkyl chain distribution.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Observation of a finite-time singularity in needle propagation in Hele-Shaw cells

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Dynamic light scattering from lyotropic lamellar phases subjected to a flow field

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Dynamic light scattering from lyotropic lamellar phases subjected to a flow field

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