Active nematic fluid films

Optically tunable chiral nematic mesoporous cellulose films.

Demand for sustainable functional materials has never been larger. The introduction of functionality into pure cellulose might be one step forward in this field as it is one of the most abundant natural biopolymers. In this paper, we demonstrate a straightforward and scalable way to produce iridescent, mesoporous cellulose membranes with tunable colors and porosity. Concomitant assembly of cell...

Effective interactions of colloids on nematic films.

The elastic and capillary interactions between a pair of colloidal particles trapped on top of a nematic film are studied theoretically for large separations d. The elastic interaction is repulsive and of quadrupolar type, varying as d⁻⁵. For macroscopically thick films, the capillary interaction is likewise repulsive and proportional to d⁻⁵ as a consequence of mechanical isolation of the syste...

Fluctuation-Induced Structural Forces in Nematic Films

Nematic films and radially anisotropic Delaunay surfaces.

We develop a theory of axisymmetric surfaces minimizing a combination of surface tension and nematic elastic energies which may be suitable for describing simple film and bubble shapes. As a function of the elastic constant and the applied tension on the bubbles, we find the analogues of the unduloid, sphere, and nodoid in addition to other new surfaces.

Critical Splay-Bend Deformation of Nematic Films

I n t h i n nemat ic f i lms the d i rec tor field n may on ly depend on z, the n o r m a l to the film p lane. There are two stable conf igurat ions w i t h less than a l l three types of de fo rma t ion present, the pure tw is t and the pure splay-bend. Fo r the pure tw is t under the add i t i ona l in f luence of an ex te rna l field n o r m a l to the tw is t p lane the range of s tab i l ...