We prepare solid-stabilized emulsions using paramagnetic particles at an oil/water interface that can undergo macroscopic phase separation upon application of an external magnetic field. A critical field strength is found for which emulsion droplets begin to translate into the continuous-phase fluid. At higher fields, the emulsions destabilize, leading to a fully phase-separated system. This effect is reversible, and long-term stability can be recovered by remixing the components with mechanical agitation.

Aqueous suspension droplets of monodisperse latex or latex and gold nanoparticles mixtures assume spherical shape on superhydrophobic substrates. The drying sessile droplets serve as macroscopic templates for assembling microspheres into closed‐packed structures. Upon illumination, the supraparticles display discrete colored rings because of the periodic arrangement of latex particles in the surface layer. The physical origin of the colored patterns is explained in detail.

The growth of a cultivated typical brain tumor is studied in this work. The tumor is analyzed both dynamically and morphologically. We have measured its fractal dimension to be d f 1.21 6 0.05. From its dynamical behavior we determine the scaling critical exponents of this circular symmetry system which are compatible with the linear molecular beam epitaxy universality class. A very important feature of tumor profiles is that they are super-rough, which constitutes the first (1 1 1)-dimensional experiment in literature with super-roughness. The results obtained from the dynamics study make manifest two very surprising features of tumor growth: Its dynamics is mainly due to contour cells and the tendency of an interface cell to duplicate is a function of the local curvature.[ S0031-9007(98)

We study shape and buckling transitions of particle-laden sessile and pendant droplets that are forced to shrink in size. Monodisperse polystyrene particles were placed at the interface between water and decane at conditions that are known to produce hexagonal, crystalline arrangements on flat interfaces. As the volumes of the drops are reduced, the surface areas are likewise diminished. This effectively compresses the particle monolayer coating and induces a transition from a fluid film to a solid film. Since the particles are firmly attached to the interface by capillary forces, the shape transitions are reversible and shape/volume curves are the same for drainage and inflation. Measurements of the internal pressure of the drops reveal a strong transition in this variable as the buckling transition is approached.