Engineering single-polymer micelle shape using nonuniform spontaneous surface curvature.

Conventional micelles, composed of simple amphiphiles, exhibit only a few standard morphologies, each characterized by its mean surface curvature set by the amphiphiles. Here we demonstrate a rational design scheme to construct micelles of more general shape from polymeric amphiphiles. We replace the many amphiphiles of a conventional micelle by a single flexible, linear, block copolymer chain containing two incompatible species arranged in multiple alternating segments.

Criterion for noise-induced synchronization: Application to colloidal alignment.

Colloidal bodies of irregular shape rotate as they descend under gravity in solution. This rotational response provides a means of bringing a dispersion of identical bodies into a synchronized rotation with the same orientation using programed forcing. We use the notion of statistical entropy to derive bounds on the rate of synchronization.

Orientational ordering of colloidal dispersions by application of time-dependent external forces.

We discuss a method of organizing incoherent motion of a colloidal suspension to produce synchronized, coherent motion, extending the discussion of our recent Letter [Moths and Witten, Phys. Rev. Lett.

Full alignment of colloidal objects by programed forcing.

By analysis and simulation, we demonstrate two methods for achieving complete orientational alignment of a set of identical asymmetric colloidal objects dispersed randomly in a fluid. Sedimentation or electrophoresis in a constant field can lead to partial alignment, in which the objects rotate about a common body axis, but the phases of rotation for these objects are random. We show that this phase disorder can be removed by two forms of programed forcing.

Bayesian algorithms for recovering structure from single-particle diffraction snapshots of unknown orientation: a comparison.

The advent of X-ray free-electron lasers promises the possibility to determine the structure of individual particles such as microcrystallites, viruses and biomolecules from single-shot diffraction snapshots obtained before the particle is destroyed by the intense femtosecond pulse. This program requires the ability to determine the orientation of the particle giving rise to each snapshot at signal levels as low as ~10(-2) photons per pixel. Two apparently different approaches have recently demonstrated this capability.