Exploring the conformational dynamics of alanine dipeptide in solution subjected to an external electric field: A nonequilibrium molecular dynamics simulation

In this paper, we investigate the conformational dynamics of alanine dipeptide under an external electric field by nonequilibrium molecular dynamics simulation. We consider the case of a constant and of an oscillatory field. In this context we propose a procedure to implement the temperature control, which removes the irrelevant thermal effects of the field. For the constant field different time-scales are identified in the conformational, dipole moment, and orientational dynamics. Moreover, we prove that the solvent structure only marginally changes when the external field is switched on. In the case of oscillatory field, the conformational changes are shown to be as strong as in the previous case, and non-trivial nonequilibrium circular paths in the conformation space are revealed by calculating the integrated net probability fluxes.Comment: 23 pages, 12 figure

Janus Colloidal Matchsticks

We fabricated chemically and shape-anisotropic colloids composed of silica rods coated with gold tips using a multistep process involving electric-field alignment and crystallization, microcontact printing, and selective metallization. Through direct observation, we found that these "Janus matchsticks" self-assemble into multipods (bi-, tri-, and tetrapods) of varying coordination number and patch angle in aqueous solution