Alessandro Magazzù has been awarded a best oral contribution “Soft Matter poster price” during the conference Italian Soft Matter Days 2018, held in Padua, Italy on September 13-14, 2018. The prize has been given by Emanuela Zaccarelli, editorial board members of the Soft Matter journal. This prize mainly consists in an invitation to submit a manuscript without the pre-screening by the Editors. It also includes a “poster prize” and a personal yearly subscription to the journal.
Controlling the dynamics of colloidal particles by critical Casimir forces
Alessandro Magazzù, Agnese Callegari, Juan Pablo Staforelli, Andrea Gambassi, Siegfried Dietrich & Giovanni Volpe
We measure the time evolution of the distance between the two colloids to determine their relative diffusion and drift velocity. Furthermore, we show how critical Casimir forces change the dynamic properties of this two-colloid system by studying the temperature dependence of the distribution of the so-called first-passage time, i.e., of the time necessary for the particles to reach for the first time a certain separation, starting from an initially assigned one. These data are in good agreement with theoretical results obtained from Monte Carlo simulations and Langevin dynamics.
Microscopic engine powered by critical demixing
Alessandro Magazzù, Falko Schmidt, Agnese Callegari, Luca Biancofiore, Frank Cichos & Giovanni Volpe
Italian Soft Days 2018, Padua, Italy
13-14 September 2018
We propose a new type of engine powered by the local, reversible demixing of a critical binary liquid. In particular, we show that a light absorbing, optically trapped particle, performs revolutions around the trapping beam producing work.
This behavior results from an equilibrium between optical forces and diffusiophoresis induced by a local demixing of the critical mixture. This new kind of engine can be controlled by the optical power supplied, the temperature of the environment and the criticality of the system.