RSC Chemical Dynamics Award Winner Seminar: “Phase separation and nucleation: from frustration to control”

Ever since it was suggested that the anomalous properties of liquid water could explained by an amorphous to amorphous liquid-liquid transition, the hunt has been on for other examples of such transitions. Surprisingly, only two other examples of liquid-liquid transitions were found in molecular liquids and even these are highly controversial. I will show that one of these (in n-butanol) is, in fact, a liquid crystal transition but one in which the liquid crystal is not “in between” the liquid and the crystal but instead frustrates the formation of the crystal. However, we are not content to just passively observe phase transitions but desire to gain control over the nucleation of new phases. I will show that concentration fluctuations in the neighbourhood of a liquid-liquid critical point can be harnessed by a laser-tweezing potential to induce concentration gradients that may trigger the nucleation of a new phase.