Quantifying the surface tension of non-equilibrium colloidal fluids

Through the use of a colloid-polymer system employing temperature-sensitive pNIPAM microgel colloidal particles, we observe the nucleation and dissolution of colloid-rich liquid droplets. We use light-sheet microscopy to observe the formation and dissolution of colloid-rich droplets in three-dimensions and with optical sectioning. Our colloid-polymer system allows us to precisely tune the equilibrium state--mixed or demixed--by adjusting the sample temperature. With videos obtained from the light-sheet microscope, we perform image analysis of fluctuating droplets to extract the surface tension.