am6b00737_si_002.avi (1.71 MB)
Photothermal Breaking of Emulsions Stabilized with Graphene
media
posted on 2016-04-07, 00:00 authored by Matthew
D. J. Quinn, Khu Vu, Stephen Madden, Shannon M. NotleyPristine
graphene particles prepared using an aqueous phase exfoliation
technique have been used to promote the stabilization of emulsions
through adsorption at the oil–water interface. Highly localized
phase separation of these ultrastable emulsions could, however, be
induced through photothermal heating of the graphene particles at
the interface exposed to near-infrared light. The graphene wettability,
which is a key determinant in preventing droplet coalescence was altered
through the adsorption of nonionic block copolymer surfactants. Varying
the aqueous solution conditions influenced the hydration of the hydrophilic
component of the surfactant providing a further opportunity to alter
the overall particle wettability and, hence, stability of the emulsion.
In this way, highly stable-oil-in water emulsions were produced with
decane; however, water-in-oil emulsions were formed with toluene as
the oil phase.