2.2. Preparation of Janus emulsionsThe surfactants and the dye were dispersed in oil (3 wt% PC,2 wt% ASO at 40◦C for 2 h in ultrasonic bath) and in water (4 wt%Tween 80, 2 wt% ASO, 2 wt% LEC) before the emulsification pro-cess starts. One gram emulsion contains 0.25 g olive oil, 0.25 gsilicone oil and 0.5 g water. The emulsification was made in one-step in a 10 ml glass tube by mixing with Minishaker IKA (Roth®)at 2500 rpm.