Figure 4. Spontaneous oil (n-hexane, dyed in blue) absorption/desorption of a 6/4 NS/p-PDMS during UV irradiation, and the origin of bubble growth with the oil desorption mechanism.

Oil desorption with UV irradiation time (a) 0 hr and (b) 8 hr, respectively. (c) Snapshot of oil/bubble release (~24 hr). (d) Top view of the collected oil/bubbles. The inset shows the side view of the collected oil/bubble. (e) Mass spectroscopy analysis of collected gas bubbles. (f) Mechanism of bubble growth and oil desorption with UV-responsive TiO₂ Scale bar, 1cm (a-d).