Polybead hollow microspheres (5.21% solids, 1 μm in diameter) anti-fade agent THF, mineral oil, and glycerol . Syringes (1 mL) and . Iron oxide nanoparticles of 30-nm diameter suspended in chloroform with oleic acid stabilization were purchased from Ocean Nanotech. Filters (5–8 μm) were purchased from Millipore.