Using supercritical carbon dioxide to synthesize polymer nanospheres with an open hole on the surface and the application of spatially structured PS/P(DVB-co-MAA)@Fe3O4/TA@Ag nanocomposites

Porous nanospheres have potential applications in reactions, catalysis and water treatment because of their high surface area, low density and high loading capacity. In this work, a reproducible and well-controlled way to fabricate hollow Polystyrene/Poly(divinylbenzene-co-methacrylic acid)@Fe 3 O 4 /Tannic acid@Ag (PS/P(DVB-co-MAA)@Fe 3 O 4 /TA@Ag) nanocomposites with high catalytic efficiency is developed. Firstly, hollow Polystyrene/Poly(divinylbenzene-co-methacrylic acid) (PS/P(DVB-co-MAA)) nanospheres with an open hole on the surface are produced by supercritical carbon dioxide (scCO 2 ) rapid depressurization methodology. The consequence shows that structure of polymer nanospheres is controllable by altering the reactive conditions, like temperature, pressure, solvent ratio, degree of cross-linking and time. Secondly, the magnetic Fe 3 O 4 and Ag nanoparticles are deposited onto the surface of hollow PS/P(DVB-co-MAA) nanospheres. The result indicates that hollow PS/P(DVB-co-MAA)@Fe 3 O 4 /TA@Ag nanocomposites are highly efficient in degrading dyes, displaying that the apparent rate coefficients of methylene blue (MB), rhodamine B (RhB) and 4-nitrophenol (4-NP) reduction are .0090 s −1 , 0.0239 s −1 , and 0.0073 s −1 , respectively. Besides, hollow PS/P(DVB-co-MAA)@Fe 3 O 4 /TA@Ag nanocomposites can be recycled at least seven times and show no significant loss in catalytic performance.