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)@Fe3O4/Tannic acid@Ag (PS/P(DVB-co-MAA)@Fe3O4/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 (scCO2) 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 Fe3O4 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)@Fe3O4/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)@Fe3O4/TA@Ag nanocomposites can be recycled at least seven times and show no significant loss in catalytic performance.