Fabrication of amphiphilic porous PDVB-PAA Janus nanoparticles: Formation mechanism, simultaneous loading and regulated release of hydrophobic and hydrophilic cargos

In this work, we reported the amphiphilic porous polydivinylbenzene-poly(acrylic acid) (PDVB-PAA) Janus nanoparticles (NPs) with a cross-linked hydrophobic porous PDVB framework and a cross-linked hydrophilic porous PAA bulge, which were converted from polystyrene/polydivinylbenzene-poly(tert-butyl acrylate) (PS/PDVB-PtBA) Janus NPs via hydrolysis in dichloromethane. Cl,Br-labeled PS/PDVB-PtBA Janus NPs were designed and synthesized to experimentally verify the formation mechanism of PS/PDVB-PtBA Janus NPs and PDVB-PAA Janus NPs for the first time by combined techniques of TEM, SEM with element mapping and FTIR measurements. By simply varying the feeding amount of crosslinking agent ethylene glycol dimethacrylate (EGDMA) during the polymerization step of tBA, the morphologies of resultant PS/PDVB-PtBA Janus NPs and corresponding PDVB-PAA Janus NPs could be well controlled. It was demonstrated that the obtained amphiphilic porous PDVB-PAA Janus NPs could be applied as carrier materials for simultaneously loading hydrophobic coumarin 153 and hydrophilic rhodamine 6G.