High Encapsulation Efficiency of Magnetite Nanoparticles in Hydrophobic Polymer Microcapsules using Microsuspension Conventional Radical Polymerization

Abstract

High encapsulation efficiency of magnetite nanoparticles (MNPs; Fe3O4) in microcapsules using PDVB as a hydrophobic polymer shell was successfully achieved by microsuspension conventional radical polymerization (ms CRP). MNPs were initially synthesized by co-precipitation of Fe2+/Fe3+ in a binary phase. During the nucleation of MNPs in alkaline aqueous solution existing oleic acid (OA), MNPs were coated with OA (MNPs-OA) before moving to the toluene phase with the addition of salt. At OA concentration of 0.3 wt%, most of the nucleated MNPs were hydrophobic and well dispersed in the toluene phase. Using DVB as a monomer for ms CRP, high encapsulation efficiency (92 %EE) of MNPs-OA was obtained, with low free polymer particle formation. By contrast, large amounts of free polymer particles were observed at low %EE (32%) of MNPs. The main driving force for high %EE was obtained by coating the surface of the MNPs by OA which increased hydrophobicity.

Novel reusablepH‐responsive photocatalyst polymeric microcapsules for dye treatment

“…Fe 3 O 4 nanoparticles were observed by TEM (Figure 4A). Furthermore, the XRD pattern of the obtained Fe 3 O 4 (Figure 4B) exhibited main diffraction peaks at 30°, 35°, 44°, 53°, 57°, and 63° accounting for crystal planes of (220), (311), (400), (422), (511), and (440), respectively, corresponding with the other reports 33,41 confirming the existence of Fe 3 O 4 . Moreover, Fe 3 O 4 nanoparticles moved to the magnet when the external magnetic field was applied, as shown in Figure 4C.…”

“…Magnetite nanoparticles were prepared by co‐precipitation in binary aqueous and toluene phases 33 . First, the aqueous phase containing FeCl 2 and FeCl 3 (0.50 and 0.87 g, respectively) was prepared in 15 mL of water.…”

Composite polymer particles containing bismuth vanadate particles for self-cleaning fabrics

“…Therefore, to incorporate BiVO 4 particles into the polymer particles, the BiVO 4 particles must disperse well in the oil phase or monomer droplet during the polymerization. OA with an HLB value of about 1 is normally used as an emulsifier in an inverse (W/O) emulsion system [53] or surface coating of metal oxides [48,[54][55][56] to improve their hydrophobicity. Therefore, in this work, BiVO 4 particles were coated with OA.…”

“…Thereafter, this technique was useful for the encapsulation of various material cores with various polymer types [42–45]. To encapsulate the metal oxide into the capsule in the O/W emulsion system, the surface of the metal oxide was modified to present hydrophobicity before envelopment with the polymer shell [46–48]. The encapsulation efficiency significantly improved [48].…”

“…Thereafter, this technique was useful for the encapsulation of various material cores with various polymer types [42][43][44][45]. To encapsulate the metal oxide into the capsule in the O/W emulsion system, the surface of the metal oxide was modified to present hydrophobicity before envelopment with the polymer shell [46][47][48]. The encapsulation efficiency significantly improved [48].…”