Synthesis of Nanocapsules and Polymer/Inorganic Nanoparticles Through Controlled Radical Polymerization At and Near Interfaces in Heterogeneous Media

Abstract

This review article describes recent advances in the synthesis of polymeric nanocapsules and polymer/inorganic hybrid nanoparticles where controlled radical polymerization (CRP) has been used in (mini)emulsion systems to restrict the polymerization to an interface. For the synthesis of nanocapsules, CRP polymers stabilize the initial miniemulsion droplet interface and are chain extended mainly towards the center of the droplets comprising of an inert liquid core. In the encapsulation of inorganic particles, CRP polymers adsorbed on their surface are chain extended to form a polymer shell around the inorganic core. Precise control over the polymers' structures and compositions allows their location to be restricted to these interfaces. Polymerization in the subsequent (mini)emulsion system then commences from these specific locations courtesy of the reactivatable functions. The developed strategies retain the advantages of traditional emulsion or miniemulsion systems, while greatly expanding their potential to generate novel nanostructured functional materials.

Investigation of the Adsorption of Amphipathic macroRAFT Agents onto Montmorillonite Clay

“…BA units have also been incorporated in the copolymers in order to enhance the surface wettability for the monomer mixture in the subsequent REEP process, and promote encapsulation as previously reported in the literature. 16 The main characteristics of the macroRAFT agents synthesized in this work are displayed in Table 3.…”

Polymer-encapsulated γ-Fe 2 O 3 nanoparticles prepared via RAFT-mediated emulsion polymerization

“…Therefore, the next series of experiments were performed in semi-batch. Indeed, the process used for the encapsulation of inorganic particles in the presence of macroRAFT agents, either batch or semi-batch, has been shown to influence the overall mechanism of encapsulation [18][19][20]. As mentioned in the previous section, monomer droplets are present in a batch process and the macroRAFT agents may thus partition between the different phases.…”

“…The macroRAFT-mediated emulsion polymerization strategy offers a high degree of versatility with respect to the hydrophobic/hydrophilic composition and chemical nature of the macroRAFT agent, and was recently extended to the encapsulation of many kinds of inorganic particles or fillers [18][19][20] such as carbon nanotubes [21,22],…”

Controlling the Morphology of Film-Forming, Nanocomposite Latexes Containing Layered Double Hydroxide by RAFT-Mediated Emulsion Polymerization

“…Recent developments in controlled radical polymerization in aqueous dispersed systems, however, offer promise for overcoming these limitations. 23,24 We recently reported the synthesis of LDH/polymer nanocomposite particles 25 using a reversible addition-fragmentation chain transfer (RAFT)-mediated emulsion polymerization technique pioneered by Hawkett and co-workers. 26 Coined RAFT-assisted encapsulating emulsion polymerization (REEP), 26 the technique uses short, statistical copolymers synthesized by RAFT polymerization to stabilize nanoparticles in aqueous solution, and provide reactivatable groups from which polymer growth can occur in a subsequent emulsion polymerization step.…”