Formation of n-Hexane-in-DMF Nonaqueous Pickering Emulsions: ABC Triblock Worms versus AB Diblock Worms

Abstract

Nonaqueous Pickering emulsions exhibit promising applications in many industrial areas but have been relatively less studied in the past. In this study, n-hexane-in-DMF nonaqueous Pickering emulsions stabilized by core cross-linked copolymer worms with mixed shells are demonstrated for the first time. Core cross-linked copolymer worms with mixed shells were prepared by seeded reversible addition–fragmentation chain transfer (RAFT) quasi-solution polymerization. Specifically, polystyrene-poly­(4-vinylpyridine) (PS-P4VP) diblock copolymer worms were first prepared via RAFT-mediated dispersion polymerization in toluene under the given conditions using PS as both the macro-CTA and the stabilizer block. After the chemical cross-linking of P4VP cores, PS-P4VP diblock copolymer worms were chain-extended with LMA in DMF/toluene (1:9, weight ratio) mixed solvents, producing core cross-linked PS-P4VP-PLMA worms with PS/PLMA mixed shells. The as-prepared core cross-linked PS-P4VP-PLMA worms with mixed PS/PLMA shells were further utilized as Pickering emulsifiers for the generation of nonaqueous n-hexane-in-DMF Pickering emulsions. The emulsifying performances of mixed-shell copolymer worms were compared with those of their spherical and linear analogues with entirely identical chemical compositions as well as PS-P4VP diblock copolymer worm precursors, respectively.

Seeded RAFT Polymerization‐Induced Self‐assembly: Recent Advances and Future Opportunities

“…It is expected that seeded PISA can overcome the limitations of traditional PISA and expand new horizons toward PISA. [67,[71][72][73][74][75][76][77][78][79][80][81] Briefly, two steps are involved in a typical seeded PISA that include the preparation of seeds via PISA and the subsequent chain extension under heterogeneous polymerization conditions, generating triblock or multiblock copolymer nanoparticles with unique morphologies and surface properties. In addition, seeded PISA also enables the control over the size of polymer particles.…”

Surface Wettability-Switchable Janus Fiber Fragments Stabilize Pickering Emulsions for Effective Oil/Water Separation

“…7 cores and polystyrene/poly(lauryl methacrylate) mixed shells, which could stabilize n-hexane-in-dimethylformamide Pickering emulsions. 8 In addition to the particle size, the geometry shape of solid particles plays vital roles in regulating the packing density, orientation at the interfaces, and stability of the emulsion droplets. Compared with the spheric counterpart, the stabilizing effect of nonspherical solid particles (e.g., flake and ellipsoid) is related with the different steric effect and capillary forces on the oil/water interface.…”

“…Different solid particles, such as latex particles, inorganic nanoparticles, and clay particles have been used to stabilize the interface of emulsions with a variety of functionalities . Sun et al prepared polymer worms containing cross-linked poly­(4-vinylpyridine) cores and polystyrene/poly­(lauryl methacrylate) mixed shells, which could stabilize n -hexane-in-dimethylformamide Pickering emulsions . In addition to the particle size, the geometry shape of solid particles plays vital roles in regulating the packing density, orientation at the interfaces, and stability of the emulsion droplets.…”

Stabilizing oil–oil interfaces with mixed-shell polymeric nanoparticles prepared via PISA and the grafting combination

“…Recently, several research groups have reported MSPN stabilized Pickering emulsions. [40][41][42][43] Studies revealed that MSPNs exhibited excellent emulsifying performances owing to adaptive wettability at liquid-liquid interfaces. Adaptive wettability benefited from the different affinities of shells to different phases.…”