Reversible addition–fragmentation chain transfer (RAFT) emulsion polymerization is a powerful tool for polymer encapsulation of pigment nanohybrids. Conventional RAFT emulsion polymers, however, contain sulfur residues that contribute to undesired odor and deleterious effects on final materials. Our strategy relies on an amphiphilic macromonomer poly­(methacrylic acid-co-methyl methacrylate) P­(MAA-co-MMA) with an ω-unsaturated end group synthesized in situ via cobalt­(II)-mediated catalytic chain transfer polymerization (CCTP) at the surface of C.I. Pigment Blue 15:3 (PB) particles. Subsequently, these macromonomers are used as the living points to mediate the in situ sulfur-free RAFT (SF-RAFT) emulsion polymerization of monomers (butyl methacrylate (BMA) and butyl acrylate (BA)). It was found that a well-controlled polymerization process was achieved by semibatch SF-RAFT emulsion polymerization on the PB surface, as evidenced by the smooth increase in the molecular weight of polymer chains as the polymerization progressed and by transmission electron microscopy (TEM) results. Due to the sealing effect, these polymer/PB hybrid particles exhibited excellent colloidal stability in the aqueous phase. More importantly, film-forming hybrid particles with a soft P­(BMA-co-BA) shell were successfully prepared in this work, which suggested that SF-RAFT-mediated polymerization may offer a useful alternative approach to traditional RAFT emulsion polymers for the preparation of organic/inorganic nanohybrids.

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The stimuli-responsive circularly polarized luminescence (CPL) property is highly desirable in the development of advanced multifunctional optical materials. However, the fabrication of CPL solid materials showing stimuli-responsive behavior in terms...

Reversible addition−fragmentation chain-transfer (RAFT)-mediated hybrid emulsion polymerization is an in situ growth method of increasing interest for preparation of colloidal polymers/inorganic hybrid latex with precise structures and properties. However, the challenges of the conventional organic sulfur-based RAFT agents causing color and undesired odor problems still attract attention. In response to this problem, herein, a cationic amphipathic statistic sulfur-free (SF) macro-RAFT agent with a vinyl end group is proposed to disperse organic pigment particles (C.I. Pigment Red 170), where the vinyl group is the living point to regulate the sulfur-free and surfactant-free RAFT hybrid emulsion polymerization of methyl methacrylate (MMA) or MMA with butyl acrylate (BA). Benefitting from this SF macro-RAFT agent acting as both coupling agent and stabilizer, the "living" chain growth of the polymers onto the C.I. Pigment Red 170 surface causes the formation of encapsulating pigment hybrid particles as proven by size-exclusion chromatography and transmission electron microscopy analyses. As a proof-of-concept experiment, the film-forming P(MMA-co-BA)/pigment hybrid latex particles are applied to textile colorants to pad dyeing cotton fabric. Owing to the unique structure of hybrid particles with high pigment content (81.3%), the dyed cotton fibers exhibit high color strength, dryand wet-rubbing fastness, good air permeability, and softness in comparison with the traditional mixture system. This study will not only broaden the area of RAFT-mediated hybrid emulsion polymerization for preparing hybrid particles but also provide a facile application for clear production.

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