Surface Nucleation-Induced Raspberry-like PVDF@P(St-co-MPS-co-AA) Core–Shell Latex Particles via Seeded Emulsion Polymerization and Their High Efficiency for Confined Crystallization of PVDF in Nanospheres

Abstract

A novel complex structure of raspberry-like PVDF@P­(St-co-MPS-co-AA) (poly­(vinylidene fluoride)@poly­(styrene-co-trimethoxysilyl propyl methacrylate-co-acrylic acid)) core–shell particles combined with a popcorn-like shape has been successfully fabricated in substantial quantities via emulsifier-free seeded emulsion polymerization based on commercially available PVDF nanospheres. Scanning electron microscopy and transmission electron microscopy investigations suggest that polymerization temperature and addition of AA-catalyzed MPS hydrolysate dominate the formation of popcorn- or raspberry-like core–shell morphology. By tuning the polymerization temperature, it is possible to precisely control the hierarchical surface morphology of the composite particles, including the size and number of P­(St-co-MPS-co-AA) protrusions nucleated onto the PVDF seed surface. Furthermore, the cross-linking reaction induced by the MPS hydrolysate constrains the merging of P­(St-co-MPS-co-AA) bulges, effectively preventing the formation of exclusively eccentric core–shell particles. The complete wrapping of the PVDF seeds by the P­(St-co-MPS-co-AA) copolymer ensures three-dimensionally confined crystallization of PVDF in 180 nm nanospheres, exhibiting a higher encapsulation efficiency in comparison to the PVDF/PS system in the absence of the MPS hydrolysate. The confined crystallization in the complex latex nanospheres has significant implications for the production of polar crystalline phases in PVDF, leading to the coexistence of polar β/γ phases, with the β phase being predominantly dominant, instead of the typical α phase. The enhanced polar phases exhibited by the PVDF@P­(St-co-MPS-co-AA) core–shell particles imbue them with considerable potential for application as piezoelectric and ferroelectric materials, making them promising candidates for advanced technological utilization in various fields.

Design and Synthesis of Polystyrene-Occluded Reactive Core–Shell Particles of Natural Rubber to Balance Stiffness and Toughness in Poly(lactic acid)

“…In response to this, NR-based core–shell structures offer a promising avenue for achieving the desired stiffness–toughness balance. Seeded emulsion polymerization presents a valuable opportunity for precision in designing these particles. , It is noteworthy that NR derived from the Hevea tree (NR latex) offers ideal conditions for seeded emulsion polymerization and the formation of core–shell particles.…”