Morphological Analysis of PSMA/PEI Core-Shell Nanoparticles Synthesized by Soap-Free Emulsion Polymerization.

Jae-Jung Park,Donghyun Kim,Yongsoo Kim,Wonjun Choi,Chanmin Lee,Jun-Young Lee,Ki-Seob Hwang,Hyukjun Kwon,Jung-Hyun Kim

doi:10.3390/nano11081958

Jae-Jung Park, Donghyun Kim + Show 7 more

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https://doi.org/10.3390/nano11081958

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Abstract

Emulsion polymerization presents the disadvantage that the physical properties of polymer particles are altered by surfactant adsorption. Therefore, in the soap-free emulsion polymerization method, a hydrophilic initiator is utilized while inducing repulsion among particles on the polymer particle surface, resulting in stable polymer particle production. In this study, we developed a methodology wherein spherical and uniform poly(styrene-co-maleic anhydride) (PSMA)/polyethyleneimine (PEI) core–shell nanoparticles were prepared. Further, their morphology was analyzed. During PSMA polymerization, the addition of up to 30% maleic anhydride (MA) resulted in stable polymerization. In PSMA/PEI nanoparticle fabrication, the number of reactants increased with increased initial monomer feed amounts; consequently, the particle size increased, and as the complete monomer consumption time increased, the particle distribution widened. The styrene (St) copolymer acted as a stabilizer, reducing particle size and narrowing particle distribution. Furthermore, the monomers were more rapidly consumed at high initiator concentrations, irrespective of the initiator used, resulting in increased particle stability and narrowed particle distribution. The shell thickness and particle size were PEI feed ratio dependent, with 0.08 being the optimal PEI-to-MA ratio. The fabricated nanoparticles possess immense potential for application in environmental science and in chemical and health care industries.

Highlights

The synthesis of nanoparticles is a complex process; single nanoparticles were the focus of research in the early days, but since the late 1980s, studies have found that hybrid or complex colloid particles have a higher efficiency
A novel bimodal peak corresponding to the reaction between the amine and carboxyl groups is detected at 163–172 ppm for poly(styrene-co-maleic anhydride) (PSMA)/PEI core–shell nanoparticles
The number of reactants participating in the reaction increased depending on that of the initial monomer feed, with an increase in the particle size

Summary

Introduction

The synthesis of nanoparticles is a complex process; single nanoparticles were the focus of research in the early days, but since the late 1980s, studies have found that hybrid or complex colloid particles have a higher efficiency. To enhance the properties of these materials, multilayered nanoparticles have been synthesized since the early 1990s, during which the term “core–shell” was introduced. Composite nanoparticles and core–shell particles are composed of at least two materials [1,2,3,4,5,6]. The characteristics of core–shell nanoparticles can be regulated by modifying the components and the composition ratio of the core to shell materials [15,16,17,18]

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