One‐step production of polyelectrolyte nanoparticles

Abstract

AbstractNeutral polymeric nanoparticles have found many important applications in fields such as drug delivery, biosensing and environmental research. However, charged polymeric nanoparticles have not yet found such success mainly due to the multi‐step and time‐consuming conventional production route. An emulsification–evaporation method was described as a fast and reproducible way to obtain neutral polymeric nanosuspensions. We propose here, for the first time, to extend this method to the one‐step production of negatively charged polymeric nanoparticles. For this purpose, we compared different processes, namely sonication, shear mixing and elongational‐flow micromixing (μRMX), in order to produce polyelectrolyte nanoparticles (PNPs) of poly(styrene sulfonate). We found that only μRMX allowed the production of highly monodispersed PNPs. We also verified the decrease of nanoparticle size (from 300 to 150 nm) and polydispersity index by increasing the emulsification time and decreasing the polymer molecular weight. Finally, we observed and explained the causes of an unusual behavior: the sudden increase of PNP size after a given emulsification time when using μRMX. © 2021 Society of Chemical Industry