Solvent‐Free Synthesis of PMMA Particles using Tandem Acoustic Emulsification

Abstract Poly(methyl methacrylate) (PMMA) colloidal particles are nowadays extensively used in several applications and more specifically in nanotechnology. Challenges are focused on the green synthesis process leading to size‐controlled particles. In the present work, PMMA particles were successfully synthesized using tandem acoustic emulsification in water without organic solvent, and cross‐linkers. 2,2′‐azobis(2‐methylpropionamidine) dihydrochloride (AIBA) or ammonium persulfate (APS), were used as initiators. Parameters leading to size control were clearly identified. Consequently, the cooling rate of the solution after polymerization time appears dominating. Particle size distribution was monodispersed for both initiators. A nonionic surfactant, Tween 20, was also added, leading to a decrease in size particle and an increase in synthesis yield. Depending on the chemical groups provided by the initiator, PMMA particles appear negatively or positively charged. These charges located on the particle surface led to stable particle dispersion by limiting aggregation phenomena. Tunable surface charge was confirmed across the elaboration of coatings only made of PMMA particles, using conventional techniques wherein charged species are needed (Layer‐by‐Layer assembly and electrophoretic deposition). PMMA particles were also labelled using fluorescent dyes. Fluorescein and Nile Blue A were loaded during the polymerization process to ensure a homogeneous distribution of the dyes within the particles.