Particle Size Control in Miniemulsion Polymerization via Membrane Emulsification

Abstract

Miniemulsion polymerization of methyl methacrylate has been conducted employing Shirasu porous glass (SPG) membrane emulsification for the generation of the initial miniemulsion. For the first time, submicron-sized monomer droplets and polymer particles have been prepared using membranes with pore sizes significantly smaller than those previously reported. Membrane pore sizes of diameters 100−400 nm were explored, demonstrating that the final particle size can be conveniently tuned within the diameter range of 250−1600 nm. The choice of radical initiator is crucial: a sufficiently hydrophobic initiator (lauroyl peroxide) is required to minimize the generation of bimodal particle size distributions via secondary nucleation. Given the advantages of low energy consumption, reduced shear stress (compared with conventional high-energy mixing approaches such as ultrasonication), and an easily adjustable particle size via the membrane pore size, membrane emulsification has significant potential for the synthesis of polymeric nanoparticles via miniemulsion polymerization.

Exploring Various Techniques for the Chemical and Biological Synthesis of Polymeric Nanoparticles

“…The co-stabilizer, initiator, surfactant, monomer mixture, and water are all required components for the mini-emulsion process. The utilization of a low-molecular-mass co-stabilizer as well as a high-shear device such as ultrasound in this approach [ 91 , 277 , 278 , 279 , 280 ] is the fundamental distinction between mini-emulsion polymerization and emulsion polymerization. The sort of co-stabilizer and initiator used has a big impact on how the NPs develop and what they look like.…”

The effect of surface-active statistical copolymers in low-energy miniemulsion and RAFT polymerization

“…19 To overcome these issues, low-energy methods have been developed including phase inversion composition, phase inversion temperature, membrane emulsification, in situ surfactant formation, bubble-bursting and spontaneous method. [23][24][25][26][27][28][29][30] It is noted that low-energy miniemulsions are rarely combined with controlled-radical polymerization strategies. 13,[31][32][33] Undoubtedly, Zetterlund and co-workers pioneered the field by reporting a low-energy emulsification method that involved the gradual dilution of a microemulsion precursor to form styrene nanodroplets with excellent particle size stability throughout the polymerization.…”

Droplet nucleation in miniemulsion thiol–ene step photopolymerization

“…Comparison of particle size (number) and droplet size (number) was exploited to evaluate qualitatively the extent of droplet and homogeneous nucleation. 41 However, a major problem is generally the lack of precision and accuracy in the determination of droplet and particle size distribution, possibly leading to erroneous conclusions about the nucleation mode. 42 To minimize interpretations errors, the size distribution determined by dynamic light scattering (DLS) was compared with the one given by transmission electron microscopy (TEM).…”