Exploration of the Mechanism for Self-Emulsion Polymerization of Amphiphilic Vinylpyridine

Abstract

A rare self-assembly behavior is observed in a hydrophilic monomer (4-vinylpyridine) (4VP) when polymerized in water with a hydrophilic initiator that results in the production of monodisperse polymeric nanoparticles in a single step. This behavior mimics the behavior obtained with the more commonly reported amphiphilic block copolymers. The synthesis and self-assembly of homopolymer nanoparticle from 4VP without the use of any cross-linker, stabilizing agent, surfactant, or polymeric emulsifier are described along with fundamental aspects of the mechanism of this polymerization. This facile and robust procedure enabled the production of highly monodisperse P4VP nanoparticle with a tunable size ranging from 80 to 445 nm. For the first time, we have investigated the growth mechanism of these polymeric nanoparticles to clarify the mechanism of polymeric nanoparticle formation. This work also provides direct visible evidence through transmission electron microscopy (TEM) images at the nanometer scale, which helps in obtaining a better understanding of the mechanism of self-assembly. The effect of temperature on the size of the polymeric nanoparticles was also examined along with the effect of initiator, monomer, and solvent concentrations. We therefore report a versatile and scalable process for the production of monodisperse polymeric nanoparticles, which we call self-emulsion polymerization (SEP).

Directed Assembly of Vesicle-Templated Polymer Nanocapsules under Near-Physiological Conditions

“…PDI in the observed range is typically indicative of a narrow size distribution. 26,49 No evidence of large aggregates was found for acrylic monomers at various temperatures ( Figure S1A), but DLS of catanionic vesicles loaded with styrene monomers showed a small number of aggregates under the same conditions ( Figure S1B). These data are consistent with our previous report showing a loaded vesicle phase in the greater concentration/surfactant ratio ranges for acrylic monomers compared to styrene monomers.…”

Surface activity of amphiphilic cationic pH-responsive poly(4-vinylpyridine) microgel at air/water interface

“…Poly(4-vinyl pyridine) (p(4-VP)) in the network structure can be synthesized in forms with homo or copolymeric nature by different monomers of various sizes e.g., in bulk at macro, and micro and nanometer scales [11][12][13][14][15]. The micro and nano size particles are commonly synthesized via microemulsion polymerization (MEP) [16], surfactant-free emulsion polymerization technique, suspension polymerization and so on [13,17]. Surfactant-free emulsion polymerization (SFEP) is an advantageous polymerization technique due to use of environmentally friendly solvents (e.g., water) without any impurities coming from surfactants, low viscosity, and with efficient heat removal capabilities [18,19].…”

Self-assembly phenomena of the brush-like amphiphilic organopolysiloxanes in aqueous solution

“…In addition, most of the hydrophilic side‐chains would only locate outside of the assemblies, and the polymers that possessed more side‐chains could form the assemblies of higher hydrophilicity with the out layers of denser side‐chains, which made the relative insensitiveness of the assembly size to the side‐chain content. It is well‐known that the increase of the nanostructural size would exacerbate the turbidity of the solution system . The interesting discovery was that when the size of the assemblies in the solution was not increased significantly, the visible clearness of the solution was sensitive to the hydrophilicity of the assemblies and the solution system could become crystal clear by increasing the hydrophilicity.…”