An experimental study on emulsion polymerization for formation of monodisperse particles smaller than 50 nm

Ishii, Haruyuki; Nakazawa, Hiroyuki; Kuwasaki, Naoto; Nagao, Daisuke; Konno, Mikio

doi:10.1007/s00396-022-04942-w

Cited by 4 publications

(2 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is possible that the self-nucleation of hydrophilic monomers selectively and competitively occurs (e.g., MMA); this can impart polydispersity within the product. The charged oligomers can behave in a similar manner to surfactants, whose concentration and critical micellization concentration (CMC) are likely a key factor in monomer conversion, particle size, and polydispersity. , The monomer conversion increased with the VBTMAC ratio, and narrow size distributions ( C v ≤ 10%) were obtained at a VBTMAC ratio between 0.0083 and 0.0323 (Figure ). It is possible that the presence of a cationic monomer could promote the ADIP-initiated polymerization during the initial phase of the reaction, whereas the addition of a cationic comonomer can increase the ionic strength of the reaction medium, which in turn weakens the electrostatic interaction between the oligomers and the charged nuclei.…”

Section: Results and Discussionmentioning

confidence: 99%

“…Soap-free emulsion polymerization was conducted on the basis of the methodology reported in a previous study. − All polymerization processes were performed in a half-liter reactor, using four baffles (0.7 cm in width) and a four-blade-pitched paddle impeller (5.0 cm in length). Deionized water was poured into the reactor and subsequently placed in a constant-temperature bath.…”

Section: Materials and Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Surface Characteristics of Antibacterial Polystyrene Nanoparticles Synthesized Using Cationic Initiator and Comonomers

Suga

Murakami

Nakayama

et al. 2022

ACS Appl. Bio Mater.

Self Cite

View full text Add to dashboard Cite

Polymer nanoparticles have attracted attention as antibacterial materials, but the function of the polymer itself has not yet been clarified sufficiently. To estimate the essential surface properties of antibacterial polymer nanoparticles, herein, we synthesized cationic polystyrene (PSt) nanoparticles via soap-free emulsion polymerization using 2,2′-azobis-[2-(1,3-dimethyl-4,5-dihydro-1H-imidazol-3-ium-2-yl)]propane triflate (ADIP) as initiator. The conversion of total monomers was drastically increased through the addition of the commoner (vinylbenzyl)trimethylammonium chloride (VBTMAC), where unimodal size distributions (C v ≤ 10%) were obtained at comonomer molar ratios between 0.0083 and 0.0323. The adsorption behavior of a solvatochromic anionic fluorescent dye revealed the surface charge density (σ) and affinity with anionic molecules (K) of PSt nanoparticles. The PSt nanoparticles with increased K values exhibited antibacterial activity against Staphylococcus epidermidis, with a minimum inhibitory concentration of at least 0.69 mg/mL. To determine a plausible mechanism for the antibacterial activity, the membrane damage induced by PSt nanoparticles was evaluated using an assay utilizing polydiacetylene vesicles as the model for negatively charged bilayer membranes. The PSt nanoparticles exhibiting large K values disturbed the bilayer structure of the model membrane system, suggesting that the synthesized PSt nanoparticles could be utilized as a contact-killing antibacterial agent.

show abstract

Section: Results and Discussionmentioning

confidence: 99%