Soap-free synthesis for producing highly monodisperse, micrometer-sized polystyrene particles up to 6 μm

Yamada, Yasuyuki; Sakamoto, Takako; Gu, Shuangshuang; Konno, Mikio

doi:10.1016/j.jcis.2004.08.030

Cited by 42 publications

(24 citation statements)

References 27 publications

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“…On the other hand, soap-free emulsion polymerization, which has been used for the preparation of submicron-sized particles [6], is gentle on the environment because the polymerization is performed in water without surfactants. However, in recent research, micron-sized polymeric particles were synthesized using 2,2′-azobis [N-(2-carboxyethyl)-2-2-methylpropionamidine] hydrate (VA057) as a water-soluble initiator, even in soap-free emulsion polymerization [7][8][9].…”

Section: Introductionmentioning

confidence: 99%

Synthesis of micron-sized polymeric particles in soap-free emulsion polymerization using oil-soluble initiators and electrolytes

Yamamoto

2012

Colloid Polym Sci

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Soap-free emulsion polymerization of styrene using oil-soluble initiators and electrolytes was investigated to synthesize micron-sized polystyrene particles. It was clear that an oil-soluble initiator, such as AIBN, worked like a water-soluble initiator in soap-free emulsion polymerization of styrene to prepare monodispersed particles with negative charges, probably because of the polarization of the electron-attractive functional groups decomposed from the initiators and the pi electron cloud of benzene in a styrene monomer. The addition of an electrolyte enabled secondary particles to effectively promote hetero-coagulation for particle growth by reduction of an electrical double layer and prevention of self-growth. Changing the concentration and type of electrolyte enabled us to control the size up to 12 μm in soap-free emulsion polymerization of styrene using AIBN. Conventionally, organic solvents and surfactants have been used to prepare micronsized polymeric particles, but this method enabled the synthesis of micron-sized polymeric particles in water using electrolytes without surfactants.

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Section: Introductionmentioning

confidence: 99%

Synthesis of micron-sized polymeric particles in soap-free emulsion polymerization using oil-soluble initiators and electrolytes

Yamamoto

2012

Colloid Polym Sci

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“…4 Highly monodisperse PS spheres of narrow particle size distributions can be produced by one of the following three surfactant-free emulsion polymerization methods: (1) addition of an ionizable initiator, (2) use of surface active or amphoteric initiators. [5][6][7] Although a few papers have reported synthesis of nano-or micro-size PS spheres with respect to various reaction conditions such as initiator types, styrene concentration, stabilizer types and concentration, [8][9][10][11] still there is not enough understanding to control size and distribution for PS spheres by manipulating reaction parameters. When the relationship between these factors and size/distribution for the PS spheres is made clear, this technology can be commercially used in various fields.…”

Section: Introductionmentioning

confidence: 99%

Controlling Size and Distribution for Nano-sized Polystyrene Spheres

Yun¹,

Lee²,

Jang³

et al. 2010

Bulletin of the Korean Chemical Society

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Highly monodisperse polystyrene (PS) nanospheres were fabricated by surfactant-free emulsion polymerization in water using styrene, 2,2'-azobis(2-methyl propionamidine) dihydrochloride (AIBA), and poly(vinyl pyrrolidone) (PVP). The size and distribution of the PS nanospheres were systematically investigated in terms of initiator concentration, stabilizer concentration, reaction temperature, reaction time, and reactant concentration. With increasing AIBA initiator concentration, PS particle sizes are raised proportionally, and can be controlled from 120 to 380 nm. Particle sizes were reduced with increasing PVP concentration. This decrease occurs because a high PVP concentration leads to a large number of primary nuclei in the early stage of polymerization. When the reaction temperature increased, the sizes of the PS particles decrease slightly. The particles grew quickly during the initial reaction stage (1-3 h) and the growth rate became steady-state after 6 h. The PS sizes approximately doubled when the reactant (styrene, PVP, azo-initiator) concentrations were increased by a factor of eight.

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“…To study the effect of the concentration of V-501, C i , on particle properties, SFEPs of styrene were carried out changing C i at the constant concentrations of styrene monomer and AIBN. The reason why V-501 was selected was that the particles were synthesized in the SFEP using watersoluble initiator with carboxyl groups at high pH because of ionized initiator radicals derived from the initiators (Gu S. et al, 2004;Moribe H. et al, 2011;Yamada Y. et al, 2005). It was confirmed that the particles were not able to be formed independently by V-501 in normal water.…”

Section: Size Control Using Oil-and Water-soluble Initiators In Sfepmentioning

confidence: 99%

“…et al, 1986;Ugelstad J. et al, 1992). Recently, using 2,2'-azobis[N-(2-carboxyethyl)-2-2-methylpropionami dine] hydrate as a water-soluble initiator in SFEP enabled to synthesize micron-sized polymeric particles (Gu S. et al, 2004;Gu S.C. et al, 2002;Yamada Y. et al, 2005). Thus, the size of polymeric particle was controlled by the various polymerization methods.…”

Section: Introductionmentioning

confidence: 99%

Size Control of Polymeric Particle in Soap-Free Emulsion Polymerization

Yamamoto

Higashitani

2018

KONA

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The process of synthesis of polymeric particle in soap-free system was observed in-situ on the molecular scale by using an atomic force microscope (AFM). Using cationic water-soluble initiators enabled all of the polymeric materials to be adsorbed on the mica surface electrostatically. This adsorption technique of polymeric materials in the bulk obtained the AFM images of them throughout the reaction and to discuss the real growth mechanism of polymeric particles. The followings are found; the polymeric materials are continuously generated in the bulk throughout the reaction; and they make a contribution to the particle growth. Furthermore, soap-free emulsion polymerization (SFEP) of aromatic vinyl monomer using oil-soluble initiators was studied to synthesize micronsized particles. Oil-soluble initiator, such as AIBN, worked like a water-soluble initiator in SFEP to prepare monodispersed particles with negative charges, probably because of the pi electron cloud of phenyl ring in a monomer. The addition of an electrolyte enabled secondary particles in the bulk to enhance hetero-coagulation rate for particle growth. Changing the concentration and valence of electrolyte enabled us to control the size in SFEP using AIBN. These methods enabled reaction time to be reduced for the synthesis of micron-sized polymeric particles in soap-free system.

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Soap-free synthesis for producing highly monodisperse, micrometer-sized polystyrene particles up to 6 μm

Cited by 42 publications

References 27 publications

Synthesis of micron-sized polymeric particles in soap-free emulsion polymerization using oil-soluble initiators and electrolytes

Synthesis of micron-sized polymeric particles in soap-free emulsion polymerization using oil-soluble initiators and electrolytes

Controlling Size and Distribution for Nano-sized Polystyrene Spheres

Size Control of Polymeric Particle in Soap-Free Emulsion Polymerization

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