• Macromolecular Research
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• 제14권2호
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• pp.194-198
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• 2006

Polystyrene, PS, particles of 450 nm diameter and poly(styrene-co-styrene sulfonate), PSS, particles of 140-160 nm diameter were prepared by emulsifier-free emulsion polymerization. The surfaces of the PS and PSS particles were coated with Ag nanoparticles for the application of antimicrobial agents by reduction of Ag ions using ${\gamma}$-irradiation. The Ag-PS and Ag-PSS were characterized by High-Resolution Transmittance Electron Microscopy (HR-TEM), Field-Emission Scanning Electron Microscopy (FE-SEM), and Energy Dispersive X-ray Spectroscopy (EDXS). The HR-TEM and EDXS data showed that the Ag nanoparticles were loaded on the surface of the PS and PSS particles, respectively. The antimicrobial efficiency of the Ag-PS and Ag-PSS particles (0.4 g) with ca. 100 ppm Ag, which was coated onto yam (KS K 0905-1996 rule), was tested against Staphylococcus aureus ATCC 6538 and Klebsiella pneumoniae ATCC 4352 after 100 washing cycles (KS K 0432-1999 rule). The antimicrobial efficiency of the Ag-PS particles against Staphylococcus aureus ATCC 6538 and Klebsiella pneumoniae ATCC 4352 was 99.9% after 100 cycles washing., confirming that the Ag-PS particles can be used as antimicrobial agents.

• Macromolecular Research
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• 제15권4호
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• pp.285-290
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• 2007

Ag nanoparticles were distributed onto polystyrene nanoparticle (PS-Ag) beads using two synthetic methodologies. In the first methodology, polystyrene (PS) beads were prepared via emulsion polymerization, with Ag nanoparticles subsequently loaded onto the surface of the PS beads. The polymerization of styrene was radiolytically induced in an ethanol (EtOH)/water medium, generating PS beads. Subsequently, Ag nanoparticles were loaded onto the PS beads via the reduction of Ag ions. The results from the morphological studies, using field emission transmission electron microscopy (FE-TEM), reveal the PS particles were spherical and nanosized, and the average size of the PS spherical particles decreased with increasing volume % of water in the polymerization medium. The size of the PS spherical particles increases with increasing radiation dose for the polymerization. Also, the amount of Ag nanoparticle loading could be increased by increasing the irradiation dose for the reduction of the Ag ions. In the second methodology, the polymerization of styrene and reduction of Ag ions were simultaneously performed by irradiating a solution containing styrene and Ag ions in an EtOH/water medium. Interestingly, the Ag nanoparticles were preferentially homogeneously distributed within the PS particles (not on the surface of the PS particles). Thus, Ag nanoparticles were distributed onto the surface of the PS particles using the first approach, but into the PS clusters of the particles via the second. The antimicrobial efficiency of a cloth coated with the Ag-PS composite nanoparticles was tested against bacteria, such as Staphylococcus aureus and Klebsiella pneumoniase, for 100 water washing cycles.

• Bulletin of the Korean Chemical Society
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• 제32권12호
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• pp.4221-4226
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• 2011

Honeycomb-patterned polyvinypyrrolidone (PVP) thin films coated with nanometer-sized silver particles were prepared using honeycomb-patterned polystyrene (PS) template films fabricated by casting a polystyrene solution under humid condition. Silver was first metallized on the patterned PS films via silver nitrate ($AgNO_3$) reduction using tetrathiafulvalene (TTF) and a small amount of PVP as the reductant and dispersing agent, respectively. The effects of $AgNO_3$, TTF, and PVP solution concentrations during the reduction process in acetonitrile were determined to obtain a uniform silver-coated honeycomb-patterned PS film. Second, the silver-metallized patterned porous PS films were filled with high PVP concentration solutions via the spincoating process. Silver-coated patterned PVP films were obtained by peeling off the PVP layer from the template PS film after drying. The results show that the honeycomb-patterned PVP films uniformly coated with silver particles are conveniently obtained using the silver-coated patterned PS template, although the direct fabrication of these films using water droplets under humid conditions was not feasible because of the water solubility of PVP.

• 분석과학
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• 제23권3호
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• pp.233-239
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• 2010

폴리스테린을 주형으로 사용하여 순수한 매크로포러스 실리카 지지체를 졸겔법에 의하여 제조하였으며, 은 입자가 매크로 기공 안에 균일하게 분산되어 있는 매크로포러스 은/실리카 복합소재를 성공적으로 제조하였다. 순수한 실리카 다공체는 폴리스테린 크기에 따라 100 nm와 200 nm의 균일한 기공을 가지고 있었으며 이는 폴리스테린의 크기에 따라 기공크기를 제어할 수 있었다. 매크로포러스 은/실리카 기공의 크기 제어와 $AgNO_3$의 농도에 따른 미세구조를 관찰한 결과 TEOS의 3 wt% $AgNO_3$를 사용한 것이 가장 이상적인 균일한 기공의 분포를 나타내었다. 매크로포러스 은/실리카 복합체는 100-200nm 균일한 기공을 가지고 있었으며, 지지체 내의 은 입자는 대략 15~20 nm 크기를 보여주었다.