• Bulletin of the Korean Chemical Society
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• 제34권2호
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• pp.505-509
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• 2013

A low temperature ($65^{\circ}C$) thermal deposition process was developed for depositing a silver coating on thermally sensitive polymeric substrates. This low temperature deposition was achieved by chemical reduction of a silver alkylcarbamate complex with latent reducing agent. The effects of acetol as a latent reducing agent for the silver 2-ethylhexylcarbamate (Ag-EHCB) complex and their blend solutions were investigated in terms of reducing mechanism, and the size and shape of silver nanoparticles (Ag-NPs) as a function of reduced temperature and time, and PVP stabilizer concentration were determined. Low temperature deposition was achieved by combining chemical reduction with thermal heating at $65^{\circ}C$. A range of polymer film, sheet and molding product was coated with silver at thicknesses of 100 nm. The effect of process parameters and heat treatment on the properties of silver coatings was investigated.

• 폴리머
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• 제34권2호
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• pp.144-149
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• 2010

Ag/polystyrene(PS) 나노복합체를 110 $^{\circ}C$의 가열법에 의하여 silver 2-ethylhexylcarbamate(Ag-CB) 복합체의 환원과 동시에 라디칼 중합을 진행하여 제조하였다. 또한, 이러한 전통적인 가열법과는 대조적으로 마이크로파를 조사하여 스티렌 단량체의 중합이 진행됨이 없이 은 나노입자가 잘 분산된 콜로이드 스티렌 용액을 제조할 수 있었다. 이렇게 단지 마이크로파를 조사하여 은 나노입자를 제조하는 방법은 반응기 내의 전체 용액 속에서 균일하고 빠르게 진행되어 매우 입자가 작고 균일한 은 나노콜로이드 용액을 제조할 수 있었다. 또한, 연속적으로 얻어진 은 나노입자를 포함하는 단량체 용액을 라디칼 중합시킴으로써 PS 고분자 매트릭스에 은 나노입자가 잘 분산된 Ag/PS 나노복합체를 얻을 수 있었다. Ag/PS(0.1/100) 나노복합체는 Ag/PS(4.0/100)를 마스터배치로 사용하여 용융-혼합 방법에 의하여 성공적으로 제조할 수 있었으며 그러한 나노복합체를 UV-VIS spectroscopy, TEM, 그리고 XRD를 이용하여 확인하였다.

• Bulletin of the Korean Chemical Society
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• 제32권5호
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• pp.1583-1586
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• 2011

Silver nanoparticles (<10 nm) were prepared in ultrasonic vibration-induced nanodroplets of isopropyl alcohol (IPA) in combination with hydrophobic room temperature ionic liquids (RTILs). The Ag-precursor used were silver (I) complex, Ag$_2$(ehac)$_2$(eha)$_2$ (ehac = 2-ethylhexylammonium carbamate; eha = 2-ethylhexylamine), in IPA, while 1-butyl-3-methylimidazolium-based ionic liquids bearing $SbF_6^-$, $PF_6^-$ and $NTf_2^-$ as counter anions were used as RTILs. During sonication for 10-90 min at room temperature, uniform silver nanoparticles with mean sizes of 2 to 8 nm were rapidly synthesized. Transmission electron micrographs also confirmed that silver nanoparticles have a spherical shape and diverse sizes depending on the reaction time (10-90 min).

• Bulletin of the Korean Chemical Society
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• 제33권2호
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• pp.483-488
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• 2012

We successfully decorated multi-wall carbon nanotubes (MWNTs) with silver by reacting Ag-NPs with thiolfunctionalized MWNT-SH. Ag alkylcarbamate complex was used as an Ag precursor. Uniform Ag-NPs (5-10 nm) were effectively prepared by microwaving within 60 s using 1-amino-4-methylpiperazine (AMP), which acts as a reaction medium, reducing agent, and stabilizer. The MWNTs were functionalized with 2-aminoethanethiol. Exploiting the chemical affinity between thiol and Ag-NPs, Ag-MWNT nanohybrids were obtained by spontaneous chemical adsorption of MWNT-SH to Ag through Ag-S bonds. The Ag-S-MWNTs were characterized by TGA, XRD, and TEM to confirm that Ag-NPs were uniformly decorated onto the MWNTs. The Ag-S-MWNTs were then employed as conducting filler in epoxy resin to fabricate electrically conducting polymer composites. The electrical properties of the composites were measured and compared with that containing MWNT-SH. The electrical conductivity of composites containing 0.4 wt % Ag-S-MWNT was four orders of magnitude higher than those containing same content of MWNT-SH, confirming Ag-S-MWNT as an effective conducting filler.