• Bulletin of the Korean Chemical Society
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• v.34 no.2
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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.

• Polymer(Korea)
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• v.34 no.2
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• pp.144-149
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• 2010

Ag/polystyrene(PS) nanocomposites were prepared by in situ reduction of silver 2-ethylhexylcarbamate (Ag-CB) complex and follwing radical polymerization only by heating at 110 $^{\circ}C$. In contrast to this conventional heating method, the microwave irradiation afforded well-dispersed silver nanoparticles(NPs) in styrene monomer without polymerization. The synthesis of Ag NPs proceeded uniformly throughout the reaction vessel only under microwave irradiation, completing the reaction simultaneously in the whole reaction solution. Successive polymerization of the monomer containing the resultant NPs has successfully produced a hybrid of the silver NPs dispersed in PS matrix. Ag/PS (0.1/100) nanocomposites were prepared successfully by melt-mixing process using Ag/PS(4.0/100) as a master-batch. UV-VIS spectroscopy, TEM, and X-ray diffraction techniques were used to investigate the process of formation of Ag/PS nanocomposites.

• Bulletin of the Korean Chemical Society
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• v.32 no.5
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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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• v.33 no.2
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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.