• Journal of the Korean Society of Industry Convergence
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• v.10 no.1
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• pp.27-32
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• 2007

It has been recently reported that the SERS (Surface Enhanced Raman Scattering) effect of the silver mirror substrate made by Tollen's method is much superior to that of other substrates. In this study, the experiments for comparison of surface enhancement of silver sol and silver mirror substrates were done, where we checked the characteristics of silver mirror substrate made by Tollen's method. The surface enhancement of fluorescein was analyzed by silver sol and silver mirror substrates. We observed the SERS spectra of fluorescein. The assignments of the vibrational bands shown in SERS spectra are given based on both literature and the semi-empirical calculations at the PM3 methods. The surface enhancement properties for fluorescein showed that the silver mirror was more superior to sliver sol substrates. Spectra of fluorescein revealed that fluorescein was adsorbed on silver surfaces by a common oxygen atom. According to the 'surface selection rule', the vibrations in the band intensities reflect the adsorption orientation of the molecule on to the surface of SERS substrates. Therefore, we deduced that the adsorption orientation of fluorescein was little tilted perpendicular to the silver surfaces by using of the surface selection rules.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.1552-1555
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• 2005

We have studied the inkjet patterning of synthesized aqueous silver nano-sol on interface-controlled ITO glass substrate. Furthermore, we designed the conductive ink for direct inkjet patterning on bare ITO glass substrate. The first, the highly concentrated polymeric dispersant-assisted silver nano sol was prepared by variation of molecular weight and control of initial nucleation and growth of silver nanoparticles. The high concentration of batch-synthesized silver nano sol was possible to 40 wt%. At the same time the particle size of silver nanoparticles was below $10{\sim}20nm$. The second, the synthesized silver nano sol was inkjet - patterned on ITO glass substrate. The connectivity and width of fine line depended largely on the wettability of silver nano sol on ITO glass substrate, which was controlled by surfactant. The relationship was understood by wetting angle. The fine line of silver electrode as fine as $50{\sim}100\;{\mu}m$ was successfully formed on ITO glass substrate. The last, the direct inkjet-patternable silver nano sol on bare ITO glass substrate was designed also.

• Journal of the Korean Ceramic Society
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• v.41 no.10 s.269
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• pp.788-791
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• 2004

We have studied the fabrication of silver micro lines using the silver nano sol on ITO substrate by an ink-jet method. The average particles size of $10wt\%$ silver nano sol synthesized with polyelectrolytes was smaller than 10 nm. The pattern formation of silver nano sol on the substrate closely related with the contact angle of the silver nano sol. The dot shaped of silver nano sol on bare ITO substrate was formed due to the high contact angle of silver nano sol. When ITO substrates was treated with 100 ppm polyethylenimine for silver nano sol patterning, fine silver micro lines of $60{\sim}100{\mu}m$ width was fabricated by ink-jet method.

• Bulletin of the Korean Chemical Society
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• v.24 no.11
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• pp.1599-1604
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• 2003

New methods were developed to prepare silver-doped sol-gel films for surface-enhanced Raman spectroscopy (SERS) applications. First, silver ions were doped into a sol-gel matrix. The doped silver ions were reduced into corresponding silver metal particles by two reductive procedures; chemical reduction and thermal reduction. The SERS spectra of benzoic acid were used to demonstrate the SERS effect of the new substrates. The adsorption strength of benzoic acid adsorbed on differently reduced substrates was discussed. The possible adsorption form and the orientation of adsorbate were also discussed.

• Journal of the Korean Ceramic Society
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• v.41 no.9
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• pp.670-676
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• 2004

The synthesis of highly concentrated silver nano sol assisted by polymeric dispersant (polyelectrolytes) for inkjet method was studied. The silver nano sol was prepared with AgNO$_3$, polyelectrolytes (HS5468cf ; polyacrylic ammonium salt), and reducing agent. The polyelectrolytes play an important role in formation of complex composed of Ag$\^$+/ion and carboxyl group (COO$\^$-/), result in preparation of highly dispersed silver nano particles. The optimization of added amount of polyelectrolytes, and concentration of silver nano sol was studied. The silver nanoparticles were evaluated by XRD, particle size/zeta potential analyzer and FE-TEM. The silver nanoparticles with the range of 10 nm in diameter were produced. The concentration of batch-synthesized silver nano sol was possible up to 40 wt%.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.913-918
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• 2005

It is expected that the inkjet technology offers prospect for reliable and low cost manufacturing of FPD (Flat Panel Display). This inkjet technology also offers a more simplified manufacturing process for various part of the FPD than conventional process. For example, recently the novel manufacturing processes of color filter (C/F) in LCD, or RGB patterning in OLED by inkjet printing method have been developed. This elaborates will be considered as the precious point of manufacturing process for the mass production of enlarged-display panel with a low price. On this point of view, we would like to review the status of inkjet technology in FPD, with some results on forming micro line by inkjet patterning of suspension type silver nano ink as below. We have studied the inkjet patterning of synthesized aqueous silver nano-sol on interface-controlled ITO glass substrate. Furthermore, we designed the conductive ink for direct inkjet patterning on bare ITO glass substrate. The first, the highly concentrated polymeric dispersant-assisted silver nano sol was prepared. The high concentration of batch-synthesized silver nano sol was possible to 40 wt%. At the same time the particle size of silver nanoparticles was below $10{\sim}20nm$. The second, the synthesized silver nano sol was inkjet - patterned on ITO glass substrate. The connectivity and width of fine line depended largely on the wettability of silver nano sol on ITO glass substrate, which was controlled by surfactant. The relationship was understood by wetting angle. The line of silver electrode as fine as $50{\sim}100\;{\mu}m$ was successfully formed on ITO glass substrate. The last, the direct inkjet-patternable silver nano sol on bare ITO glass substrate was designed also.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.981-984
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• 2004

We have studied a printability of synthesized silver nano solon ITO glass substrate. The highly concentrated polymeric dispersant-assisted silver nano sol was prepared by variation of molecular weight and control of initial nucleation and growth of silver nanoparticles, to achive dispersion stability and controlling the size of silver nanoparticles. The synthesized silver nano-sol was tested for printability to explore the possibility of micro-electrodes patterning on ITO glass substrate. The silver micro-electrode with 50${\sim}100{\mu}m$ line width was formed on ITO glass substrate.

• Bulletin of the Korean Chemical Society
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• v.9 no.1
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• pp.27-29
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• 1988

The surface-enhanced Raman scattering(SERS) of benzylcyanide in a silver sol was investigated. It was concluded that the molecule adsorbed onto the silver surface via the ${\pi}$ system of the CN group. The molecule was assumed to coordinate with either a single atom or two silver atoms. According to the SERS selection rule, the benzene ring of the adsorbed species seemed to assume a flat stance with respect to the silver surface.

• Bulletin of the Korean Chemical Society
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• v.16 no.2
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• pp.130-134
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• 1995

Surface-enhanced Raman (SER) scattering of 2-cyanonaphthalene (2-CN) has been investigated in silver sol. Addition of halide ions was needed to obtain authentic SER spectra of the molecule. The SER spectra thus obtained exhibited a slight but noticeable dependence on the kind of halide ions used. This halide-dependent spectral variation was attributed to the orientational change of molecule on silver sol surface. A possible mechanism for such an orientational change is proposed in terms of the competitive adsorption of 2-CN with halide ions on the so-called halide-specific sites.

• Bulletin of the Korean Chemical Society
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• v.9 no.5
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• pp.311-317
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• 1988

The surface-enhanced Raman scattering(SERS) of methoxybenzonitrile in a silver sol was investigated. All of ortho-, meta-, and para-substituted benzonitriles were found to adsorb on the silver surface via the nitrogen lone pair electrons. The benzene ring of meta derivative seemed likely to stand perpendicular to the silver surface, while the benzene rings of both otho and para derivatives assumed tilted stances with respect to the surface. The SERS technique appeared to be a useful means to study the substituent electronic effects.