• 열처리공학회지
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• 제18권4호
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• pp.242-246
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• 2005

Silver nanoparticles were synthesized by liquid phase reduction method from aqueous silver nitrate solution and borohybride as a reduction agent. The morphology, particle size and shape were influenced by the reaction conditions such as the concentration of $AgNO_3$, a reduction agent and addition of surfactant. The particle size decreased with decreasing the concentration of silver nitrate and using a borohydride. The obtained Ag particles showed the spherical shape with the range of 10-20 nm.

• Bulletin of the Korean Chemical Society
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• 제33권12호
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• pp.3987-3992
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• 2012

Silver nanopowders were prepared from silver 2-ethylhexylcarbamate (Ag-EHCB) complexes by simple thermal reduction at $85^{\circ}C$ without any reducing agent in organic solvent. 2-Ethylhexylammonium 2-ethylhexylcarbamate (EHAEHC) was investigated in terms of their abilities to stabilize the silver nanoparticles (Ag-NPs) and its subsequent effects on the preventing aggregation between Ag-NPs. Conditions (concentration of stabilizer and reaction time) used to reduce Ag-EHCB complex were systematically varied to determine their effects on the sizes of Ag-NPs. The formation of the stabilized Ag-NPs were easily monitored by UV-vis spectroscopy and characterized by TGA, TEM, SEM and XRD. When EHAEHC was used as a stabilizer, Ag-NPs of 10-30 nm in diameter were easily obtained in high yield. Silver patterns were obtained from a silver nano-paste by heat treatment at $200^{\circ}C$ in air and were found to have resistivity values of $2.9{\times}10^{-8}\;{\Omega}{\cdot}m$.

• Macromolecular Research
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• 제10권2호
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• pp.80-84
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• 2002

Silver species other than the silver ion were formed by UV irradiation on polymer electrolyte membranes containing silver salts and their effect on complexation behavior between the silver and olefin was investigated through the separation performance of olefin/paraffin mixtures. The ideal propylene/propane separation factor reached 350 and the separation coefficient was ca.15 due to the high loading amount of silver ions into poly(2-ethyl-2-oxazoline) (POZ) without UV irradiation. On UV irradiation either in air or under nitrogen, the silver-POZ membranes became yellow-brown initially due to the formation of colloidal silver particles, and finally black and metal-like luster. Even when Ag$^{+}$ was converted, to some extent, to Ag$^{\circ}$ by UV irradiation in air at the early stage, the separation coefficient of olefin/paraffin mixtures was maintained. This suggests that silver species other than the silver ion is active for olefin carrier for facilitated transport. Meanwhile the steady decrease of the separation coefficient was observed in the silver/POZ membranes irradiated under $N_2$. It is suggested that the reduction of silver ions in POZ goes through a different photoreduction mechanism with UV irradiation depending on the environment.t.

• Macromolecular Research
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• 제16권7호
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• pp.626-630
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• 2008

Poly(vinyl pyrrolidone) was used successfully to control the size and distribution of silver nanoparticles generated on inorganic silica nanofibers. The inorganic nanofibers were electro spun using sol-gel chemistry of silicates, and the diameter of the prepared nanofibers was unaffected by adding up to 7% of poly(vinyl pyrrolidone). The silver ions, in the form of silver nitrate, were introduced into the silica nanofibers and reduced to metallic silver by ultraviolet irradiation with a subsequent thermal treatment. The size of the generated silver particles was decreased dramatically by adding poly(vinyl pyrrolidone). The size of the silver nanoparticles was 73 nm when no poly(vinyl pyrrolidone) was added but 23 nm with the addition of only 1% of poly(vinyl pyrrolidone). The extent of reduction could be checked by determining the concentration of silver ions leached into water from the silica nanofibers. After thermal treatment of the silica nanofibers, more than 99% of the silver remained in the nanofibers, indicating almost complete reduction of the silver ions to silver metal.

• 공업화학
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• 제23권1호
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• pp.14-17
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• 2012

다양한 종류의 상온 이온성액체를 이용한 화학적 환원법으로 미세 은 입자를 제조하였다. 이온성액체의 음이온의 종류에 따라 제조된 은 입자는 다양한 크기와 입도분포를 가지는 것이 관찰되었으며, 이는 이온성액체의 음이온이 은 입자들의 결합에 영항을 주기 때문이다. 여러 가지 이온성액체 중에서 미세 은입자를 제조하는데 있어서 가장 효과적인 이온성액체는 1-Butyl-3-methylimidazolium hexafluorophosphate였다.

• 한국분말재료학회지
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• 제24권4호
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• pp.315-320
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• 2017

There has been much interest in recycling electronic wastes in order to mitigate environmental problems and to recover the large amount of constituent metals. Silver recovery from electronic waste is extensively studied because of environmental and economic benefits and the use of silver in fabricating nanodevices. Hydrometallurgical processing is often used for silver recovery because it has the advantages of low cost and ease of control. Research on synthesis recovered silver into nanoparticles is needed for application to transistors and solar cells. In this study, silver is selectively recovered from the by-product of electrodes. Silver precursors are prepared using the dissolution characteristics of the leaching solution. In the liquid reduction process, silver nanoparticles are synthesized under various surfactant conditions and then analyzed. The purity of the recovered silver is 99.24%, and the average particle size of the silver nanoparticles is 68 nm.

• 한국세라믹학회지
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• 제45권4호
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• pp.191-195
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• 2008

Highly ordered silver nanowire with a diameter of 10 nm was arrayed by electroless deposition in a porous anodic aluminum oxide(AAO) membrane. The AAO membrane was fabricated electrochemically in an oxalic acid solution via a two-step anodization process, while growth of the silver nanowire was initiated by using electroless deposition at the long-range-ordered nanochannels of the AAO membrane followed by thermal reduction of a silver nitrate aqueous solution by increasing the temperature up to $350^{\circ}C$ for an hour. An additional electro-chemical procedure was applied after the two-step anodization to control the pore size and channel density of AAO, which enabled us to fabricate highly-ordered silver nanowire on a large scale. Electroless deposition of silver nitrate aqueous solution into the AAO membrane and thermal reduction of silver nanowires was performed by increasing the temperature up to $350^{\circ}C$ for 1 h. The morphologies of silver nanowires arrayed in the AAO membrane were investigated using SEM. The chemical composition and crystalline structure were confirmed by XRD and EDX. The electroless-deposited silver nanowires in AAO revealed a well-crystallized self-ordered array with a width of 10 nm.

• Corrosion Science and Technology
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• 제7권2호
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• pp.130-133
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• 2008

Corrosion of silver by outgassed sulfur species from rubber has been investigated by means of quartz crystal microbalance technique (QCM) and cathodic reduction technique. Silver specimens were placed together with a rubber of predefined quantity in an enclosed environment. Corrosion progressed linearly with time and silver sulfide was found as the corrosion product during all the tests. No significant dependence on RH was observed, while the corrosion rate increased as temperature rose. Furthermore the corrosion rate increased logarithmically with the quantity of the rubber placed in the exposure environment. It may be suggested that the corrosion rate of silver is determined by the amount of outgassed sulfur species which is a function of temperature and the quantity of rubber contained in the exposure environment.

• 대한화학회지
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• 제36권1호
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• pp.24-27
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• 1992

구리나 아연 막대에 의하여 은 졸의 응결이 일어난다. 은 졸의 표면에 있는 은 이온이 구리 혹은 아연 금속과의 산화-환원 반응에 의하여 은 금속으로 환원되면서 응결이 일어난다고 여겨진다. 구리 막대로 응결시킨 은 졸의 라만 스펙트럼을 연구하였다. 은 콜로이드 표면에 붕산과 질산 이온이 흡착되어 있다는 증거를 발견하였다. 은 콜로이드 표면에 흡착된 이들 이온들은 첨가된 흡착제에 의하여 쉽게 치환된다는 사실 또한 발견하였다.

• Bulletin of the Korean Chemical Society
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• 제24권11호
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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.