• 한국결정성장학회지
• /
• 제31권2호
• /
• pp.69-72
• /
• 2021

The reaction of ammonium ferric sulfate with sodium borohydride in laponite sol yields nanoiron colloidal solution. This solution in air forms transparent yellow brown solution. The resulting solution reacts with bidentate chelating ligands. The reaction products are characterized by UV-Vis absorption spectroscopy and X-ray diffraction. All compounds show metal to ligand charge transfer band in the region of 400~650 nm in UV-Vis absorption spectra. This indicates the formation of iron-ligand complex by air oxidation of nanoiron. Also, XRD patterns exhibit that the iron-ligand complex is intercalated in the interlayer of laponite.

• 대한화학회지
• /
• 제56권6호
• /
• pp.673-678
• /
• 2012

변전위법과 선형분극법을 이용하여 Borate 완충용액에서 철의 부식에 대한 대기의 영향을 조사하였다. 철의 부식은 용액 속에 녹아있는 산소의 양에 크게 영향을 받았다. 용액에 녹아 있는 산소의 환원반응으로 환원전류가 증가하여 부식전위가 양의 방향으로 이동하였다. 물 또는 산소의 환원 반응에 의하여 생성된 $OH^-$ 이온은 철 전극의 전기이중층에 $OH^-$ 이온의 농도를 증가시켜 철 전극에 $OH^-$ 이온의 흡착을 용이하게 하였다. 철 전극 표면에 $OH^-$ 이온의 흡착은 Langmuir isotherm 또는 Temkin logarithmic isotherm을 이용하여 설명할 수 있었다.

• 한국의류산업학회지
• /
• 제26권4호
• /
• pp.411-423
• /
• 2024

This study examined the dyeability and functionality of silk fabrics dyed using shiitake mushroom pins discarded in large quantities on mushroom farms. FT-IR and UV-Vis spectral analyses showed that polyphenols and flavonoids were present in the hot-water extract of shiitake mushroom pins. Optimal dyeing conditions for silk fabrics were a dye concentration of 50% (v/v), dyeing temperature of 80℃, dyeing time of 60 minutes, and dyebath pH of 5.3. The post-mordant method showed a greater effect on the increase in dye uptake and color change than the pre-mordant method. Unmordanted fabrics appeared as a YR Munsell color. Except for the Cu-mordant, all post-mordanted fabrics produced a Y Munsell color. The FE-SEM/EDX analysis confirmed that the natural iron solution and mud contained various metal ions. The Fe component was found to have the greatest effect on the dye uptake and color properties. The colorfastness of the unmordanted fabrics to washing, dry cleaning, rubbing, and perspiration was excellent (above grade 4), whereas light was grade 3-4. In the case of post-mordanted fabrics with a natural iron solution, the colorfastness to washing, wet rubbing, and light improved by 0.5 grades. For post-mordanted fabrics with mud, the colorfastness to light and sweat improved by 0.5 grades. The bacterial reduction rate for staphylococcus aureus in fabrics dyed with shiitake mushroom pin extract was excellent at over 99.9%, the bacterial reduction rate for klebsiella pneumoniae was 98.1%, and the deodorization rate was excellent at 90%. These results indicate that shiitake mushroom pins can be used as a sustainable, functional natural dye.

• 대한화학회지
• /
• 제46권5호
• /
• pp.444-456
• /
• 2002

차체의 산화를 방지하기 위하여 희생적 양극을 사용한 산화방지 장치를 개발하였다. 희생적 양극은 철보다 산화 전위가 높은 Mg, Al, Zn으로 만들어 졌고 이것은 차체의 철이나 철합금보다 먼저 산화되어 차체의 부식을 방지한다. 차체 산화방지 장치를 제작하여 철시편을 염산, 질산 및 황산에 대한 방식효과를 시간에 따라 측정하였고 SEM과 XPS를 이용하여 철시편 표면의 방식효과를 분석하였다. 철시편을 산화 방지 장치에 연결하면 산화되어 산성용액 속으로 녹아 들어가는 철의 양이 현저하게 감소하고 철시편 표면의 산화가 방지되며 산화된 철은 $Fe_2O_3$의 산화형태를 가짐을 확인하였다. 따라서 차체 산화방지를 차체에 직접 부착한다면 차체의 부식 및 산화를 효과적으로 방지할 것으로 기대된다.

• 대한화학회지
• /
• 제19권2호
• /
• pp.142-146
• /
• 1975

황산제일철을 원료로 해서 함수산화철 안료를 제조하기 위한 실험이다. 황산제일철을 암모니아로 중화해서 Mohr's salt(ferrous ammonium sulfate)을 만들고 Mohr's salt의 농도를 Fe(II) 이온농도, 14${\sim}$72g/l, 수소이온농도를 pH3 또는 6으로 조절한뒤, 반응온도는 $90{\sim}100^{\circ}C$로 일정하게 유지하고 반응시간 2시간, 3기압으로 공기 가압한 결과는 다음과 같다. Mohr's salt의 농도가 진하고, 중성으로 갈수록 함수산화철의 수득율이 증가되며, Mohr's salt 농도가 Fe(II) 이온농도, 42.81g/l 일때, 91.5% 이상의 수득율을 얻었다. 이렇게하여 생성된 함수산화철의 결정형은 $\alpha$-goethite형이며, 색상도 천연 ${\alpha}$-goethite와 유사하였다. 이것을 $500^{\circ}C$로 하소(calcination)하니 미려한 적갈색을 띤 ${\alpha}-Fe_2O_3$가 생성되었다.

• 대한화학회지
• /
• 제51권1호
• /
• pp.14-20
• /
• 2007

금(Au) 전극 위에 전해 석출한 철족 원소(Fe, Co, Ni)를 전극으로 phthalate 완충 용액에서 철족 원소의 부식과정을 조사하였다. Phthalate 완충용액의 pH의 변화에 대한 부식전위와 부식전류를 측정하여 각 원소(Fe, Co, Ni)전극의 산화반응과 환원반응에 대한 Tafel 기울기를 구하였으며 Tafel 기울기를 포함한 정량적인 전기화학 인자를 측정하여 전극의 산화반응과 환원반응에 대한 반응 메커니즘을 제안하였다. Phthalate 완충 용액에 존재하는 화학 종의 흡착은 철족 원소 전극의 산화반응에 영향을 미치는 것으로 보인다.

• 대한화학회지
• /
• 제56권5호
• /
• pp.542-547
• /
• 2012

Borate 완충용액에서 Fe의 산화 반응 경로와 생성된 산화피막의 전기적 특성을 조사하였다. Fe는 pH에 의존하는 두 가지의 반응 경로에 의하여 산화되었으며 산화된 피막은 Mott-Schottky 식이 적용되는 n-형 반도체 성질을 가지고 있음을 알 수 있었다.

• 대한미생물학회지
• /
• 제34권5호
• /
• pp.461-470
• /
• 1999

Growth under conditions of iron-restriction and the production of siderophore was examined in Vibrio mimicus ATCC 33653. This strain grew and multiplied in the presence of the high-affinity iron chelators ethylenediamine-di (o-hydroxyphenylacetic acid). Chrome azurol S (CAS) agar and solution were used to detect the production of siderophore under these condition. Siderophore could be detected in the iron-restricted culture supernatants. The siderophore was extracted from iron-restricted culture supernatants by phenol-chloroform-ether method and purified by Dowex ion-exchange and Sephadex G-25 gel filtracton chromatography. The purified siderophore was confirmed by paper chromatography and HPLC. The Purified siderophore enhanced the growth of V. mimicus when the bacterium was grown in iron limited medium. Injection of both the siderohore and the bacteria to mice resulted in more rapid death than that of the only bacteria. However, the siderophore did not show lethality to mice and any toxicity to cell line like HeLa and U937.

• Bulletin of the Korean Chemical Society
• /
• 제27권4호
• /
• pp.489-494
• /
• 2006

Goethite, hematite, magnetite and synthesized iron oxide are used as catalysts for Fenton-type oxidation of phenol. The synthesized iron oxides were characterized by X-ray diffraction (XRD), BET, X-ray photoelectron spectroscopy (XPS), and electron paramagnetic resonance (EPR). The catalytic activity of these materials is classified according to the observed rate of phenol oxidation. The effectiveness of the catalysts followed the sequence: ferrous ion > synthesized iron oxide >> magnetite hematite > goethite. According to these results, the most effective iron oxide catalyst had the structure similar to natural hematite. The surface oxidation state of the catalyst was between magnetite and hematite (+2.5 ~ +3.0). Phenol degraded completely in 40 min at neutral pH (pH = 7). Soluble ferric and ferrous ions were not detected in the filtrate from Fenton reaction solution by AAS. The formation of hydroxyl radicals was confirmed by EPR.

• 한국염색가공학회지
• /
• 제11권4호
• /
• pp.39-49
• /
• 1999

In order to study the properties of cochineal colors, uv-visible spectra of cochineal colors solution, dyeing properties on the wool in several dyeing conditions and thermodynamic parameters were investigated. UV-visible spectra of cochineal colors solution showed hypochromic effect with the lapse of irradiation time but bathochromic shift with decreasing acidity of solution and addition of metallic ions. The concentration of cochineal colors in wool fiber increased with the increase of dyeing temperature, time, and acidity of initial dyebath. The value of apparent diffusion coefficients and standard affinities of dyeing decreased with the increase of dyeing temperature. The standard heats of dyeing$(\Delta{H}^\circ)$ and variation of entropy$(\Delta{S}^\circ)$ increased with the increase of concentration of initial dyebath. The activation energy$(E_a)$ were calculated to be 1.399~2.595kcal/mol in condition of 6~1%(o.w.f) dyebath. Wool fabrics were dyed reddish blue by iron sulfate, copper sulfate, aluminum acetate and tannic acid, and red by tin chloride, respectively. Lightfastness of wool fabrics dyed by cochineal colors were increased by mordant treatment, especially copper sulfate and iron sulfate treatment.