• 한국염색가공학회지
• /
• 제26권1호
• /
• pp.53-62
• /
• 2014

This study examined the dyeability, color fastness and functionality of cotton fabrics dyed with residual parts of cultivated Pteridium aquilinum. UV-Vis absorption spectrum, TLC and FT-IR spectra analysis showed that colorants of Pteridium aquilinum are a mixture of pyrogallol tannin and catechol tannin. Optimum dyeing conditions was confirmed colorant concentration of 500% at $100^{\circ}C$ for 60 minutes. Color fastness followed to washing, rubbing, perspiration and light as 4-5, 5, 4-5(acidic), 3-4(alkaline) and 2, respectively. Deodorization rates of ammonia($NH_3$) and acetic acid ($CH_3COOH$) were analyzed 88.8% and 78.0%. UV protection rate was 94.2% of UV-A and 96.8% of UV-B. UV protection factor(UPF) was 27. Therefore residual parts of cultivated Pteridium aquilinum could be used for a new functional colorant.

• 한국광물학회지
• /
• 제22권4호
• /
• pp.385-393
• /
• 2009

마다가스카르 산 투어말린의 보석광물학적 특징들을 알기 위해 물리적 특성, 원소분석, 내포물 분석, 그리고 분광분석(UV-VIS 분광기, FTIR 분광기)을 하여 다른 산지와 비교 연구하였다. 물리적 특성은 다른 산지의 것과 큰 차이를 보이지 않았다. 자외선-가시광선 분광분석 결과 녹색과 청색의 시료는 Fe 성분이 많아 $Fe^{3+}$에 의한 714~743 nm 영역에서 높은 흡수 밴드가 나타났고 분홍색은 $Mn^{3+}$에 의해 510~530 nm에서 높은 흡수를 보였다. 갈색 시편은 Mn이 많아 $Mn^{2+}-Ti^{4+}$ 전하전이에 의해서 325 nm의 자외선 영역에서 나타난 높은 흡수에 기인하였다. 또한 무색 시편에서는 $Mn^{2+}$에 의한 406~413 nm 사이의 밴드가 매우 미약하거나 Mn의 양이 적어 $Mn^{2+}$의 영향이 거의 없어 발색이 되지 않았다고 본다. 적외선 분광분석에서는 4300~4500 $cm^{-1}$ 영역에서 금속-OH의 스트레칭과 밴딩이 조합된 모드에 의한 여러 개의 흡수 밴드가 나타났다. 내포물에서는 평행한 관상 속에 적철석이 녹아있는 형태가 나타났다. 연구 결과 마다가스카르 산의 투어말린은 Cu는 검출되지 않았으나 Fe과 Mn이 모두 검출되었고 이들의 양에 따라 다양한 색상이 나타남을 확인할 수 있었고 물리적 특성과 적외선 영역의 흡수 밴드, 그리고 내포물들은 다른 산지와 큰 차이를 보이지 않았음을 확인할 수 있었다.

• 대한환경공학회지
• /
• 제29권9호
• /
• pp.989-996
• /
• 2007

본 연구에서는 망간산화물 존재 하에서의 1-naphthol(1-NP)의 산화-결합반응을 통한 변환반응과 반응산물을 조사하였다. 변환 반응에 의해 생성된 반응산물을 대상으로 한 용매 추출과 HPLC, GC/MS, LC/MS 및 UV-Vis. 흡광특성 분석 등을 통해 반응산물의 분자 구조특성을 규명하였다. 반응 상등액에서 검출된 반응산물은 모두 1-NP에 비하여 높은 극성을 보였다. 주요 반응산물로는 1,4-naphthoquinon(1,4-NPQ)와 dimer, trimer 등의 소 중합체(oligomers)를 포함하며 특히, 용매추출$(CH_2Cl_2)$ 후 수용액에 잔류하는 친수성 형태의 반응산물은 다양한 분자량의(m/z=$400\sim2000$) 중합체로서 토양 휴믹물질(풀빅산)과 유사한 형태의 UV-Vis 흡광특성을 보였다. 또한, 비 반응성 생성물인 1,4-NPQ는 1-NP 존재 하에서 망간산화물에 의한 교차-결합(cross-coupling)을 통해 중합체로 변환될 수 있음을 확인하였다. 본 실험조건(20.5 mg/L, 1-NP, 2.5 g/L $MnO_2$, pH 5)에서 산화-결합 반응에 의한 중합체 형성으로 제거되는 1-NP의 양(mg/L)은 초기농도 대비 약 83%에 해당하며, 이들 중 약 30% 정도는 침전층에서 중류수와 메탄올$(CH_3OH)$에 의해 추출되지 않는 안정화된 형태의 불용성 중합체 생성물로 존재하였다. 이상의 결과는 망간산화물에 의한 산화-결합반응이 naphthol 오염토양의 처리에 있어서 소 중합체와 중합체 침전물로의 변환을 통한 오염 저감 및 제거 효과를 나타냄을 제시한다.

• Bulletin of the Korean Chemical Society
• /
• 제30권9호
• /
• pp.1973-1977
• /
• 2009

In the present study, at first, 2,4-Dihydroxy Salophen (2,4-DHS), has been synthesized by combination of 1, 2-diaminobenzene and 2,4-dihydroxybenzaldehyde in a solvent system. This ligand containing meta-quinone functional groups were characterized using UV-Vis and IR spectroscopies. Subsequently, the interaction between native calf thymus deoxyribonucleic acid (ct-DNA) and 2,4-DHS, was investigated in 10 mM Tris/HCl buffer solution, pH 7.2, using UV-visible absorption and fluorescence spectroscopies, thermal denaturation technique and viscosity measurements. From spectrophotometric titration experiments, the binding constant of 2,4-DHS with ct-DNA was found to be (1.1 ${\pm}\;0.2)\;{\times}\;10^4\;M^{-1}.$ The fluorescence study represents the quenching effect of 2,4-DHS on bound ethidium bromide to DNA. The quenching process obeys linear Stern-Volmer equation in extended range of 2,4-DHS concentration. Thermal denaturation experiments represent the increasing of melting temperature of DNA (about 3.5 ${^{\circ}C}$) due to binding of 2,4-DHS. These results are consistent with a binding mode dominated by interactions with the groove of ct-DNA.

• 한국입자에어로졸학회지
• /
• 제6권1호
• /
• pp.29-35
• /
• 2010

Transition metals such as V, Fe, and Ni were used to synthesize doped zinc oxide nanoparticles from mixed liquid precursors by using the flame spray pyrolysis (FSP). The effects of dopants on the powder properties such as morphology, specific surface area, crystal structure, and light adsorption were analyzed by TEM, BET, XRD, and UV-Vis diffuse reflection spectrum (DRS), respectively. The results showed that hexagonal wurtzite structured ZnO:M (M = V, Fe, Ni) nanoparticles were successfully synthesized by the FSP. The transition metal-doping resulted in the decrease in its particle size and crystallite size. The UV-vis absorption spectra of ZnO:M nanoparticles were also red-shifted. ZnO:V showed the highest MB degradation of 99.4% under the UV irradiation after 3 hrs.

• 한국전기전자재료학회논문지
• /
• 제21권11호
• /
• pp.1010-1018
• /
• 2008

In this report, we describe the use of gold nanoparticles (AuNPs) immobilized on pH. responsive, cross-linked poly(4-vinylpyridine) (P4VP) thin films, as a potential application for pH nanosensors. The methodology is based on the variation in surface plasmon resonance of immobilized AuNPs with changing the interparticle distances, caused by the swelling/deswelling of the pH responsive P4VP polymer films. The change in optical properties of the immobilized AuNPs in response to the pH of surrounding media was investigated by a simple yet powerful tool; UV-vis absorption spectroscopy. The swelling of the P4VP chains at pH 2 causes an increase in the interparticle distances of immobilized AUNPS ($\sim20nm$) and hence leads to a blue shift of 48 nm in their surface plasmon resonance band peak. On the other hand, when the surrounding media was altered from pH 2 to 10, a red shift of absorption maxima was observed. The changes were rapid, and the effect was reversible. This system could prove to be useful in fabricating nanosensors for detecting the pH or pH changes of surrounding aqueous medium.

• Journal of the Korean Physical Society
• /
• 제73권11호
• /
• pp.1729-1734
• /
• 2018

Organic-inorganic halide perovskite single crystals undergo phase transition of being cubic, tetragonal, or orthorhombic depending on the temperature. We investigated the $CH_3NH_3PbBr_{3-x}I_x$ single crystals grown by the inverse temperature crystallization method with temperature-dependent UV-Vis absorption and photoluminescence. From the temperature-dependent absorption measurement, the optical band gap is extracted by derivation of absorption spectrum fitting and Tauc plot. In our results, $CH_3NH_3PbBr_{3-x}I_x$ single crystals show that an abrupt change in optical band gap, PL peak position and intensity appears around 120 K - 170 K regions, indicating the phase transition temperature.

• Carbon letters
• /
• 제10권1호
• /
• pp.14-18
• /
• 2009

We measured the degree of macrodispersion of the various single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs) using UV-VIS-NIR absorption spectroscopy. CNTs were dispersed with SDS of 2 wt % in deionized water using the homogenizer and then were further centrifugated at 6000 g for 10 min. The degree of macrodispersion, expressed by $D_m({\lambda})=A_a({\lambda})/A_b({\lambda})^*100$ (%), where ${\lambda}$ is the wavelength and $A_a({\lambda})$ and $A_b({\lambda})$ are the absorbance of the sample after and before centrifugation, respectively. In the case of MWCNTs, we evaluated the degree of macrodispersion by the average degree of macrodispersion ($D_m({\lambda})$) between 1000 and 1200 nm. The degree of macrodispersion of SWCNTs was evaluated at the wavelength in which van Hove singularity-related transition regions were excluded, i.e., the range was chosen between ${E_{11}}^S$ and ${E_{22}}^S$ peaks. We have estimated six samples with the same method. The standard deviation of each sample was lower than 5. Therefore, we presented a reliable evaluation method for the macrodispersion of CNTs for standardization.

• 한국세라믹학회지
• /
• 제40권9호
• /
• pp.902-908
• /
• 2003

Au/TiO$_2$ core-shell 구조 나노 미립자가 졸-겔법에 의해서 제조되었고, TiO$_2$ shell의 형상과 결정성이 TEM과 UV-Vis. absorption spectrometer에 의해서 조사되었다. Au/TiO$_2$ core-shell 나노 미립자는 Au 콜로이드 에탄올 수용액 중에서 TOAA(Titanium Oxide Acethylacetonate)의 가수분해에 의해 합성될 수 있었다. Au 나노 미립자의 표면에 형성된 TiO$_2$ shell의 두께는 약 1 nm이었다. TiO$_2$ shell의 결정성을 조사하기 위하여. TiO$_2$가 피복된 Au 콜로이드 에탄올 용액에 254 nm의 자외선과 $^{60}$Co의 방사선을 조사하였다. Au 나노 미립자의 surface plasmon 현상은 방사선이 조사되었을 때만 나타났고, 이 결과로부터 TiO$_2$ shell은 비정질 상태임을 알 수 있었으며, Au의 분산성 향상을 위해 표면에 처리된 MUA(Mercaptoundecanoic Acid)층은 전자의 이동을 방해하는 장애물로 작용하지 않음을 확인할 수 있었다.

• 한국염색가공학회지
• /
• 제27권4호
• /
• pp.340-344
• /
• 2015

The interaction between curcumin(1,7-bis[4-hydroxy-3-methoxyphenyl]-1,6-heptadiene-3,5-dione) and ethylamines was studied in DMSO:$H_2O$(5:1, v/v) using absorption and fluorescence measurements. The association constant, $K_{ass}$, and the Stern-Volmer constants were calculated by the Benesi-Hildebrand and Stern-Volmer equation, respectively. Curcumin displayed marked UV-Vis absorption changes and highly responsive fluorescence quenching in the presence of ethylamine and the quenching ability was enhanced almost linearly with the concentration of ethylamines. The apparent Stern-Volmer constant measured for the ethylamine-curcumin system was about 1000-fold greater than that of the triethylamine-curcumin system, indicating considerably greater quenching efficiency of ethylamines.