Toward efficient broad-spectrum UV absorption of carbon dots: Facile preparation, performance characterization and its application as UV absorbers

Jiemin Qiu,Weihao Ye,Congcong Chen,Zhiqiang Xu,Chaofan Hu,Jianle Zhuang,Hanwu Dong,Bingfu Lei,Guangqi Hu,Yingliang Liu 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.117 No.-

UV absorbers are sustainable substances that inhibit the ultraviolet (UV) radiative degradation of polymers. In previous reports, the as-prepared carbon dots (CDs) possess only an absorption band at UVA(320–400 nm). To achieve broad-spectrum UV absorption (200–400 nm), increasing the concentrationof the CDs solution becomes common. However, a high concentration solution seriously affects the lighttransmittance due to its heavy yellow color. Furthermore, the promising organic UV absorbers cannotachieve broad-spectrum UV absorption. In this work, we initially synthesized three-component watersolublecarbon dots (OP–CDs), which delivers an excellent UV absorption (98 % UVA and 100 % UVB atthe concentration of 1.7 102 mg/mL; 99 % transmittance in visible light). Moreover, OP–CDs exhibitoutstanding stability at high temperatures and different pH. With the corporation of OP–CDs and polyvinylalcohol (PVA), a high-performance UV-shielding film was formed, leading to enhanced broadspectrumUV shielding performance and improved mechanical properties, resistance of photocatalyticactivity and anti-UV aging ability compared with pure PVA film. Notably, the PVA film remains hightransparency with the addition of OP–CDs. The study suggests that the corporation of OP–CDs and polymersis effective in anti-UV degradation.

Synthesis of fullerene[C60]-silver nanoparticles using various non-ionic surfactants under microwave irradiation

Jeong Ho Lee,Byoung Eun Park,Young Min Lee,Sung Ho Hwang 한국물리학회 2009 Current Applied Physics Vol.9 No.2

Silver nanoparticles were synthesized from the reaction of silver nitrate (AgNO3) with a 1 wt% aqueous solution of polysorbate 20, polysorbate 40, polysorbate 60, polysorbate 80, and Brij 97, respectively, under microwave irradiation. The resulting nanoparticles were effectively dispersed throughout water and characterized by UV–vis spectra and transmission electron microscopy (TEM). The reaction time of 45 s was investigated by monitoring the color change of the nanoparticle solution. The peaks in the UV–vis spectra showed surface plasmon resonance characteristics inherent in silver nanoparticles. The nanoparticles were reacted with 4-aminothiophenol in water, followed by addition of diethyl ether and fullerene[C60] in toluene and stirring for 24 h. The resulting fullerene[C60]-silver nanoparticles were characterized by UV–vis and MALDI–TOF–MS spectra. Silver nanoparticles were synthesized from the reaction of silver nitrate (AgNO3) with a 1 wt% aqueous solution of polysorbate 20, polysorbate 40, polysorbate 60, polysorbate 80, and Brij 97, respectively, under microwave irradiation. The resulting nanoparticles were effectively dispersed throughout water and characterized by UV–vis spectra and transmission electron microscopy (TEM). The reaction time of 45 s was investigated by monitoring the color change of the nanoparticle solution. The peaks in the UV–vis spectra showed surface plasmon resonance characteristics inherent in silver nanoparticles. The nanoparticles were reacted with 4-aminothiophenol in water, followed by addition of diethyl ether and fullerene[C60] in toluene and stirring for 24 h. The resulting fullerene[C60]-silver nanoparticles were characterized by UV–vis and MALDI–TOF–MS spectra.

금 나노입자의 크기에 따른 광학적 특성변화

입팔 유샤프,이일수,배홍섭,김정수,장준혁,권문호,홍성욱 한국물리학회 2014 새물리 Vol.64 No.3

Three different-sized gold nanoparticles were synthesized to investigate the size dependence of the optical absorbance in aqueous solutions of nanoparticles. The particles were spherical in shape on the TEM images and had average diameters of 14.49 ± 1.12 nm, 16.11 ± 1.32 nm, 24.77 ± 1.76 nm, respectively. The resonance wavelength of the surface plasma was red-shifted in the UV-VIS spectra with increasing diameter of the particles. The spectra also showed that the optical absorbance increased as the particle size increased, which is as expected. Also, the concentration dependence of the absorbance showed that the absorbance increased with increasing particles size. 금 나노입자 수용액에서 광학적 특성이 입자의 크기에 따라 어떻게 변하는지를 관찰하기 위해 크기가 다른 금 나노입자를 형성하였다. TEM (투과전자현미경)으로 관찰한 금 나노입자의 모양은 구형이고 그 직경은 각각 14.49 ± 1.12 nm, 16.11 ± 1.32 nm, 24.77± 1.76 nm이었다. UV-VIS(적외선-가시광선) 스펙트럼에서 표면 플라즈마 공명의 파장은 입자의 크기가 증가함에 따라 적색편이 됨이 관찰되었다. 또한 흡수력 (absorbance)도 입자의 크기가 증가함에 따라 증가함이 관찰되었다. 나노입자의 농도에 따른 흡수력의 변화를 관찰하기 위해 여러 농도의 나노입자 수용액을 만들었다. UV-VIS 스펙트럼을 통해 농도가 커짐에 따라 흡수력의 피크는 증가함이 관찰되었고, 이 피크의 증가는 입자의 크기에 비례함을 볼 수 있었다.

Photohysical Properties of New Psoralen Derivatives:Psoralens Linked to Adenine through Polymethylene Chains

Yoo, Dong-Jin,Park, Hyung-Du,Kim, Ae-Rhan,Rho, Young S.,Shim, Sang-Chul Korean Chemical Society 2002 Bulletin of the Korean Chemical Society Vol.23 No.9

The model compounds, 8-methoxypsoralen-CH2O(CH2)n-adenine (MOPCH2OCnAd, n=2, 3, 5, 6, 8, and 10) in which 5 position of 8-methoxypsoralen (8-MOP) is linked by various lengths of polymethylene bridge to N9 of adenine. UV absorption spectra are identical with the sum of MOPCH2OC3 and adenine absorption spectra. Solvent effects on the UV absorption and fluorescence emission spectra indicate that the lowest excited singlet state is the $(\pi${\rightarrow}$\pi*)$ state. The spectral characteristics of the fluorescence of MOPCH2OCnAd are strongly dependent upon the nature of the solvents. The fluorescence emission spectra in aprotic solvents are broad and structureless due to the excimer formation through the folded conformation accelerated by hydrophobic ${\pi}-{\pi}$ stacking interaction. Increasing polarity of the protic solvents leads to higher population of unfolded conformation stabilized through favorable solvation and H-bonding, and consequently to an increase in the fluorescence intensity, fluorescence lifetime, and a shift of fluorescence maximum to longer wavelengths. The decay characteristics of the fluorescence in polar protic solvents shows two exponential decays with the lifetimes of 0.6-0.8 and 1.6-1.9 ns in 5% ethanol/water, while MOPCH2OC3 shows 0.5 and 1.7 ns fluorescence lifetimes. The long-lived component of fluorescence can be attributed to the relaxed species (i.e., the species for which the solvent reorientation (or relaxation) has occurred), while the short-lived components can be associated with the unrelaxed, or only partially relaxed, species.

Effectiveness of full spectrum light soaking on solar cell degradation analysis

박상현,SeJin Ahn,곽지혜,Keeshik Shin,Seoung Kyu Ahn,Kyung Hoon Yoon,Yunae Cho,김동욱,Jae Ho Yun 한국물리학회 2013 Current Applied Physics Vol.13 No.8

This study examined the effect of UV-spectrum light soaking on solar cell degradation tests. An indoor light soaking test was evaluated over three different spectral ranges: “UV only”, “UV blocked” and “Full spectrum”. a-Si:H and poly-crystalline silicon solar cell technologies were studied by light soaking tests with the same optical filter configurations. The IeV measurement results demonstrated that “UV only” irradiated solar cells exhibited the smallest output power degradation, which was only half of a percent variation compared with the full spectrum light soaking case. Using a filter that excluded the effect of the UV spectral range on light soaking, the “UV blocked” case also exhibited a significant output power degradation of the solar cells. A comparative analysis of the solar cell response, based on the IeV characteristics and the diode ideality factor under these different light soaking spectra, demonstrated the importance of the full spectrum light soaking test in the evaluation of the long-term performance of solar cells.

Synthesis of fullerene[C60]-gold nanoparticles using non-ionic surfactants polysorbate 80 and brij 97

고원배,Byoung Eun Park,Young Min Lee,황성호 한양대학교 세라믹연구소 2009 Journal of Ceramic Processing Research Vol.10 No.1

The synthesis of gold nanoparticles was investigated with non-ionic surfactants such as polysorbate 80, brij 97 and KAuCl4 in water. The products of gold nanoparticle were well dispersed in water and investigated by UV-vis spectra and TEM. The reaction time for the synthesis of gold nanoparticles was investigated by monitoring the change of color and the change of the peak of the UV-vis spectra in the absence of ultrasonic irradiation and in the presence of ultrasonic irradiation. Gold nanoparticles reacted with 4-aminothiophenol in water and then, diethylether was added, and fullerene[C60] in toluene which was stirred for 24 h. The fullerene[C60]-gold nanoparticles were characterized by UV-vis and MALD-TOF-MS spectra.

UV-Vis Spectra of N,N`-Bis (4`-Aminophenyl)-1,4-quinonenediimine Doped with H₄SiW₁₂O₄₀

Jian Gong,Xiu Jun Cui,Ya Guang Chen,Zhong Wei Xie,Lun Yu Qu 한국고분자학회 2004 Macromolecular Research Vol.12 No.1

Lamp형 UV/O3 발생기의 특성과 활용에 관한 연구

송현직 한국지식정보기술학회 2021 한국지식정보기술학회 논문지 Vol.16 No.5

In this paper, a lamp type UV/O3 generator has been designed and manufactured, which can carry out a role of ozonizer and light source by using photo chemical reaction methods. The discharge, spectrum, illuminance and ozone characteristics of a lamp type UV/O3 generator have been studied. The important conclusions obtained from this paper can be summarized as follows. Spectrum characteristics for generator, ultraviolet ray of a short wavelengths and a visible ray are radiated. The illuminance of a generator was found to be useful for “color distinctive work in the dark spaces” and “the useful spaces in the dark atmosphere sometimes” in accordance with KS A 3011 and KS A 7612. The ozone concentration is inversely proportional to quality of supplied oxygen gas but proportional to operating number of generator. The ozone generation is proportional to ozone concentration. The ozone yield is proportional to quality of supplied oxygen gas but inversely proportional to operating number of generator. As a result, the maximun ozone concentration, generation and yield can be obtained 1,624[ppm], 155.8[mg/h] and 11.2[g/kwh] respectively. According to the ozone generation and ultraviolet ray radiation characteristics, the lamp type UV/O3 generator and apply to an improvement environment for inner room and light source.

Spectroscopic Studies on the Oxidation of Catechin in Aqueous Solution

Bark, Ki-Min,Yeom, Ji-Eun,Yang, Jeong-Im,Yang, Ik-Jun,Park, Chul-Ho,Park, Hyoung-Ryun Korean Chemical Society 2011 Bulletin of the Korean Chemical Society Vol.32 No.9

The spectroscopic behavior of catechin (5,7,3',4'-tetrahydroxyflavan-3-ol), has been studied in the presence and the absence of air using UV-vis absorption spectrophotometry and fluorescence spectroscopy. The UV-vis absorption spectrum of catechin shows a very sharp and strong absorption maximum peak at 275 nm in deaerated water. New absorption maximum peaks appeared in aerated water, as well as in basic aqueous solution, caused by the oxidation of catechin. The absorbances in the UV-vis absorption spectrum of catechin decreased when the solution was left in the dark for a long time. The fluorescence emission spectrum of catechin after a long time period differs markedly from that in freshly prepared solution; the fluorescence maxia shifted as time passes after adding catechin to the solutions. When the deaerated basic catechin solutions were left in the dark for a long time, their fluorescence quantum yields were found to be nearly zero. This suggests that the oxidized catechin molecules were seen to have slowly undergone successive chemical reactions in basic buffer solution.

Spectroscopic Studies on the Oxidation of Catechin in Aqueous Solution

박기민,Chul-Ho Park,Ik-Jun Yang,Jeong-Im Yang,Ji-Eun Yeom,박형련 대한화학회 2011 Bulletin of the Korean Chemical Society Vol.32 No.9

The spectroscopic behavior of catechin (5,7,3',4'-tetrahydroxyflavan-3-ol), has been studied in the presence and the absence of air using UV-vis absorption spectrophotometry and fluorescence spectroscopy. The UV-vis absorption spectrum of catechin shows a very sharp and strong absorption maximum peak at 275 nm in deaerated water. New absorption maximum peaks appeared in aerated water, as well as in basic aqueous solution, caused by the oxidation of catechin. The absorbances in the UV-vis absorption spectrum of catechin decreased when the solution was left in the dark for a long time. The fluorescence emission spectrum of catechin after a long time period differs markedly from that in freshly prepared solution; the fluorescence maxia shifted as time passes after adding catechin to the solutions. When the deaerated basic catechin solutions were left in the dark for a long time, their fluorescence quantum yields were found to be nearly zero. This suggests that the oxidized catechin molecules were seen to have slowly undergone successive chemical reactions in basic buffer solution.