Photodegradation of Pb-3,4-dihydroxybenzoic acid complex under UV light illumination

2012 ◽  
Vol 65 (5) ◽  
pp. 948-953
Author(s):  
Xuefeng Hu ◽  
Wei Qin
Keyword(s):  
Uv Light ◽  
Light Illumination ◽  
Dihydroxybenzoic Acid ◽  
Solution Ph ◽  
Acid Complex ◽  
Uv Illumination ◽  
Vis Spectroscopy ◽  
Ft Ir ◽  
Ph Conditions ◽  
Total Organic Carbon Analysis

The degradation of 3,4-dihydroxybenzoic acid (3,4-DHBA) in the presence and absence of Pb2+ under UV illumination was studied. Addition of Pb2+ caused the formation of precipitate during photoreaction when the solution pH was higher than 6. The presence of Pb2+ remarkably inhibited the degradation of 3,4-DHBA and its photodegradation intermediates, while complexation of 3,4-DHBA and its photodegradation intermediates with Pb2+ decreased the free Pb2+ in aqueous solutions. Molecular oxygen played an important role in photodegradation of 3,4-DHBA in the presence of Pb2+. UV–Vis spectroscopy was used to investigate the interaction between Pb2+ and 3,4-DHBA at different pH conditions, and FT-IR was used to characterize the precipitate formed during photoreaction. The mineralization of 3,4-DHBA was investigate by total organic carbon analysis.

Synthesis, Photoisomerization and Thermo-Optic Property of Azo Optically Active Polymer

2010 ◽  
Vol 663-665 ◽  
pp. 41-44
Author(s):  
Chang Hong Ge ◽  
Feng Xian Qiu ◽  
Xiao Xian Gu ◽  
Dong Ya Yang
Keyword(s):  
Uv Light ◽  
Inorganic Materials ◽  
Optical Parameters ◽  
Chiral Reagent ◽  
Vis Spectroscopy ◽  
Optic Property ◽  
Order Of Magnitude ◽  
Ft Ir ◽  
Azo Chromophore ◽  
Thermal Volume Expansion

A novel azobenzene optically polymer (P-DA) was synthesized based on the azo chromophore molecule, chiral reagent L(-)-tartaric acid, acryloyl chloride and methacrylate. The P-DA was characterized by FT-IR, UV-Vis spectroscopy, 1H NMR, DSC and TGA. The P-DA had high thermal stability up to its glass-transition temperature (Tg) of 110 oC and 5 % heat weight loss temperature of 199 oC. The UV-induced trans/cis photoisomerization and reflex-isomerization behaviors were investigated. The results indicated that the P-DA solution could undergo photochromism after irradiated by 365 nm UV light. The optical parameters: refractive index (n), the dielectric constant (ε) and thermal volume expansion coefficient (β) of P-DA were obtained. The thermo-optic coefficients are one order of magnitude larger than those of the inorganic materials, such as SiO2 (1.1×10−5 oC -1 and LiNbO3 (4×10−5 oC -1) and was larger than the organic material such as polystyrene (-1.23×10-4 oC -1) and PMMA (-1.20×10-4 oC -1). The conclusion had a little significance to develop optical communication.

Cu/graphene interdigitated electrodes with various copper thicknesses for UV-illumination-enhanced gas sensors at room temperature

2020 ◽  
Vol 22 (44) ◽  
pp. 25769-25779
Author(s):  
Min Zhao ◽  
Attia Falak ◽  
Yi Tian ◽  
Lanqin Yan ◽  
Rujun Liu ◽  
...  
Keyword(s):  
Gas Sensors ◽  
Room Temperature ◽  
High Efficiency ◽  
Uv Light ◽  
Light Illumination ◽  
Interdigitated Electrodes ◽  
Uv Illumination

High efficiency detection of NO2 and NH3 by 8 nm Cu/graphene sensor at room temperature under UV light illumination.

ZnO Tetrapods for Potential Photocatalytic Dye Degradation

2018 ◽  
Vol 779 ◽  
pp. 97-101 ◽  
Author(s):  
Shynggys Sadyk ◽  
Timur Sh. Atabaev
Keyword(s):  
Photocatalytic Activity ◽  
Electron Microscope ◽  
Dye Degradation ◽  
Uv Light ◽  
Photocatalytic Properties ◽  
Light Illumination ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Photocatalytic Dye Degradation ◽  
Scanning Electron

In this study, a facile method was used to prepare ZnO tetrapods for potential dye degradation applications. Field emission scanning electron microscope (FESEM), energy-dispersive X-ray spectroscopy (EDX) and UV-Vis spectroscopy were employed to investigate the morphology, chemical composition, and photocatalytic properties of prepared ZnO tetrapods. A Rhodamine B (RB) dye was used as a model dye to study the photocatalytic activity of the prepared sample. It was shown that RB dye can be efficiently degraded in the presence of ZnO tetrapods under continuous UV-light illumination. Thus, prepared ZnO tetrapods with excellent photocatalytic properties can be potentially used in wastewater treatment.

Nematic Liquid Crystals (NLC) Alignment by the Oriented Nanopatterns of some Polymers Functionalized with Monochlorotriazinyl-β-Cyclodextrin

2012 ◽  
Vol 20 ◽  
pp. 117-128
Author(s):  
Ana Maria Grigoriu ◽  
Constantin Luca ◽  
Aurelia Grigoriu ◽  
Cristina Racu ◽  
Gabriela Hitruc ◽  
...  
Keyword(s):  
Liquid Crystals ◽  
Uv Light ◽  
Nematic Liquid Crystals ◽  
Polarized Light ◽  
Hydroxyl Groups ◽  
Nanostructured Surfaces ◽  
Dichroic Dye ◽  
Vis Spectroscopy ◽  
Linearly Polarized ◽  
Ft Ir

This paper presents the practical strategies of obtaining the oriented nanostructured surfaces of some polymers functionalized with monochlorotriazinyl-β-cyclodextrin (MCT-β-CD) by two techniques: uniaxial rubbing or linearly polarized UV light (LPUVL) irradiation. We have chosen for the present study polymers and copolymers with exotic behavior with hydroxyl groups allowing the grafting of the reactive product monochlorotriazinyl-β-cyclodextrin or whose pyridinic nuclei can be complexated with MCT-β-CD. The obtained oriented nanostructures align colourless nematic liquid crystals (NLC) or NLC coloured with a dichroic dye. The orientation of NLC has been studied by means of polarized light FT-IR spectroscopy (IR dichroism) and polarized light UV-VIS spectroscopy (VIS dichroism). The initial polymers as well as the chemically modified products have an exotic behavior with regard to the ability of orientating the NLC. The polymers functionalized with MCT-β-CD orientate the NLC perpendicularly to the rubbing direction (or, for photopolymers, perpendicularly to the electrical vector of LPUVL).

scholarly journals Photo- and Acid-Degradable Polyacylhydrazone–Doxorubicin Conjugates

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2461
Author(s):  
Maria Psarrou ◽  
Martha Georgia Kothri ◽  
Maria Vamvakaki
Keyword(s):  
Adipic Acid ◽  
Main Chain ◽  
Uv Light ◽  
Attenuated Total Reflection ◽  
Size Exclusion ◽  
Proton Nuclear Magnetic Resonance ◽  
Solution Ph ◽  
Alternating Copolymer ◽  
Vis Spectroscopy ◽  
Self Assembled

Light-mediated polymer degradation has attracted considerable attention in various applications, including photo-patterning, tissue engineering and photo-triggered drug delivery. In this study, we report the synthesis and characterization of a new, linear, main-chain photo- and acid-degradable copolymer based on acylhydrazone linkages. The polymer was synthesized via a step-growth copolymerization of adipic acid dihydrazide with a bifunctional poly(ethylene glycol) bearing benzaldehyde end-groups, under mild acidic conditions, to afford a hydrophilic PEG-alt-adipic acid (PEG-alt-AA) alternating copolymer. The synthesized polymer was characterized by size exclusion chromatography, proton nuclear magnetic resonance and attenuated total reflection-Fourier transform infrared spectroscopies. The main-chain photo- and acid-induced degradation of the copolymer in dimethylsulfoxide and water, respectively, was verified by UV-vis spectroscopy at light intensities as low as 0.1 mW cm−2 at λ = 254 nm. Next, a model anticancer drug, doxorubicin (DOX), was chemically linked to the polymer chain end(s) via acylhydrazone bond(s), resulting in amphiphilic PEG-alt-adipic acid-DOX (PEG-alt-AA-DOX) polymer–drug conjugates. The conjugates were self-assembled in water to form spherical nanoparticles, as evidenced by scanning and transmission electron microscopies. The irradiation of the self-assembled PEG-alt-AA-DOX conjugates with UV light and the decrease of the solution pH resulted in the disruption of the assemblies due to the photolysis and acidolysis of the acylhydrazone bonds, and the release of the therapeutic cargo.

Room-Temperature ZnO Nanoparticle Ethanol Gas Sensors under UV Illumination

2012 ◽  
Vol 486 ◽  
pp. 39-43 ◽  
Author(s):  
S.P. Chang
Keyword(s):  
Gas Sensor ◽  
Gas Sensors ◽  
Spin Coating ◽  
Room Temperature ◽  
Uv Light ◽  
Light Illumination ◽  
Zno Nanoparticle ◽  
Uv Illumination ◽  
Potential Applications ◽  
Nanoparticle Film

A zinc oxide (ZnO) nanoparticle gas sensor was formed by spin coating. We annealed the film at 400, 600, and 800°C for 1 h in air to create a gas sensor. The responses of the gas sensor to ethanol under UV light illumination were investigated. We found that the ZnO nanoparticle film annealed at 800°C had the highest sensitivity. This can be attributed to the fact that the defects of ZnO nanoparticle film annealed at 800°C are considerably more than those for the film annealed at other temperatures. This study demonstrates that ZnO nanoparticles have potential applications as room-temperature ethanol sensors.

Effect of UV Illumination on Deposition of Low-k Si-O-C(-H) Films by PECVD

2004 ◽  
Vol 449-452 ◽  
pp. 473-476 ◽  
Author(s):  
Heon Ju Lee ◽  
Chang Sil Yang ◽  
Chi Kyu Choi
Keyword(s):  
Plasma Parameter ◽  
Uv Light ◽  
Chemical Vapor ◽  
Light Illumination ◽  
Plasma Chemical ◽  
Dielectric Thin Film ◽  
Plasma Chemical Vapor Deposition ◽  
Low Dielectric ◽  
Uv Illumination ◽  
Low K

The characteristics of plasma are important for the deposition of SiOC(-H) low dielectric thin film. The effect of UV light illumination on the plasma parameter in the capacitive coupled plasma chemical vapor deposition (CCP-CVD) system is investigated. The electron density is almost not changed, but the electron temperature decreases by UV light illumination. The deposition rate increases and the dielectric constant of the film is lowered with UV light.

scholarly journals Photocatalytic Properties of Tin Oxide and Antimony-Doped Tin Oxide Nanoparticles

2011 ◽  
Vol 2011 ◽  
pp. 1-15 ◽  
Author(s):  
J. C. M. Brokken-Zijp ◽  
O. L. J. van Asselen ◽  
W. E. Kleinjan ◽  
R. van de Belt ◽  
G. de With
Keyword(s):  
Tin Oxide ◽  
Network Formation ◽  
Uv Light ◽  
Surface Group ◽  
Surface Grafting ◽  
Light Illumination ◽  
Plasmon Band ◽  
Incident Wavelength ◽  
Uv Illumination ◽  
N Doping

For the first time it is shown that N-doped SnO2nanoparticles photocatalyze directly the polymerization of the C=C bonds of (meth)acrylates under visible light illumination. These radical polymerizations also occur when these particles are doped with Sb and when the surfaces of these particles are grafted with methacrylate (MPS) groups. During irradiation with visible or UV light the position and/or intensity of the plasmon band absorption of these nanoparticles are always changed, suggesting that the polymerization starts by the transfer of an electron from the conduction band of the particle to the (meth)acrylate C=C bond. By using illumination wavelengths with a very narrow band width we determined the influence of the incident wavelength of light, the Sb- and N-doping, and the methacrylate (MPS) surface grafting on the quantum efficiencies for the initiating radical formation (Φ) and on the polymer and particle network formation. The results are explained by describing the effects of Sb-doping, N-doping, and/or methacrylate surface grafting on the band gaps, energy level distributions, and surface group reactivities of these nanoparticles. N-doped (MPS grafted) SnO2(Sb ≥ 0%) nanoparticles are new attractive photocatalysts under visible as well as UV illumination.

A new stepped tetranuclear copper(II) complex: synthesis, crystal structure and photoluminescence properties

2017 ◽  
Vol 73 (5) ◽  
pp. 393-398 ◽  
Author(s):  
Elif Gungor
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Uv Light ◽  
Visible Region ◽  
Blue Emission ◽  
Green Emission ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
Vis Spectroscopy ◽  
Ft Ir

Binuclear and tetranuclear copper(II) complexes are of interest because of their structural, magnetic and photoluminescence properties. Of the several important configurations of tetranuclear copper(II) complexes, there are limited reports on the crystal structures and solid-state photoluminescence properties of `stepped' tetranuclear copper(II) complexes. A new CuII complex, namely bis{μ3-3-[(4-methoxy-2-oxidobenzylidene)amino]propanolato}bis{μ2-3-[(4-methoxy-2-oxidobenzylidene)amino]propanolato}tetracopper(II), [Cu4(C11H13NO3)4], has been synthesized and characterized using elemental analysis, FT–IR, solid-state UV–Vis spectroscopy and single-crystal X-ray diffraction. The crystal structure determination shows that the complex is a stepped tetranuclear structure consisting of two dinuclear [Cu2(L)2] units {L is 3-[(4-methoxy-2-oxidobenzylidene)amino]propanolate}. The two terminal CuII atoms are four-coordinated in square-planar environments, while the two central CuII atoms are five-coordinated in square-pyramidal environments. The solid-state photoluminescence properties of both the complex and 3-[(2-hydroxy-4-methoxybenzylidene)amino]propanol (H2 L) have been investigated at room temperature in the visible region. When the complex and H2 L are excited under UV light at 349 nm, the complex displays a strong blue emission at 469 nm and H2 L displays a green emission at 515 nm.

scholarly journals Synthesis and Photocatalytic Properties of ZnWO4Nanocrystals via a Fast Microwave-Assisted Method

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Jing Yan ◽  
Yanhua Shen ◽  
Feng Li ◽  
Taohai Li
Keyword(s):  
Uv Light ◽  
X Ray ◽  
Microwave Assisted ◽  
Uv Illumination ◽  
Uv Light Irradiation ◽  
Transmission Electron ◽  
Photocatalytic Activities ◽  
Highly Effective ◽  
Ft Ir ◽  
Microwave Assisted Method

High crystallinity of ZnWO4nanoparticles has been successfully synthesized via a highly effective and environmentally friendly microwave route by controlling the reaction time and temperature. The products were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), and Fourier infrared spectrum (FT-IR). The crystallinity was enhanced with the increase of the reaction temperature and time. The photocatalytic activities of ZnWO4nanocrystals were evaluated by testing the photodegradation of rhodamine B (RhB) dye under ultraviolet (UV) light irradiation. The results indicated that as-prepared ZnWO4was highly effective for the degradation of RhB. The degradation rate of RhB reached 98.01% after 6 h of UV illumination.

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