Photo Characterization of Spirooxazine and Naphthopyran Organic Dyes upon UV Irradiation

2014 ◽  
Vol 879 ◽  
pp. 96-101
Author(s):  
Noor Zalikha Islam Mohamed ◽  
M.Z.A. Malik ◽  
S.A.A.A. Nazri ◽  
M.T. Zainuddin ◽  
N.M.A. Aziz ◽  
...  
Keyword(s):  
Oxygen Atom ◽  
Organic Dyes ◽  
Uv Light ◽  
Irradiation Time ◽  
Ethanol Solution ◽  
Protic Solvent ◽  
Multiple Exposure ◽  
Photochromic Transformation ◽  
Color Changes

Organic dyes namely 1,3,3-trimethylindolino-naphtospirooxazine (TINS) and 3,3-diphenyl-3H-napthol [2,1-pyran DNP) were used in studies of photochromic transformation in ethanol solution. The samples were exposed to UV light ranging from 5, 10 and 15s respectively. TINS absorbs UV light at 613nm for multiple exposure time. The absorption initiated the opening of oxazine spirostructure with formation of open merocyanine species. Irradiation of DNP with UV at 5, 10 and 15s absorbs at 413nm with formation of opening cyclicstucture of naphthopyran, namely allenyl-naphtol. The intensity peaks of TINS and DNP were increased with increasing the period of irradiation time. TINS and DNP dyes exhibit normal photochromic in the polar protic solvent by displaying color changes form transparent to color blue and light orange under exposed UV light. The photochromic activity of these compounds is due to the reversible light-induced cleavage of the C-O bond between the heterocyclic oxygen atom and the quaternary carbon.

Magnetic field assisted photocatalytic degradation of organic dyes in the presence of Ag/TiO2 coated composite

2013 ◽  
Vol 67 (4) ◽  
pp. 722-728 ◽  
Author(s):  
Jian Wang ◽  
Jingqun Gao ◽  
Jun Wang ◽  
Yu Zhai ◽  
Zhongxing Wang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Photocatalytic Activity ◽  
Photocatalytic Degradation ◽  
Rotational Speed ◽  
Organic Dyes ◽  
Dye Degradation ◽  
Uv Light ◽  
Irradiation Time ◽  
Sol Gel ◽  
Heat Treated

Ag/TiO2 coated composite was prepared via sol-gel method in order to elucidate its application in magnetic field assisted photocatalytic degradation of dyes. Through the degradation of organic dyes, the key influences such as Ag amount, heat-treated temperature and time on the photocatalytic activity of Ag/TiO2, as well as UV irradiation time, rotational speed, dye concentration and magnetic sheet number on the photocatalytic degradation were studied. Results showed that the Ag/TiO2 with 25 wt% Ag content heat-treated at 550 °C for 60 min has the best photocatalytic activity. With the increase of UV light irradiation time, rotational speed and magnetic sheet number, the degradation rate is improved. Different dye degradation proved that the method could universally be used.

scholarly journals Remediation of textile industry organic dye waste by photocatalysis using eggshell impregnated ZnO/CuO nanocomposite

2021 ◽  
Author(s):  
Mekdes Gerawork
Keyword(s):  
Textile Industry ◽  
Organic Dyes ◽  
Uv Light ◽  
Irradiation Time ◽  
Heterogeneous Photocatalysis ◽  
Sewage Sample ◽  
Vis Spectroscopy ◽  
Debre Berhan ◽  
Highly Porous ◽  
Sorption Characteristics

Abstract Heterogeneous photocatalysis using nanocomposites is of great research interest in the treatment of industrial wastewater. The impregnated photocatalyst was produced by liquid state reaction of ZnO/CuO nanocomposite with extracted eggshells. The structure, functional group, metal composition, bandgap, and photocatalytic activity of the nanocomposites were characterized by using XRD, FTIR, AAS, and UV-vis spectroscopy, respectively in the absence and presence of eggshells. Photocatalytic degradation activities of the nanocomposites under UV light irradiation have been tested for a real sewage sample taken from Debre Berhan Textile Industry. From the results, the optimized degradation efficiency of the dye was 97.95% with 0.4 g dose of the photocatalyst, 120 min irradiation time, 120 °C temperature, and pH of 6.7. The results revealed that eggshell impregnated nanocomposite had better catalytic activity than the naked nanocomposite. This is due to the highly porous structure of eggshell biomasses and their sorption characteristics In conclusion when nanocomposites are supported by eggshell biomasses, they are excellent photocatalysts and consecutively it minimizes the contamination of organic dyes from textile effluents.

Facile Recoverable, Reusable and Efficient Heterogeneous Photocatalyst. Preparation and characterization of V2O5 added TiO2 polymer NCs

2018 ◽  
Vol 69 (10) ◽  
pp. 2662-2668
Author(s):  
S. Muthupoongodi ◽  
Liviu Mitu ◽  
T. Linda ◽  
X. Sahaya Shajan ◽  
S. Balakumar
Keyword(s):  
Rhodamine B ◽  
Congo Red ◽  
Organic Dyes ◽  
Uv Light ◽  
Active Species ◽  
Sem Analysis ◽  
X Ray Diffraction ◽  
Photocatalytic Activities ◽  
Solution Cast

TiO2 and V2O5 added polymer nanocomposites (NCs) were prepared by solution cast method and characterized by UV-Vis-DRS spectroscopy, powder X-ray diffraction, FTIR and SEM analysis. These characterization studies were employed to investigate the structure, optical property, phase formation and morphology of the prepared polymer NCs. The photocatalytic activities of the NCs were studied by observing the degradation of model dyes congo red (CR) and rhodamine B (RhB) under 365 nm of UV-light irradiation. In addition the recyclability and reusability of the catalyst were also examined. The results showed that nearly 95 % congo red and rhodamine B had undergone degradation in 160 and 80 mins of reaction time respectively. The catalyst shows better recyclability and can be reused for at least 6 times. In particular V2O5 added polymer NCs shows better catalytic activity towards the degradation of organic dyes. In the photodegradation process the photo-induced holes were considered to be the dominant active species. The reported catalytic system is found to be a simple, reusable and effective model for the degradation of dye polluted effluent water.

scholarly journals Development and characterization of probiotic mucilage based edible films for the preservation of fruits and vegetables

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Seyed Mohammad Davachi ◽  
Neethu Pottackal ◽  
Hooman Torabi ◽  
Alireza Abbaspourrad
Keyword(s):  
Fruits And Vegetables ◽  
Uv Light ◽  
Barrier Properties ◽  
Edible Films ◽  
Food Preservation ◽  
Elongation At Break ◽  
The Public ◽  
Medical Benefits ◽  
Seed Mucilage

AbstractThere is growing interest among the public and scientific community toward the use of probiotics to potentially restore the composition of the gut microbiome. With the aim of preparing eco-friendly probiotic edible films, we explored the addition of probiotics to the seed mucilage films of quince, flax, and basil. These mucilages are natural and compatible blends of different polysaccharides that have demonstrated medical benefits. All three seed mucilage films exhibited high moisture retention regardless of the presence of probiotics, which is needed to help preserve the moisture/freshness of food. Films from flax and quince mucilage were found to be more thermally stable and mechanically robust with higher elastic moduli and elongation at break than basil mucilage films. These films effectively protected fruits against UV light, maintaining the probiotics viability and inactivation rate during storage. Coated fruits and vegetables retained their freshness longer than uncoated produce, while quince-based probiotic films showed the best mechanical, physical, morphological and bacterial viability. This is the first report of the development, characterization and production of 100% natural mucilage-based probiotic edible coatings with enhanced barrier properties for food preservation applications containing probiotics.

scholarly journals Zirconium-Doped Chromium IV Oxide Nanocomposites: Synthesis, Characterization, and Photocatalysis towards the Degradation of Organic Dyes

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 117
Author(s):  
Zahir Muhammad ◽  
Farman Ali ◽  
Muhammad Sajjad ◽  
Nisar Ali ◽  
Muhammad Bilal ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Solid State ◽  
Room Temperature ◽  
Organic Dyes ◽  
Uv Light ◽  
Heterogeneous Photocatalysis ◽  
Ft Ir ◽  
Complete Mineralization

Degradation of organic dyes and their byproducts by heterogeneous photocatalysts is an essential process, as these dyes can be potentially discharged in wastewater and threaten aquatic and xerophyte life. Therefore, their complete mineralization into nontoxic components (water and salt) is necessary through the process of heterogeneous photocatalysis. In this study, Zr/CrO2 (Zirconium-doped chromium IV oxide) nanocomposite-based photocatalysts with different compositions (1, 3, 5, 7 & 9 wt.%) were prepared by an environmentally friendly, solid-state reaction at room temperature. The as-prepared samples were calcined under air at 450 °C in a furnace for a specific period of time. The synthesis of Zr/CrO2 photocatalysts was confirmed by various techniques, including XRD, SEM, EDX, FT-IR, UV-Vis, and BET. The photocatalytic properties of all samples were tested towards the degradation of methylene blue and methyl orange organic dyes under UV light. The results revealed a concentration-dependent photocatalytic activity of photocatalysts, which increased the amount of dopant (up to 5 wt.%). However, the degradation efficiency of the catalysts decreased upon further increasing the amount of dopant due to the recombination of holes and photoexcited electrons.

Photocatalytic Activity of Fe-Doped ZnO/Montmorillonite Nanocomposite for Degradation of Malachite Green

2015 ◽  
Vol 827 ◽  
pp. 19-24 ◽  
Author(s):  
Nur Afifah ◽  
Nadia Febiana Djaja ◽  
Rosari Saleh
Keyword(s):  
Photocatalytic Activity ◽  
Malachite Green ◽  
Organic Dyes ◽  
Uv Light ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Spin Resonance ◽  
Doped Zno ◽  
Co Precipitation

In this study, the photocatalytic activity of pure Fe- doped ZnO and Fe- doped ZnO/Montmorillonite nanocomposite has been investigated for the degradation of malachite green under UV light irradiation. Both photocatalysts were synthesized using co-precipitation method and characterized by X-ray diffraction, energy dispersive X-ray spectroscopy, Fourier-transform infrared absorption, and electron spin resonance. The results showed that the photocatalytic efficiency is better in the presence of montmorillonite compared to pure Fe- doped ZnO. To detect the possible reactive species involved in degradation of organic dyes control experiments with introducing scavengers into the solution of organic dyes were carried out. It is found that electron plays an important role in the degradation of malachite green.

Synthesis and Characterization of Polyaniline Film

2011 ◽  
Vol 239-242 ◽  
pp. 1382-1385
Author(s):  
Na Xu ◽  
Xiao Dong Shen ◽  
Sheng Cui
Keyword(s):  
Ammonium Persulfate ◽  
Pani Film ◽  
Cyclic Voltammograms ◽  
Ultrasonic Dispersion ◽  
Switching Speed ◽  
Color Changes ◽  
Fast Switching ◽  
Ft Ir ◽  
The Relationship

The electrochromic PANI film was prepared by emulsion polymerization with dodecyl benzene sulphonic acid (DBSA) as dopant and ammonium persulfate (APS) as initiator. Ultrasonic dispersion was adopted in the polymerization. The electrochemical properties, the surface morphology and structure of the prepared PANI film was characterized by means of Fourier Transform infrared spectroscopy (FT-IR), cyclic voltammograms (CV) and field emission scanning electron microscope (FE-SEM), respectively. The relationship between the morphology and properties of PANI film was detailedly discussed. The PANI film exhibited an excellent electrochromism with reversible color changes form yellow to purple. The PANI film also had quite good reaction kinetics with fast switching speed, and the response time for oxidation and reduction were 65 ms and 66 ms, respectively.

Growth and characterization of ammonium nickel-cobalt sulfate Tutton’s salt for UV light applications

2018 ◽  
Vol 487 ◽  
pp. 104-115 ◽  
Author(s):  
Santunu Ghosh ◽  
Michelle Oliveira ◽  
Tiago S. Pacheco ◽  
Genivaldo J. Perpétuo ◽  
Carlos J. Franco
Keyword(s):  
Uv Light ◽  
Cobalt Sulfate ◽  
Nickel Cobalt

Mechanical Characterization of UV Photopolymerized PMMA with Different Photo-Initiator Concentration

2021 ◽  
Vol 903 ◽  
pp. 11-16
Author(s):  
M.A. Manjunath ◽  
K. Naveen ◽  
Prakash Vinod ◽  
N. Balashanmugam ◽  
M.R. Shankar
Keyword(s):  
Mechanical Properties ◽  
Light Source ◽  
Polymethyl Methacrylate ◽  
Biomedical Applications ◽  
Mechanical Characterization ◽  
Uv Light ◽  
Curing Time ◽  
Uv Led ◽  
Pmma Resin

Polymethyl methacrylate (PMMA) is one among few known photo-polymeric resin useful in lithography for fabricating structures having better mechanical properties to meet the requirement in electronics and biomedical applications. This study explores the effect of Photo Initiator (PI) concentration and also curing time on strength and hardness of Polymethyl methacrylate (PMMA) obtained by UV photopolymerization of Methyl methacrylate (MMA) monomer. The UV LED light source operating at the wavelength of 364 nm is used with Benzoin Ethyl Ether (BEE) as photo initiator. The curing of PMMA resin is supported with peltier cooling device placed at the bottom of the UV light source. The characterisation study of UV photo cured PMMA is analysed through nano indenter (Agilent Technologies-G200). The current work investigates the influence of PI concentration and curing time in achieving maximum mechanical properties for UV photopolymerized PMMA.

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