scholarly journals Comparative Solid Phase Photocatalytic Degradation of Polythene Films with Doped and Undoped TiO2Nanoparticles

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Wasim Asghar ◽  
Ishtiaq A. Qazi ◽  
Hassan Ilyas ◽  
Aftab Ahmad Khan ◽  
M. Ali Awan ◽  
...  
Keyword(s):  
Photocatalytic Degradation ◽  
Ftir Spectroscopy ◽  
Uv Radiation ◽  
Uv Irradiation ◽  
Weight Reduction ◽  
Solid Phase ◽  
Sem Analysis ◽  
Artificial Light ◽  
Metal Doping

Comparative photocatalytic degradation of polythene films was investigated with undoped and metal (Fe, Ag, and Fe/Ag mix) doped TiO2nanoparticles under three different conditions such as UV radiation, artificial light, and darkness. Prepared photocatalysts were characterized by XRD, SEM, and EDS techniques. Photocatalytic degradation of the polythene films was determined by monitoring their weight reduction, SEM analysis, and FTIR spectroscopy. Weight of PE films steadily decreased and led to maximum of 14.34% reduction under UV irradiation with Fe/Ag mix doped TiO2nanoparticles and maximum of 14.28% reduction under artificial light with Ag doped TiO2nanoparticles in 300 hrs. No weight reduction was observed under darkness. Results reveal that polythene-TiO2compositing with metal doping has the potential to degrade the polythene waste under irradiation without any pollution.

Mechanism of PVC’s Solid-Phase Photocatalytic Degradation Enhanced by Plasma

2007 ◽  
Vol 544-545 ◽  
pp. 155-158
Author(s):  
Xiao Jing Li ◽  
Guan Jun Qiao ◽  
Jie Rong Chen
Keyword(s):  
Free Radicals ◽  
Photocatalytic Degradation ◽  
Solid Phase ◽  
Ambient Air ◽  
Nitrogen Plasma ◽  
Sem Analysis ◽  
Electron Microscopic ◽  
Pvc Film ◽  
Spin Resonance ◽  
Scanning Electron Microscopic

The solid-phase photocatalytic degradation of poly (vinyl chloride) (PVC) films was investigated in ambient air. The photodegradation of the PVC and PVC-TiO2 was compared with that of plasma-treated PVC and plasma-treated PVC-TiO2 performing a weight loss monitoring and scanning electron microscopic (SEM) analysis. The SEM of the PVC-TiO2 film treated by plasma showed many cracks on the surface after photodegradation. Furthermore, the surface wettability and surface structure of PVC after nitrogen plasma treatment was characterized by contact angle, surface tension, and electron spin resonance (ESR). The experiment indicated that the surface free energy and wettability of PVC treated by plasma increased greatly. ESR revealed that the signal of radicals on the surface of the plasma-treated PVC film was enhanced after treatment. The free radicals on the surface of plasma-treated PVC possibly decreased the activating energy of photocatalytic reaction, which belongs to the free radicals reaction, because the chemical activity of the free radicals was high. According to these findings, a mechanism on the photodegradation of plasma-treated PVC-TiO2 is proposed.

Molecular Transformations in DNA under the Influence of UV-radiation

2020 ◽  
Vol 04 ◽  
Author(s):  
Vigen G. Barkhudaryan ◽  
Gayane V. Ananyan ◽  
Nelli H. Karapetyan
Keyword(s):  
Uv Radiation ◽  
Uv Irradiation ◽  
Absorption Spectroscopy ◽  
Calf Thymus Dna ◽  
Dilute Solutions ◽  
Concentrated Solutions ◽  
Buffer Solution ◽  
Low Concentration ◽  
Calf Thymus ◽  
Dna Solutions

Background: The processes of destruction and crosslinking of macromolecules occur simultaneously under the influence of ultraviolet (UV) radiation in synthetic polymers, dry DNA and their concentrated solutions. Objective: The effect of UV radiation on calf thymus DNA in dilute solutions subjected to UV- irradiation was studied in this work. Method: The calf thymus DNA was studied in dilute solutions using viscometry, absorption spectroscopy and electrophoresis. Results: It was shown, that at a low concentration of DNA in the buffer solution ([DNA] = 85 μg / ml) under the influence of UV radiation, the processes of destruction of macromolecules and an increase in their flexibility predominate, which is accompanied by a gradual decrease in the viscosity of their solution. In addition, due to the low concentration of the solution, intramolecular crosslinking of macromolecules predominates, which also reduces their size and, consequently, the viscosity of the solution. Conclusion: It was concluded, that in dilute DNA solutions, due to the predominance of the processes of intramolecular crosslinking of macromolecules over intermolecular, only constant processes of decreasing the sizes of DNA macromolecules occur. As a result, its solubility remains virtually unchanged during UV irradiation. The described comments are also excellently confirmed by the results of absorption spectroscopy and electrophoresis

scholarly journals Effect of Water Leaching on Photodegraded Scots Pine and Spruce Timbers Monitored by FTIR Spectroscopy

Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 833
Author(s):  
Edina Preklet ◽  
László Tolvaj ◽  
Eszter Visi-Rajczi ◽  
Tamás Hofmann
Keyword(s):  
Ftir Spectroscopy ◽  
Scots Pine ◽  
Uv Irradiation ◽  
Chemical Elements ◽  
Uv Light ◽  
Carbonyl Groups ◽  
Water Leaching ◽  
Absorption Bands ◽  
Chemical Changes ◽  
Absorption Increase

The goal of this research was the systematic study and comparison of the divided individual effects of UV light irradiation and water leaching during artificial weathering. Spruce (Picea abies Karst.) and Scots pine (Pinus sylvestris L.) samples were irradiated by ultraviolet (UV) light. Another sequence of samples was treated with the combination of UV irradiation and water leaching. The total extent of UV treatment was 20 days for both series of samples. Time relation of UV irradiation and water leaching was 2:1. The chemical changes were observed by FTIR spectroscopy. The difference spectrum was used for determination of the chemical changes. Degradation of lignin was greater for the leached samples than for the pure UV treated samples. Scots pine suffered greater lignin degradation than spruce, and produced higher absorption increase on the absorption region of unconjugated carbonyls. The unconjugated carbonyl groups were the most responsive chemical elements to leaching. Spruce was more susceptible to leaching of unconjugated carbonyl groups than Scots pine. Two absorption bands of unconjugated carbonyl groups at 1706 and 1764 cm−1 wavenumbers were produced by photodegradation. The absorption band at 1764 cm−1 was more sensitive to water leaching than the band at 1706 cm−1.

scholarly journals In situ ATR-FTIR study of H2O and D2O adsorption on TiO2 under UV irradiation

2015 ◽  
Vol 17 (35) ◽  
pp. 22940-22946 ◽  
Author(s):  
Hamza Belhadj ◽  
Amer Hakki ◽  
Peter K. J. Robertson ◽  
Detlef W. Bahnemann
Keyword(s):  
Ftir Spectroscopy ◽  
Uv Irradiation ◽  
Deuterium Oxide ◽  
Ftir Study ◽  
Adsorption Of Water

The adsorption of water and deuterium oxide on TiO2 surfaces was investigated in the dark as well as under UV(A) irradiation using in situ ATR-FTIR spectroscopy under oxygen and oxygen free conditions.

Solid-phase photocatalytic degradation of polyethylene–goethite composite film under UV-light irradiation

2009 ◽  
Vol 172 (2-3) ◽  
pp. 1424-1429 ◽  
Author(s):  
G.L. Liu ◽  
D.W. Zhu ◽  
S.J. Liao ◽  
L.Y. Ren ◽  
J.Z. Cui ◽  
...  
Keyword(s):  
Composite Film ◽  
Photocatalytic Degradation ◽  
Solid Phase ◽  
Uv Light ◽  
Light Irradiation ◽  
Uv Light Irradiation

Photocatalytic Degradation of Humic Acid Using Ti/Anodized TiO2 Metal Plate with Fe-Doping

2012 ◽  
Vol 724 ◽  
pp. 33-36 ◽  
Author(s):  
Jong Oh Kim ◽  
Seung Pil Choi ◽  
Geon Tae Kim ◽  
Yong Hak Kim
Keyword(s):  
Humic Acid ◽  
Photocatalytic Degradation ◽  
Surface Area ◽  
Acid Concentration ◽  
Uv Irradiation ◽  
Metal Plate ◽  
Fe Doping ◽  
Treatment Efficiency ◽  
Acid Degradation ◽  
Hypochromic Effect

We evaluated the treatment efficiency of humic acid using Ti and anodized TiO2metal plate with/without Fe-doping. Variation of humic acid concentration after 60 minutes of UV irradiation in the case of Ti only, Fe-Ti, TiO2only and Fe-TiO2was about 3.0%, 5.5%, 9.8% and 9.2%, respectively. . It is found that hypochromic effect was revealed in all cases with respect to doping time. Fe doping method is considered to be effective for humic acid degradation in spite of relatively low surface area of Ti and anodized TiO2metal plate.

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