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Synergetic effects of photo-oxidation and biodegradation on failure behavior of polyester coating in tropical rain forest atmosphere

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Journal of Materials Science & Technology 2021年第5期64卷 195-202页

作者： Lin Lu Qianqian Liu Corrosion and Protection Center University of Science and Technology BeijingBeijing100083China State Key Laboratory of Metal Material for Marine Equipment and Application Anshan114000China

This work aimed to study the comprehensive effects of photo-oxidation and biodegradation on different failure stages of polyester coatings,which were exposed to the tropical rainforest *** surface morphology,aging products,local aging characteristics and electrochemical behavior of the coatings were characterized with scanning electron microscope(SEM),fourier transform infrared spectroscopy(FTIR),electrochemical impedance spectroscopy(EIS)and high-resolution dispersive Raman *** results showed that the surface of coatings became rougher and fungal hyphae distributed more densely on surface with the increasing of exposure *** the aspect of polymer structure,the ultraviolet radiation destroyed the main chain of polyester through the photo-oxidation process,resulting in the breakage of aliphatic ester bonds and the formation of ***,the metabolites of fungi can promote the hydrolysis of oligomers produced by the *** a short,the photo-oxidation could facilitate the biodegradation of the *** the synergistic effect of UV photo-oxidation and fungal biodegradation,a rapid diffusion tunnel between the coating surface and the metal substrate was established at the pore defects of the coating,which finally accelerated the corrosion failure process of the *** main corrosion products includeα-Fe_(2)O_(3),ZnO and Zn_(5)(OH)_(6)(CO_(3))_(2).

关键词： Polyester coating Fungus Biodegradation photo-oxidation Microbiologically influenced corrosion Tropical rainforest

Accelerating Role of Clay in photo-oxidation of Polypropylene/Clay Multifilament Yarns

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Chinese Journal of Polymer Science 2014年第5期32卷 609-619页

作者： S.Aslanzadeh R.Semnani Rahbar M.Nazi Department of Textile and Leather Faculty of Chemistry and Petrochemical Engineering Standard Research Institute (SRI)

photo-oxidative degradation of polypropylene/clay multifilament yarns containing different amounts of clay was investigated. These samples and pure polypropylene （PP） multifilametns were exposed to long wavelength radiations （λ〉 300 nm） under atmospheric condition of constant temperature and relative humidity. The photo-oxidative stability was studied using FTIR spectroscopy, tensile testing and microscopy. The results indicate that the addition of clay particles decreases the stability of PP/clay composites to photo-oxidative degradation according to comparison with pure PP. From FTIR study and tensile properties, it was also found that the multifilaments with higher clay loading reveals a faster loss of mechanical properties, higher photo-oxidative product formation and more reduction in the induction time of photo-oxidation. Moreover, the crack formation on surface of irradiated filaments corresponds well to the conclusions in tensile properties and FTIR characterization.

关键词： photo-oxidation Polypropylene Multifilarnent yams Nanoclay UV radiation.

Dye-sensitized photo-oxidation of disulfiram

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Chinese Journal of Chemistry 1995年第5期13卷 464-467页

作者： CHOBISA C.S.BHARDWAJ Rajesh PUNJABI Pinki B.AMETA Suresh C. Department of Chemistry College of Science Sukhadia University Udaipur 313001 (Raj.) IndiaDepartment of Chemistry College of Science Sukhadia University Udaipur 313001 (Raj.) IndiaDepartment of Chemistry College of Science Sukhadia University Udaipur 313001 (Raj.) IndiaDepartment of Chemistry College of Science Sukhadia University Udaipur 313001 (Raj.) IndiaDepartment of Chemistry College of Science Sukhadia University Udaipur 313001 (Raj.) India

Dye-sensitized photo-oxidation of disulfiram has been carried out under various reaction conditions including change in solvents and sensitizers. The product has been isolated and characterized by its physical, chemical and spectral data. To confirm the participation of singlet-oxygen in the reaction, the experiment has also been carried out in the presence of various singlet oxygen scavengers.

关键词： Dye-sensitization photo-oxidation disulfiram

Heterogeneous photooxidation of Phenol by Catalytic Membranes

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过程工程学报 2006年第4期6卷 645-650页

作者： Enrica Fontananova Enrico Drioli Laura Donato Marcella Bonchio Mauro Carraro Gianfranco Scorrano Institute on Membrane Technology of the National Research Council (ITM-CNR) Via P.Bucci 17/C 87030Rende (CS) Italy Department of Chemical Engineering and Materials University of CalabriaVia P. BucciRende (CS)Italy ITM-CNR (sect.) c/o University of PadovaVia Marzolo 135131PadovaItaly

In this work the heterogenization in polymeric membranes of decatungstate,a photocatalyst for oxidation reactions,was *** state characterization techniques confirmed that the catalyst structure was preserved within the polymeric *** catalytic membranes were successfully applied in the aerobic photo-oxidation of phenol,one of the main organic pollutants in wastewater,providing stable and recyclable photocatalytic *** dependence of the phenol degradation rate by the catalyst loading and transmembrane pressure was *** comparison with homogeneous reaction,the catalyst heterogenized in membrane appears to be more efficient concerning the rate of phenol photodegradation and mineralization.

关键词： photo-oxidation decatungstate catalytic membrane phenol wastewater

photochemistry of insecticide imidacloprid: direct and sensitized photolysis in aqueous medium

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Journal of Environmental Sciences 2004年第4期16卷 539-542页

作者： ZHENGWei LIUWei-ping WENYue-zhong Sang-jinLee InstituteofEnvironmentalScience ZhejiangUniversityHangzhou310027China DepartmentofEnvironmentalSciences UniversityofCaliforniaRiversideCA92521USA LouisianaWaterResourcesResearchInstitute LouisianaStateUniversityBatonRougeLA70803USA

The direct and sensitized photodegradations of imidacloprid, 1-(6-chloro-3-pyridinylmethyl)-N-nitro-2-imidazolidinimine, were investigated in aqueous solution and with and without various photo-sensitizers. Results of the study revealed that the intensity of lamp-house and irradiation wavelength had significant effects on the photolysis of imidacloprid. Complete degradation of 20 mg/L imidacloprid in aqueous phase was observed in 40 min under ultraviolet(UV) irradiation system, suggesting the ultraviolet ray played significant role in direct photolysis of imidacloprid. The additions of various photo-sensitizers lead to improve the degradation efficiency of imidacloprid under the irradiation of black light fluorescent lamp. TiO 2 was the most efficient in the photo-catalytic degradation of imidacloprid among other photo-sensitizers in used this study. However, addition of acetone inhibited the photolysis of imidacloprid under the irradiation of UV, indicating the occurrence of competition between acetone and imidacloprid for photos. Mineralization of the imidacloprid was examined to clarify the final photochemical degradation products of the insecticide which were CO 2, Cl- and NO- 3. Complete photo-oxidation of nitrogen to NO- 3 occurred very slowly via the intermediate formation of NH+ 4 and NO- 2.

关键词： imidacloprid photolysis photo-sensitizers photo-oxidation mineralization

Surface modification of blue TiO2 with silane coupling agent for NOx abatement

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Progress in Natural Science:Materials International 2021年第2期31卷 230-238页

作者： Adriana Martinez-Oviedo Yuwaraj K.Kshetri Bhupendra Joshi Soo Wohn Lee Department of Environmental and Bio-Chemical Engineering Sun Moon University Research Center for Eco Multifunctional Nanomaterials Sun Moon University Department of Fusion Science and Technology Sun Moon University

The role of hydroxyl-functionalization of reduced TiO2(Blue TiO2) for the photocatalytic oxidation of toxic NOx was systematically explored in the present study. A hydrogenation technique was used to reduce the rutile phase in P25 TiO2giving rise to a Magneli phase. Then, the process was followed by the surface functionalization of the Blue TiO2with Trimethoxy(Propyl) Silane(TPS). The fabricated nanoparticles were structurally characterized,and photocatalytically tested for NOx abatement. OH-functionalized Blue TiO2showed strong photo-oxidation of NOx with NOx removal efficiency of 80.2%. The broad-band light absorption(UV and visible) and the formation of a higher number of radicals on the surface of OH-functionalized Blue TiO2made the material more efficient than other samples. In addition, the lowest NO2selectivity of 2.7% proved the effective suppression of toxic NO2and formation of nitrate ions. The reusability test was carried out for five cycles of 1 h and had 10% loss in NOx removal efficiency. The role of surface OH groups for the oxidation of NO and NO2has been discussed in this manuscript. A possible mechanism for NOx photo-oxidation is proposed based on FTIR, ESR, and ion chromatography test.

关键词： Blue TiO 2 OH-Functionalization NOx photo-oxidation Hydroxyl radicals

GUN4 Is Required for Posttranslational Control of Plant Tetrapyrrole Biosynthesis

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Molecular Plant 2009年第6期2卷 1198-1210页

作者： Enrico Peter Bernhard Grimm Institute of Biology/Plant Physiology Humboldt University Philippstr. 13 Building 12 D 10115 Berlin Germany

In aerobic photosynthetic organisms, GUN4 binds the chlorophyll intermediates protoporphyrin and Mg protoporphyrin, stimulates Mg chelatase activity, and is implicated in plastidic retrograde signaling. GUN4 expression is most abundant in young and greening tissues and parallels the activity of 5-aminolevulinic acid （ALA） ALA and Mg porphyrin biosynthesis during photoperiodic growth. We explored function and mode of action of GUN4 using GUN4- deficient and overexpressing plants. GUN4 overexpression leads to a general activation of the enzymes of chlorophyll biosynthesis. During photoperiodic growth GUN4 deficiency prevents ALA synthesis and chlorophyll accumulation. All these metabolic changes do not correlate with altered gene expression or changes of protein abundance in tetrapyrrole biosynthesis. While ALA feeding fails to compensate GUN4 deficiency during light-dark growth, this approach results in chlorophyll accumulation under continuous dim light. A new model defines the involvement of GUN4 in posttranslational regulation of ALA and Mg porphyrin synthesis, to sustain chlorophyll synthesis, namely under varying environmental conditions.

关键词： Tetrapyrrole biosynthesis chlorophyll Mg porphyrin branch photo-oxidation chloroplasts

Synthesis and Characterization of Lu3N@C80O

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Chinese Journal of Chemistry 2017年第9期35卷 1459-1462页

作者： Jiaxin Zhuang Yaofeng Wang Jinqian Yao Ting Yang Ning Chen Laboratory of Advanced Optoelectronic Materials College of Chemistry Chemical Engineering and Materials Science Soochow University Suzhou Jiangsu 215123 China

Oxygenated hollow cage fullerenes have been intensively studied due to their applications in biomedicine in recent years. Clusterfullerenes have become a focus of endohedral fullerene researches for their exceptionally high yield and thermal stabilities. However, oxide derivatives of clusterfullerene remain unexplored to date. Herein, we present the photochemical synthesis of an oxide derivative of clusterfullerene, Lu3N@C80O, for the first time. The compound was characterized by matrix-assisted laser desorption ionization time-of-flight mass spectrometry, UV-vis-NIR, cyclic vokammetry, and FTIR spectroscopy. The results suggest that one oxygen atom bridges with the fullerene cage after the oxidation of Lu3N@C80. Moreover, the oxidation has a major impact on the electrochemical behavior of Lu3N@C80.

关键词： fullerenes photo-oxidation monooxide derivative

THE FTIR STUDIES OF photo-OXIDATIVE DEGRADATION OF POLYPROPYLENE

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Chinese Journal of Polymer Science 1988年第3期6卷 285-288页

作者：闻再庆胡兴洲沈德言 Academia Sinica Beijing Institute of chemistry

The photo-oxidative degradation process of polypropylene film containing iron ions was investigated via FTIR and absorbance substraction technique. It is shown that the iron ions play an important role in the decomposition of hydroperoxide and the increase of the degradation rate of polypropylene film. The amorphous region of PP film undergoes degradation prior to the crystalline one.

关键词： Polypropylene photo-oxidation FTIR.