Photochemical Reactions of Triplet Methylene Blue with arene diazonium salts relative efficiency of the oxidation and the reduction mechanisms

1986 ◽  
Vol 328 (5-6) ◽  
pp. 661-672 ◽  
Author(s):  
H. G. O. Becker ◽  
R. Schütz ◽  
B. Tillack ◽  
V. Rehak
Keyword(s):  
Methylene Blue ◽  
Relative Efficiency ◽  
Photochemical Reactions ◽  
Diazonium Salts ◽  
Reduction Mechanisms

scholarly journals A new type of microphotoreactor with integrated optofluidic waveguide based on solid-air nanoporous aerogels

2018 ◽  
Vol 5 (11) ◽  
pp. 180802 ◽  
Author(s):  
Yaprak Özbakır ◽  
Alexandr Jonáš ◽  
Alper Kiraz ◽  
Can Erkey
Keyword(s):  
Methylene Blue ◽  
Total Internal Reflection ◽  
Incident Light ◽  
Liquid Core ◽  
Photochemical Reactions ◽  
Point Of View ◽  
Blue Dye ◽  
New Type ◽  
Aqueous Core ◽  
Low Refractive Index

In this study, we developed a new type of microphotoreactor based on an optofluidic waveguide with aqueous liquid core fabricated inside a nanoporous aerogel. To this end, we synthesized a hydrophobic silica aerogel monolith with a density of 0.22 g cm −3 and a low refractive index of 1.06 that—from the optical point of view—effectively behaves like solid air. Subsequently, we drilled an L-shaped channel within the monolith that confined both the aqueous core liquid and the guided light, the latter property arising due to total internal reflection of light from the liquid–aerogel interface. We characterized the efficiency of light guiding in liquid-filled channel and—using the light delivered by waveguiding—we carried out photochemical reactions in the channel filled with aqueous solutions of methylene blue dye. We demonstrated that methylene blue could be efficiently degraded in the optofluidic photoreactor, with conversion increasing with increasing power of the incident light. The presented optofluidic microphotoreactor represents a versatile platform employing light guiding concept of conventional optical fibres for performing photochemical reactions.

Photosensitized Delignification of Residual Lignin and Chemical Pulp from Eucalyptus grandis Wood

Holzforschung ◽  
2002 ◽  
Vol 56 (6) ◽  
pp. 595-600 ◽  
Author(s):  
D. Da Silva Perez ◽  
A. Castellan ◽  
A. Nourmamode ◽  
S. Grelier ◽  
R. Ruggiero ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Methylene Blue ◽  
Eucalyptus Grandis ◽  
Photochemical Reactions ◽  
Size Exclusion ◽  
Residual Lignin ◽  
Bleaching Process ◽  
Chemical Pulp ◽  
Exclusion Chromatography ◽  
Unbleached Pulp

Summary Bleached pulps were obtained from a Eucalyptus grandis peroxyformic/formic acid chemical pulp using oxygen, hydrogen peroxide, photosensitizers (methylene blue, Fe (II) 4,4′,4″,4‴-tetrasulfophthalocyanine, hemin, hematoporphyrin) and/or TiO2. Residual lignin of unbleached pulp, isolated and characterized by size exclusion chromatography, 31P NMR and thioacidolysis, was used to study the photochemical reactions occurring during the bleaching process. The main reactions were conversion of phenolic aromatic units into carboxylic acids and cleavage of the β-O-4 ether bonds leading to a depolymerization of the lignin framework into smaller fragments.

scholarly journals Forest canopy mitigates soil N2O emission during hot moments

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Ülo Mander ◽  
Alisa Krasnova ◽  
Jordi Escuer-Gatius ◽  
Mikk Espenberg ◽  
Thomas Schindler ◽  
...  
Keyword(s):  
Eddy Covariance ◽  
Forest Canopy ◽  
Riparian Forest ◽  
Temporal Frequency ◽  
N2o Emission ◽  
Photochemical Reactions ◽  
Content Change ◽  
Reduction Mechanisms ◽  
Eddy Covariance Measurements ◽  
Soil Emissions

AbstractRiparian forests are known as hot spots of nitrogen cycling in landscapes. Climate warming speeds up the cycle. Here we present results from a multi-annual high temporal-frequency study of soil, stem, and ecosystem (eddy covariance) fluxes of N2O from a typical riparian forest in Europe. Hot moments (extreme events of N2O emission) lasted a quarter of the study period but contributed more than half of soil fluxes. We demonstrate that high soil emissions of N2O do not escape the ecosystem but are processed in the canopy. Rapid water content change across intermediate soil moisture was a major determinant of elevated soil emissions in spring. The freeze-thaw period is another hot moment. However, according to the eddy covariance measurements, the riparian forest is a modest source of N2O. We propose photochemical reactions and dissolution in canopy-space water as reduction mechanisms.

scholarly journals Evaluation of different antioxidants during in vitro establishment of allspice (Pimenta dioica L. Merrill): a recalcitrant species

2021 ◽  
Author(s):  
Sugey Vásquez Hernández ◽  
Carlos Alberto Cruz Cruz ◽  
Maricela Santiago Santiago ◽  
Jericó Jabín Bello Bello
Keyword(s):  
Methylene Blue ◽  
Culture Medium ◽  
Control Treatment ◽  
Reduction Mechanisms ◽  
Antioxidant Agents ◽  
Randomized Experimental Design ◽  
Soluble Phenols ◽  
In Vitro Establishment ◽  
Pimenta Dioica

Objective: To evaluate the effect of different antioxidant agents during in vitro establishment of allspice (Pimenta dioica L. Merrill). Design/methodology/approach: The effect of different antioxidant agents (Methylene blue, L-cysteine, and silver nanoparticles [AnNPs]) added to Murashige and Skoog culture medium at different concentrations were studied during axenic establishment of P. dioica. A completely randomized experimental design was used. All trials were performed in triplicate. The percentage of survival, oxidation, contamination was determined, the phenols content, antioxidant capacity and lipid peroxidation. Results: The highest survival occurred with the addition of L-cysteine. The lowest percentages oxidation were observed in explants treated with L-cysteine. Treatments with 100 and 200 mg L-1 AgNPs had the lowest contamination values. L-cysteine and 50 and 100 mg L-1 AgNPs resulted in an increase in the content of soluble phenols. The highest contents of cell wall-linked phenols were obtained in treatments with 200 mg L-1 methylene blue, L-cysteine, and 200 mg L-1 AgNPs. In this study, all treatments had a reaction of scavenging/reduction mechanisms free radicals. The highest content of malondialdehydes was observed in the control treatment and 200 mg L-1 methylene blue. The highest content of malondialdehydes was observed in the control treatment and 200 mg L-1 methylene blue. Limitations on study/implications: The highest percentage of oxidation was observed in the control treatments, 100 and 200 mg L-1 methylene blue, causing cell death. Findings/conclusions: The addition of L-cysteine to the culture medium is alternative to reduce oxidation during in vitro introduction of P. dioica.

The effect of electronic structure changes in NaInO2and NaIn0.9Fe0.1O2on the photoreduction of methylene blue

2014 ◽  
Vol 2 (24) ◽  
pp. 9331-9337 ◽  
Author(s):  
Jonathan W. Lekse ◽  
Barry J. Haycock ◽  
James P. Lewis ◽  
Douglas R. Kauffman ◽  
Christopher Matranga
Keyword(s):  
Methylene Blue ◽  
Electronic Structure ◽  
Organic Pollutants ◽  
Photochemical Reactions ◽  
Promising Method ◽  
Structure Changes ◽  
Degradation Of Dyes ◽  
Delafossite Oxides

Substitution into delafossite oxides is one promising method for the generation of improved catalysts for photochemical reactions such as the degradation of dyes and organic pollutants.

A SEM and Light Microscope Study of the Epidermal Leaf Structures of the Carnivorous Plant, Sarracenia purpurea, L.

1971 ◽  
Vol 29 ◽  
pp. 358-359
Author(s):  
B. J. Panessa ◽  
J. F. Gennaro
Keyword(s):  
Methylene Blue ◽  
Toluidine Blue ◽  
Outer Surface ◽  
Microscope Study ◽  
Light Microscope ◽  
Carnivorous Plant ◽  
Sarracenia Purpurea ◽  
Inner Surface

Tissue from the hood and sarcophagus regions were fixed in 6% glutaraldehyde in 1 M.cacodylate buffer and washed in buffer. Tissue for SEM was partially dried, attached to aluminium targets with silver conducting paint, carbon-gold coated(100-500Å), and examined in a Kent Cambridge Stereoscan S4. Tissue for the light microscope was post fixed in 1% aqueous OsO4, dehydrated in acetone (4°C), embedded in Epon 812 and sectioned at ½u on a Sorvall MT 2 ultramicrotome. Cross and longitudinal sections were cut and stained with PAS, 0.5% toluidine blue and 1% azure II-methylene blue. Measurements were made from both SEM and Light micrographs.The tissue had two structurally distinct surfaces, an outer surface with small (225-500 µ) pubescent hairs (12/mm2), numerous stoma (77/mm2), and nectar glands(8/mm2); and an inner surface with large (784-1000 µ)stiff hairs(4/mm2), fewer stoma (46/mm2) and larger, more complex glands(16/mm2), presumably of a digestive nature.

Sign in / Sign up

Export Citation Format

Share Document