Category Ranking
98%
Total Visits
921
Avg Visit Duration
2 minutes
Citations
20
Article Abstract
The ascorbic acid (AA) and hydroxyl peroxide (HO) redox pair induced free radical grafting reaction is a promising approach to conjugate phenolic groups with chitosan (CS). In order to reveal the exact mechanisms of the AA/HO redox pair induced grafting reaction, free radicals generated in the AA/HO redox system were compared with hydroxyl radical (OH) produced in the Fe/HO redox system. Moreover, the structural and physicochemical properties of caffeic acid grafted CS (CA-g-CS) synthesized in these two redox systems were compared. Results showed that only ascorbate radical (Asc) was produced in the AA/HO system. The reaction between Asc and CS produced novel carbon-centered radicals, whereas no new free radicals were detected when OH reacted with CS. Thin layer chromatography, UV-vis, Fourier transform infrared, and nuclear magnetic resonance spectroscopic analyses all confirmed that CA was successfully grafted onto CS through Asc. However, CA could be hardly grafted onto CS via OH. CA-g-CS synthesized through Asc exhibited lower thermal stability and crystallinity than the reaction product obtained through OH. For the first time, our results demonstrated that the synthesis of CA-g-CS in the AA/HO redox system was mediated by Asc rather than OH.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/acs.jafc.7b05135 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Molecular Engineering Empowers Phenanthraquinone Organic Cathodes with Exceptional Cycling Stability for Lithium- and Aqueous Zinc-Ion Batteries.
Adv Sci (Weinh)
September 2025
School of Materials Science and Engineering, Tianjin Key Laboratory of Composite and Functional Materials, State Key Laboratory of Advanced Materials for Intelligent Sensing, Tianjin University, Tianjin, 300072, China.
Organic electrode materials have garnered great attention in recent years, owing to their resource sustainability, structural diversity, and superior compatibility with various ionic species. Among them, quinone-based compounds have attracted particular interest. Notably, compared with para-quinone analogs (e.
View Article and Find Full Text PDFCovalently Supported Phenazine for Electrochemical Capture of Low Concentration CO.
ACS Appl Mater Interfaces
September 2025
School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, P. R. China.
Electrochemical CO capture (eCC) excels in selectivity, reversibility, low-temperature operation, and reusability, yet liquid-phase systems struggle with mass transfer limitations. In this study, a phenazine-based capture agent was chemically grafted onto carboxylated carbon nanotubes, achieving an active loading of 4.4 wt %.
View Article and Find Full Text PDFDNA Damage Markers, Thioredoxin System, and Inflammation in a Population Exposed to High Indoor Radon Levels.
Radiat Res
September 2025
Department of Biology, Faculty of Biology and Agriculture, Universitas Nasional, Jakarta, Indonesia.
High radon levels in the environment can lead to adverse biological effects such as DNA damage, thereby increasing cancer risk, especially lung cancer. This study focused on Tande-Tande sub-village in Mamuju, West Sulawesi, Indonesia, an area known for naturally high indoor radon concentrations, where inhabitants have been chronically exposed to radon throughout their lives. Blood samples from 38 subjects in Tande-Tande sub-village and the control area, Topoyo village, were examined.
View Article and Find Full Text PDFDual-signal colorimetric sensor based on Fe,Ce-CDs for ultra-sensitive detection of nitrite in tobacco.
Mikrochim Acta
September 2025
Faculty of Life Science and Technology, Kunming University of Science and Technology, Yunnan Province, 650500, China.
Iron-cerium co-doped carbon dots (Fe,Ce-CDs) were synthesized by one-step hydrothermal method using tartaric acid and L-tryptophan as ligands. Fe,Ce-CDs shows excellent peroxidase-like (POD) activity and nitrite (NO) can promote the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) to its blue oxidation product (oxTMB) due to the formation of ∙NO free radical. NO further react with oxTMB to form a yellow color via diazotization resulting in the absorbance Change at 450 nm.
View Article and Find Full Text PDFRedox-driven mineral and organic associations in Jezero Crater, Mars.
Nature
September 2025
Los Alamos National Laboratory, Los Alamos, NM, USA.
The Perseverance rover has explored and sampled igneous and sedimentary rocks within Jezero Crater to characterize early Martian geological processes and habitability and search for potential biosignatures. Upon entering Neretva Vallis, on Jezero Crater's western edge, Perseverance investigated distinctive mudstone and conglomerate outcrops of the Bright Angel formation. Here we report a detailed geological, petrographic and geochemical survey of these rocks and show that organic-carbon-bearing mudstones in the Bright Angel formation contain submillimetre-scale nodules and millimetre-scale reaction fronts enriched in ferrous iron phosphate and sulfide minerals, likely vivianite and greigite, respectively.
View Article and Find Full Text PDF