The current work explores the sodium hydride mediated polycondensation of aliphatic diols with diethyl carbonate to produce both aliphatic polycarbonates and cyclic carbonate monomers. The lengths of the diol dictate the outcome of the reaction; for ethylene glycol and seven other 1,3-diols with a wide array of substitution patterns, the corresponding 5-membered and 6-membered cyclic carbonates were synthesized in excellent yield (70-90%) on a 100 gram scale. Diols with longer alkyl chains, under the same conditions, yielded polycarbonates with an ranging from 5000 to 16 000. In all cases, the macromolecular architecture revealed that the formed polymer consisted purely of carbonate linkages, without decarboxylation as a side reaction. The synthetic design is completely solvent-free without any additional post purification steps and without the necessity of reactive ring-closing reagents. The results presented within provide a green and scalable approach to synthesize both cyclic carbonate monomers and polycarbonates with possible applications within the entire field of polymer technology.
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http://dx.doi.org/10.1039/c8ra08219g | DOI Listing |
Langmuir
January 2025
College of Chemistry and Chemical Engineering, Guizhou University, Guiyang 550025, Guizhou, China.
LiFeMnPO (0 < < 1) has a high operating voltage range and theoretical energy density, but its actual capacity decreased due to its low electronic conductivity. To overcome this problem, we successfully prepared LiFeMnPO/C (LFMP/C) with a uniform carbon coating by a one-step solvothermal method using bamboo shavings as the carbon source. The results showed that heating at a reaction temperature of 180 °C for 18 h was the optimal synthesis condition to obtain LFMP/C.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Department of Chemistry, Queen's University, Kingston, ON K7L 3N6, Canada.
Tambjamines are complex bipyrrole-containing natural products that possess promising bioactive properties. Although is known to produce both cyclic tambjamine MYP1 and the linear precursor (YP1), the biosynthetic machinery used to catalyze the site-selective oxidative carbocyclization at the unactivated 1° carbon of YP1 has remained unclear. Here, we demonstrate that a three-component Rieske system consisting of an oxygenase (TamC) and two redox partner proteins is responsible for this unprecedented activity on YP1 and potentially, a non-native substrate (BE-18591).
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
Medical 3D Printing Center, Orthopedic Institute, Department of Orthopedic Surgery, The First Affiliated Hospital, School of Basic Medical Sciences, MOE Key Laboratory of Geriatric Diseases and Immunology, Suzhou Medical College, Soochow University, Suzhou, Jiangsu, 215000, China.
Stem cell implantation holds promise for enhancing bone repair, but risks of pathogen transmission and malignant cell transformation should not be ignored. Compared to stem cell implantation, recruitment of endogenous stem cells to injured sites is more critical for in situ bone regeneration. In this study, based on the acidic microenvironment of bone injury, an HG-AA-SDF-1α composite hydrogel with a dual-control intelligent switch function is developed by incorporating stromal cell-derived factor (SDF-1α), arginine carbon dots (Arg-CDs), and calcium ions (Ca) into the oxidized hyaluronic acid/gelatin methacryloyl (HG) hydrogel.
View Article and Find Full Text PDFRSC Adv
January 2025
Plasmonic Nanomaterials Laboratory, Department of Nanoscience and Technology, PSG Institute of Advanced Studies Peelamedu Coimbatore-641 004 Tamilnadu India
Escalating energy demands have often ignited ground-breaking innovations in the current era of electrochemical energy storage systems. Supercapacitors (SCs) have emerged as frontrunners in this regard owing to their exclusive features such ultra-high cyclic stability, power density, and ability to be derived from sustainable sources. Despite their promising attributes, they typically fail in terms of energy density, which poses a significant hindrance to their widespread commercialization.
View Article and Find Full Text PDFACS Omega
January 2025
Department of Biomedical Engineering, Hanyang University, Seoul 04763, Republic of Korea.
Fast-scan cyclic voltammetry (FSCV) is a widely used electrochemical technique to measure the phasic response of neurotransmitters in the brain. It has the advantage of reducing tissue damage to the brain due to the use of carbon fiber microelectrodes as well as having a high temporal resolution (10 Hz) sufficient to monitor neurotransmitter release in vivo. During the FSCV experiment, the surface of the carbon fiber microelectrode is inevitably changed by the fouling effect.
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