A series of polyimides were synthesized by a polycondensation reaction using various aromatic dianhydrides and diamines containing bulky cardo and hydroxyl groups. The imidization and chemical structure of the polyimides were confirmed by NMR and FT-IR. The thermal and gas properties of the polyimides were measured by time-lag, XRD, TGA, and DSC studies. The polyimides showed excellent solubility in common organic solvents and high thermal stability. The CO2 selectivity of HPI membrane was higher than traditional polyimides. In particular, the incorporation of hydroxyl groups improved the CO2 permeability of the polyimide due to increased carbon dioxide solubility. The HPI was thermally converted to polybenzoxazole (PBO) at 450 °C.
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http://dx.doi.org/10.1166/jnn.2015.10260 | DOI Listing |
Org Lett
January 2025
Department of Chemistry, Xihua University, Chengdu 610039, P. R. China.
A novel approach for the synthesis of pyrone and indanone derivatives utilizing Fe(III)-catalyzed reductive radical ring expansion of olefins and cyclopropenone has been proposed. The preliminary mechanism study shows that the alkyl radical is formed by hydrogen atom transfer, which can open the tension ring and then generate the intermediate. There are two paths for the intermediate: when there is a hydroxyl group at the β-position of the olefin, the reaction produces pyrones, and otherwise 1-indanone is generated.
View Article and Find Full Text PDFSmall Methods
January 2025
National Engineering Research Center for Colloidal Materials, Key Laboratory of Colloid and Interface Chemistry (Ministry of Education), School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, China.
Exploring potential third-order nonlinear optical (NLO) materials attracts ever-increasing attention. Given that the atomically precise and rich adjustable structural features of silver nanoclusters (Ag NCs), as well as the unique π-electron conjugated system of carbon-based nanomaterials, a supramolecular co-assembly amplification strategy to enhance the luminescent intensity and NLO performance of the hybrids of the two components, are constructed and the relationship between structures and optical properties are investigated. By combining water soluble Ag NCs [(NH)[Ag(mna)] (Hmna = 2-mercaptonicotinic acid, abbreviated to Ag─NCs hereafter) containing uncoordinated carboxyl groups with water-soluble fullerene derivatives modified with multiple hydroxyl groups (fullerenols, C─OH), the π-electron delocalization is expanded owing to non-covalent hydrogen bonding effect between Ag6─NCs and C─OH, which provides a feasible basis for realizing the NLO response.
View Article and Find Full Text PDFFoods
December 2024
Department of Marine Bio Food Science, Gangneung-Wonju National University, 7 Jukheon-gil, Gangneung 25457, Gangwon-do, Republic of Korea.
Commercial ascorbyl-6-O-esters (AEs) are composed of saturated fatty acids with relatively high melting points, resulting in limited solubility in lipophilic media. Therefore, a lipase-catalysed synthesis and purification method for ascorbyl-6-O-oleate (AO) was proposed in this study. The esterification synthesis (i.
View Article and Find Full Text PDFInt J Mol Sci
January 2025
Department of Biochemistry and Molecular Biology, Faculty of Science and Informatics, University of Szeged, H-6701 Szeged, Hungary.
The red blood cell (RBC) membrane is unique and crucial for maintaining structural-functional relationships. Maternal smoking induces significant changes in the morphological, rheological, and functional parameters of both maternal and foetal RBCs, mainly due to the continuous generation of the free radicals. The major aim of this study was to follow the consequences of a secondary stressor, like fungal infection, on the already compromised RBC populations.
View Article and Find Full Text PDFInt J Mol Sci
December 2024
Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy.
ROS (i.e., reactive oxygen species) scavenging is a key function of various Mn-based enzymes, including superoxide dismutases (SODs) and catalases, which are actively linked to oxidative stress-related diseases.
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