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This article presents an experimental study on the relaxation dynamics of a series of random copolymers based on bio-friendly comonomers with interesting gas barrier properties. We analyze the relaxation response in the glassy and ultraviscous regime of poly (trimethylene furanoate/sebacate) random copolymers via dielectric spectroscopy. We report lower values of dynamic fragility [a dimensionless index introduced in 1985 (Angell, Relaxations in Complex Systems, 1985)] in comparison to popular polyesters widely used in industry, such as poly (ethylene terephthalate), suggesting that the amorphous phase of these furanoate-based polyesters adopt an efficient chain packing. This is consistent with their low permeability to gases. We also discuss on different equations (phenomenological and theory-based approaches) for fitting the temperature-evolution of the alpha relaxation time.
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http://dx.doi.org/10.3389/fchem.2022.921787 | DOI Listing |
J Phys Chem Lett
September 2025
School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, U.K.
The electron-deficient oxidant 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) has recently emerged as a promising visible-light photoredox catalyst. However, its excited-state behavior remains poorly understood. Here, we investigate the ultrafast dynamics of photoexcited DDQ in acetonitrile using transient electronic and infrared absorption spectroscopy, supported by quantum chemical calculations.
View Article and Find Full Text PDFAnnu Rev Entomol
September 2025
5Department of Entomology, University of Georgia, Athens, Georgia, USA; email:
Wetlands and their aquatic arthropods are threatened by climate change (temperature, precipitation). In this review, we first synthesize the literature on environmental controls on wetland arthropods (hydroperiod, temperature, dissolved oxygen) and then assess how these controls operate across freshwater wetlands from different global biomes (tropical/subtropical, temperate, high latitude/altitude, and dry climates) and how changes in climates alter arthropod fauna with consequent modifications to wetland ecosystem functions (decomposition, food web dynamics). We also describe ways to develop bioassessment of climate change impacts on wetlands.
View Article and Find Full Text PDFACS Nano
September 2025
International School of Microelectronics, Dongguan University of Technology, Dongguan 523808, China.
Mimicking human brain functionalities with neuromorphic devices represents a pivotal breakthrough in developing bioinspired electronic systems. The human somatosensory system provides critical environmental information and facilitates responses to harmful stimuli, endowing us with good adaptive capabilities. However, current sensing technologies often struggle with insufficient sensitivity, dynamic response, and integration challenges.
View Article and Find Full Text PDFJ Biomol NMR
September 2025
Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA.
Biomolecular dynamics in the microsecond-to-millisecond (µs-ms) timescale are linked to various biological functions, such as enzyme catalysis, allosteric regulation, and ligand recognition. In solution state NMR, Carr-Purcell-Meiboom-Gill (CPMG) relaxation dispersion experiments are commonly used to probe µs-ms timescale motions, providing detailed kinetic, thermodynamic, and mechanistic information at the atomic level. For investigating conformational dynamics in high-molecular-weight biomolecules, methyl groups serve as ideal probes due to their favorable relaxation properties, and C CPMG relaxation dispersion is widely employed for characterizing dynamics in selectively CH-labeled samples.
View Article and Find Full Text PDFACS Macro Lett
September 2025
Pritzker School of Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, United States.
Introducing dynamic covalent chemistries into polymer networks allows access to complex linear viscoelasticity, owing to the reversible nature of the dynamic bonds. While this macroscopic mechanical behavior is influenced by the dynamic exchange of these chemistries, connecting the microscopic dynamics to the bulk properties is hindered by the time scale conventional techniques can observe. Here, light scattering passive microrheology is applied to probe short-time dynamics of dynamic covalent networks that consist of telechelic benzalcyanoacetate (BCA) Michael acceptors and thiol-functionalized cross-linkers.
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