A novel phthalonitrile-terminated polyaryl ether nitrile (PEN-Ph) was synthesized and characterized. The crystallization behavior coexisting with the crosslinking behavior in the PEN-Ph system was confirmed by rheological measurements. DSC was applied to study the crystallization kinetics and crosslinking reaction kinetics. Through the Avrami equation modified by Jeziorny, the nonisothermal crystallization kinetics were analyzed, and the Avrami exponent of about 2.2 was obtained. The analysis results of more intuitive polaring optical microscopy (POM) and SEM indicated that the shape of the crystals is similar to spherical. Moreover, the activation energy of the crystallization behavior and crosslinking behavior were obtained by the Kissinger method, and the values were about 152.7 kJ·mol and 174.8 kJ·mol, respectively. This suggests that the activation energy of the crystallization behavior is lower than that of the crosslinking behavior, indicating that the crystallization behavior is more likely to occur than the crosslinking behavior and the crystals of PEN-Ph can be self-crosslinked to form single-polymer composites.
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http://dx.doi.org/10.3390/polym10060640 | DOI Listing |
Adv Sci (Weinh)
January 2025
DP Technology, Beijing, 100080, China.
Powder X-ray diffraction (PXRD) is a prevalent technique in materials characterization. While the analysis of PXRD often requires extensive human manual intervention, and most automated method only achieved at coarse-grained level. The more difficult and important task of fine-grained crystal structure prediction from PXRD remains unaddressed.
View Article and Find Full Text PDFInt J Pharm
January 2025
Institute of Energy and Process Engineering, ETH Zurich, 8092 Zurich, Switzerland. Electronic address:
Numerous commercially available biopharmaceuticals are frozen or freeze-dried in vials. The temperature at which ice nucleates and its distribution across vials in a batch is critical to the design of freezing and freeze-drying processes. Here we study experimentally how the level of particulate impurities - a key parameter in pharmaceutical manufacturing - affects the ice nucleation behavior.
View Article and Find Full Text PDFJ Hazard Mater
December 2024
School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China; Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China. Electronic address:
Understanding the behavior and fate of microplastics (MPs) in aquatic environment is crucial for assessing their potential risks. This study investigated the heteroaggregation behaviors of MPs with representative 2D nanosheets, MoS and graphene oxide (GO), under various conditions, focusing on the transport behavior of the resulting aggregates. It was found that the destabilization capabilities of 2D nanosheets are notably stronger than those of well-reported nanoparticles.
View Article and Find Full Text PDFChem Asian J
January 2025
Kanagawa University, Department of Chemistry, JAPAN.
Thermoelectric properties of undoped crystals of dibenzo[g,p]chrysene (DBC), deuterated DBC (DBC-d16), and 2,10-dimethyl-DBC (DBC-Me2) have been studied to obtain some insights into the relationship between the structural parameters of materials and the giant Seebeck effect. X-ray crystallography showed one-dimensional columnar packing with the interlayer distances (d) for DBC-d16, DBC, and DBC-Me2 were 3.78 Å, 3.
View Article and Find Full Text PDFAppl Radiat Isot
December 2024
Department of Metallurgy and Materials Engineering, Faculty of Engineering and Natural Sciences, Konya Technical University, Konya, Turkey.
The EuDyGeO, EuLaGeO and EuHoGeO powder were obtained through a solid-state reaction method via multistep firing of stoichiometric ratios of EuO, GeO, DyO, LaO and HoO in open atmosphere at temperatures from 800 to 1150 °C. The thermal behaviour, phase formation, SEM/EDX analysis, photoluminescence properties, Curie tempereture, dielectric and piezoelectric properties of the samples were investigated by TG/DTA, XRD, SEM, PL, TG/DTA, LCR-meter and d-meter, respectively. The germenates having triclinic crystal system have D→F, D→F, D→F, D→F transitions of Eu ions.
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