The thermal stability of PVC with 1 wt % of spherical porous nanosilica, prepared by roll milling at processing time varied from 1 to 20 min, was investigated by means of visual color changes, Congo red, and thermogravimetric tests (TGA and DTG), as a function of rolling time and composition of PVC matrix. The melt flow rate (MFR) measurements were realized to identify the degradation-induced changes of processing properties. A high level of gelation of the PVC matrix for all samples was verified by DSC (differential scanning calorimetry). It was found that the addition of porous nanosilica to absorb a certain volume of HCl, produced by dehydrochlorination reaction, leads to an improvement of thermal stability, an effect observed in a form of minor color changes of the samples, lower evolution of gas hydrogen chloride, and slight changes of the MFR value. It was demonstrated that the TGA measurements are not sufficiently sensible to detect the degradation of PVC at the processing conditions, i.e., at the temperature equal to 220 °C and below this temperature.
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http://dx.doi.org/10.3390/polym13132057 | DOI Listing |
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January 2025
School of Materials Science and Engineering, Wuhan University of Technology, Wuhan, 430070, China.
2D perovskite has demonstrated great potential for application in photovoltaic devices due to the tunable energy bands, suppressed ion migration, and high stability. However, 2D perovskite solar cells (PSCs) display suboptimal efficiency in comparison to 3D perovskite solar cells, which can be attributed to the quantum confinement and dielectric confinement effects resulting from the intercalation of organic spacer cations into the perovskite lattice. This review starts with the fundamental structural characteristics, optoelectronic properties, and carrier transport dynamics of 2D PSCs, followed by the discussion of approaches to improve the photovoltaic performance of 2D PSCs, including the manipulation of crystal orientation, phase distribution, pure phase, organic layer, and device engineering.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Humboldt-Universitat zu Berlin, Department of Chemistry, Brook-Taylor-Str. 2, 12489, Berlin, GERMANY.
Multifunctional ortho-quinones are required for the formation of thiol-catechol-connectivities (TCC) but can be delicate to handle. We present the electrochemical oxidation of the dipeptide DiDOPA, achieving up to 92% conversion efficiency of the catechols to ortho-quinones. Graphite and stainless steel could be employed as cost-efficient electrodes.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Jieyang Branch of Chemistry and Chemical Engineering Guangdong Laboratory, Jieyang 515200, China.
Optical physical unclonable functions (PUFs) are gaining attention as a robust security solution for identification in the expanding Internet of Things (IoT). To enhance the security and functionality of PUFs, integrating multiple optical responses─such as fluorescence and structural color─into a single system is essential. These diverse optical properties enable multilevel authentication, where different layers of security can be verified under varying light conditions, greatly reducing the risk of counterfeiting.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Advanced Catalysis Research Group, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
Polymers with rigid three-dimensional architectures have attracted significant attention due to their high rigidity and intrinsic microporosity. Here, we report the synthesis of a new class of rigid stepladder polymers featuring unique spirodihydroquinoline skeletons. Under the catalysis of a half-sandwich scandium catalyst, quinoline compounds bearing both an aryl substituent (e.
View Article and Find Full Text PDFJ Agric Food Chem
January 2025
College of Biological and Food Engineering, Huanghuai University, Zhumadian 463000, China.
The thermostability and catalytic activity of GH11 xylanase XynASP from JOP 1030-1 were improved by systematically engineering the cord region. Ultimately, mutant DSM4 was developed through iterative combinations of mutations. Compared to the wild-type XynASP, DSM4 showed a 130.
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