Experimental and theoretical methods were employed to investigate the ambient-pressure, metastable phase transition pathways for Mg2C, which was recovered after high-pressure synthesis. We demonstrate that at temperatures above 600 K isolated C(4-) anions within the Mg2C structure polymerize into longer-chain carbon polyanions, resulting in the formation of the α-Mg2C3 (Pnnm) structure, which is another local energy minimum for the carbon-magnesium system. Access to the thermodynamic ground state (decomposition into graphite) was achieved at temperatures above ∼1000 K. These results indicate that recoverable high-pressure materials can serve as useful high-energy precursors for ambient-pressure materials synthesis, and they show a novel mechanism for the formation of carbon chains from methanide structures.
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Int J Biol Macromol
January 2025
Key Laboratory of Intelligent Textile and Flexible Interconnection of Zhejiang Province, Zhejiang Sci-Tech University, Hangzhou 310018, China; Department of Chemical Engineering, Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada. Electronic address:
Both nanocellulose and graphene nanosheets serve as exceptional fillers for biopolymers. However, there are limited materials that effectively combine the properties of these two fillers in Poly (propylene carbonate) (PPC) to enhance their overall properties. This study presents a meticulous approach to producing graphitized nanocellulose (GCNC) with tailored rod-like (R-GCNC) and spheres-like (S-GCNC) under low-temperature and ambient-pressure conditions.
View Article and Find Full Text PDFNatl Sci Rev
November 2024
College of Chemistry, The Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials (MoE), National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610064, China.
Bio-based aerogels, which are poised as compelling thermal insulators, demand intricate synthesis procedures and have limited durability under harsh conditions. The integration of smart stimuli-response transitions in biomass aerogels holds promise as a solution, yet remains a challenge. Here, we introduce a pioneering strategy that employs reversible-gel-assisted ambient-pressure drying without organic solvents to craft multifunctional bio-based aerogels.
View Article and Find Full Text PDFNano Lett
November 2024
Department of Materials Science & Engineering, Iowa State University, Ames, Iowa 50011, United States.
Conventional polyol synthesis of silver nanowires has exclusively relied on polyvinylpyrrolidone (PVP), a nonbiodegradable polymer with no viable alternatives. The underlying reaction mechanism remains unclear. Herein, we discovered a new sustainable solution by employing biobased cellulose derivatives, including hydroxyethyl cellulose (HEC), as effective substitutes for PVP.
View Article and Find Full Text PDFSoft Matter
November 2024
Dipartimento di Ingegneria Chimica, dei Materiali e della Produzione Industriale, University of Naples Federico II, Naples, Italy.
The release of pressure from a high-pressure-stable polymer/gas solution is a common method for creating gas bubbles and forming foam with a typical polyhedral cell structure. We propose a new approach to control the foaming process by pausing the bubble growth at intermediate pressure before reaching ambient pressure. This allows us to control the growth of the bubbles and investigate various physical phenomena involved in polymer foaming, such as Ostwald ripening, bubble interactions, coalescence, and different bubble growth regimes.
View Article and Find Full Text PDFACS Appl Energy Mater
October 2024
Photon Science Institute, University of Manchester, Oxford Road, Manchester, M13 9PL, United Kingdom.
In recent years, hydrogels have been demonstrated as simple and cheap additives to improve the optical properties and material stability of organometal halide perovskites (OHPs), with most research centered on the use of hydrophilic, petrochemical-derived polymers. Here, we investigate the role of a peptide hydrogel in passivating defect sites and improving the stability of methylammonium lead iodide (MAPI, CHNHPbI) using closely controlled, X-ray photoelectron spectroscopy (XPS) techniques under realistic pressures. Optical measurements reveal that a reduction in the density of defect sites is achieved by incorporating peptide into the precursor solution during the conventional one-step MAPI fabrication approach.
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