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Preparation and Thermal Characterization of Hollow Graphite Fibers/Paraffin Composite Phase Change Material. COATINGS 2022. [DOI: 10.3390/coatings12020160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Paraffin is one of the most common and promising phase change materials to store and release thermal energy. The inadequacy of paraffin lies in its low thermal conductivity, which affects its further application on thermal energy storage. In this work, hollow fibers derived from pitch were spun. The graphitization (treated at 2773 K under argon atmosphere) induced the carbon atom arrangement and lattice order development, which endowed the hollow graphite fibers (HGFs) with good graphite structure. The HGFs applied as thermal additives into paraffin significantly improved its thermal conductivity. The high thermal conductivity of the HGFs/paraffin composite was achieved up to 2.50 W/(m·K) along the fiber axis, which displayed an over 680% enhancement as compared with that of the pure paraffin. The HGFs displayed significant improvement of the heat transfer rate and heat flow of paraffin, which indicated the promising potential application of the HGFs/paraffin PCM in thermal energy storage systems.
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Martínez-Higuera A, Rodríguez-Beas C, Villalobos-Noriega JMA, Arizmendi-Grijalva A, Ochoa-Sánchez C, Larios-Rodríguez E, Martínez-Soto JM, Rodríguez-León E, Ibarra-Zazueta C, Mora-Monroy R, Borbón-Nuñez HA, García-Galaz A, Candia-Plata MDC, López-Soto LF, Iñiguez-Palomares R. Hydrogel with silver nanoparticles synthesized by Mimosa tenuiflora for second-degree burns treatment. Sci Rep 2021; 11:11312. [PMID: 34050228 PMCID: PMC8163746 DOI: 10.1038/s41598-021-90763-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 05/07/2021] [Indexed: 02/04/2023] Open
Abstract
In this work we use Mimosa tenuiflora (MtE) extracts as reducing agents to synthesize silver nanoparticles (AgMt NPs) which were characterized by DPPH and Total Polyphenols Assays, UV-visible, X-ray diffractometer (XRD), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS) and Thermogravimetric analysis (TGA). AgMt NPs possess average sizes of 21 nm and fcc crystalline structure, it was also confirmed that the MtE is present in the AgMt NPs even after the cleaning protocol applied. Subsequently, carbopol hydrogels were made and the MtE and the synthesized AgMt NPs were dispersed in different gels (MtE-G and AgMt NPs-G, respectively) at 100 µg/g concentration. The gels were characterized by UV-Vis, IR, and rheology. Antimicrobial tests were performed using Staphylococcus aureus and Escherichia coli. Burn wound healing was evaluated in a second-degree burn injury on a Wistar rats model for 14 days and additional skin biopsies were examined with histopathological analysis. Gel with commercial silver nanoparticles (Ag NPs) was prepared and employed as a control on the biological assays. Hydrogel system containing silver nanoparticles synthesized with Mimosa tenuiflora (AgMt NPs-G) is a promising therapeutic strategy for burn wound healing, this due to bactericidal and anti-inflammatory effects, which promotes a more effective recovery (in percentage terms) by damaged area.
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Affiliation(s)
- Aaron Martínez-Higuera
- Department of Physics, Nanotechnology Graduate Program, University of Sonora, Rosales and Transversal, 83000, Hermosillo, Sonora, Mexico
| | - César Rodríguez-Beas
- Department of Physics, Nanotechnology Graduate Program, University of Sonora, Rosales and Transversal, 83000, Hermosillo, Sonora, Mexico
| | | | - Abraham Arizmendi-Grijalva
- Department of Physics, Nanotechnology Graduate Program, University of Sonora, Rosales and Transversal, 83000, Hermosillo, Sonora, Mexico
| | - Carlos Ochoa-Sánchez
- Department of Physics, Nanotechnology Graduate Program, University of Sonora, Rosales and Transversal, 83000, Hermosillo, Sonora, Mexico
| | - Eduardo Larios-Rodríguez
- Department of Chemical and Metallurgical Engineering, University of Sonora, Rosales and Transversal, 83000, Hermosillo, Sonora, Mexico
| | - Juan Manuel Martínez-Soto
- Department of Medicine and Health Science, University of Sonora, Rosales and Transversal, 83000, Hermosillo, Sonora, Mexico
| | - Ericka Rodríguez-León
- Department of Physics, Nanotechnology Graduate Program, University of Sonora, Rosales and Transversal, 83000, Hermosillo, Sonora, Mexico
| | - Cristina Ibarra-Zazueta
- Department of Agriculture and Livestock, University of Sonora, Road to Kino Bay km 20.5, Hermosillo, Sonora, Mexico
| | - Roberto Mora-Monroy
- Department of Physic Researching, University of Sonora, Rosales and Transversal, 83000, Hermosillo, Sonora, Mexico
| | - Hugo Alejandro Borbón-Nuñez
- CONACYT-Centro de Nanociencias Y Nanotecnología, UNAM, Km 107 Carretera Tijuana-Ensenada s/n, 22800, Ensenada, B.C. C.P, Mexico
| | - Alfonso García-Galaz
- Food Science Coordination, Research Center in Food & Development (CIAD), Road Gustavo Enrique Astiazarán Rosas, No. 46, Col. La Victoria, 83304, Hermosillo, Sonora, Mexico
| | - María Del Carmen Candia-Plata
- Department of Medicine and Health Science, University of Sonora, Rosales and Transversal, 83000, Hermosillo, Sonora, Mexico
| | - Luis Fernando López-Soto
- Department of Medicine and Health Science, University of Sonora, Rosales and Transversal, 83000, Hermosillo, Sonora, Mexico
| | - Ramón Iñiguez-Palomares
- Department of Physics, Nanotechnology Graduate Program, University of Sonora, Rosales and Transversal, 83000, Hermosillo, Sonora, Mexico.
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Design and Optimization of a Process for the Production of Methyl Methacrylate via Direct Methylation. Processes (Basel) 2019. [DOI: 10.3390/pr7060377] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Methyl methacrylate (MMA) plays a vital role in national productions with broad application. Herein, the production of MMA is realized by the improved eco-friendly direct methylation method using Aspen Plus software. Three novel kinds of energy-saving measures were proposed in this study, including the recycle streams of an aqueous solution, methacrolein (MAL), and methanol, the deployment of double-effect distillation instead of a normal one, and the design of a promising heat-exchange network. Moreover, MMA with a purity of 99.9% is obtained via the design of a MAL absorber column with an optimal stage number of 11 and a facile chloroform recovery process by using the RadFrac model. Thus, the proposed green process with energy-conservation superiority is the vital clue for developing MMA, and provides a reference for the production of MMA-ramifications with excellent prospects.
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