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1.
Int J Biol Macromol ; 276(Pt 2): 133906, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39019364

RESUMEN

This novel research addresses the critical need for sustainable and efficient materials, aiming to enhance the optical and thermoelectric properties of Aluminum doped Zinc Oxide (Al-doped ZnO) on cellulose fabric for diverse applications. At first stage, Cellulosic fabric of Al-doped ZnO were experimentally studied in detail with respect to varying levels of annealing temperature. Structural analysis unveiled structural evolution in hexagonal crystal formations with a reduction in particle size up to 27.5 % on average, with increased temperature. Further, Raman spectroscopy revealed the doping effects on the vibrational modes of ZnO, potentially due to alterations in lattice structure. The ZnO optical modes are found as E2 (low) = 110 cm-1 with observed phonon frequency in the Raman spectra of ZnO at A1 (TO) = 364 cm-1. Fourier transform infrared spectroscopy (FTIR) revealed the presence of characteristic stretching of developed material. Furthermore, the optical characters revealed a decrement of 43.22 % in bandgap values with increasing annealing temperature. The analysis of thermoelectric attributes documented that the prominent sample annealed at 300°C exhibited the maximum Seebeck coefficient and power factor of 2.1 × 10-3 µV/oC and 5.8 × 10-21 Wm-1 K-2, respectively. At second stage the optical characteristics of experimentally optimized sample were rigorously studied through the application of Material Studio software, while varying the doping ratio.


Asunto(s)
Celulosa , Textiles , Óxido de Zinc , Celulosa/química , Óxido de Zinc/química , Temperatura , Espectroscopía Infrarroja por Transformada de Fourier , Espectrometría Raman , Aluminio/química
2.
Int J Biol Macromol ; 267(Pt 2): 131441, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38583848

RESUMEN

The thermal stability of polyurethanes, known for its limitations, was addressed in this research by seeking improvement through the introduction of carbohydrate-based chain extenders. In this research paper, we systematically sought to improve the thermal resistance of polyurethanes by incorporating carboxymethyl cellulose and chitosan, representing a pioneering application of the mixture design approach in their preparation. In this synthesis, hydroxyl-terminated polybutadiene and isophorone diisocyanate (IPDI) were reacted to prepare -NCO terminated prepolymer, which was subsequently reacted with varying mole ratios of CMC and CSN to develop a series of five PU samples. The prepared PU samples were characterized using the Fourier-transformed infrared spectroscopic technique. Thermal pyrolysis of PU samples was examined using thermal gravimetric analysis (TGA). It was observed that, among all the samples, PUS-3 showed remarkable thermal stability over a wide temperature range. A comprehensive statistical analysis was conducted to substantiate the experimental findings. It was estimated that CMC and CSN significantly enhance the thermal stability of the samples when involved in an interaction fashion. The ANOVA Table for the mixture design demonstrates that over 90 % of the total variation in thermal stability is explained by the mixture model across a wide temperature range. Moreover, PSU-3 exhibited 4 % more thermal stability over a wide range of temperatures on average, as compared to contemporary samples.


Asunto(s)
Carboximetilcelulosa de Sodio , Quitosano , Poliuretanos , Quitosano/química , Carboximetilcelulosa de Sodio/química , Poliuretanos/química , Temperatura , Espectroscopía Infrarroja por Transformada de Fourier , Termogravimetría
3.
PLoS One ; 18(2): e0269566, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36758019

RESUMEN

This article fundamentally aims at the comparative study of thermo-mechanical characters of Gr/Ag and Gr/Cu nano-composites. For demonstration purposes, three dimensions that is, (1 0 0), (1 1 0) and (1 1 1), of the metals attached with single layer Graphene sheet are considered. The study is facilitated by the adaptation of the molecular dynamic simulations of the soft LAMMPS to mimic the broad range of experimental environment. The attributes of each structure and their orientations are elaborated over wide range of experimental states, encompassing temperature ranging from 300 K to 1500 K, to assess the melting behavior. The thermal and structural properties are explored by employing mean square displacement (MSD) and radial distribution function (RDF). Furthermore, the mechanical characters are elaborated along both arm-chair and zigzag directions. The findings are supported by producing relevant graphical displays of stress-strain curves and generating extravagant depictions of various dislocations with the application of visual molecular dynamics (VMD) tool. On the basis of intense and careful computational investigations, we witnessed that the Gr/Cu (1 1 1) orientation produced most profound melting characteristics along with distinctive strengthening and fracture mechanism. These outcomes are consistent in comparison of both Gr/Metals layered structures and also with respect to all considered metallic orientations. The findings are discussed thoroughly in a well-structured and synchronized fashion throughout the article.


Asunto(s)
Fracturas Óseas , Grafito , Humanos , Simulación de Dinámica Molecular , Aclimatación
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