| 1. |
- Agrawal, Munmun, et al.
(författare)
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Global market trends of tantalum and recycling methods from Waste Tantalum Capacitors: A review
- 2021
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Ingår i: Sustainable Materials and Technologies. - : Elsevier BV. - 2214-9937. ; 29
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Forskningsöversikt (refereegranskat)abstract
- The rapid digitalization of the world, technological up-gradation, and shorten life cycle of electronic gadgets leading to the generation of an enormous amount of waste tantalum capacitors (WTCs) rich in tantalum every year. The need of the hour is to develop an effective way to recycle tantalum from these waste scraps considering the scarcity of tantalum, environmental impacts, resource and energy utilization, and lower recycling rates. In this paper, various existing methods of recovery of metallic tantalum from WTCs have been extensively reviewed. Processes have been examined in light of recovery efficiency, purity of the resultant product, process complexity, and limitations. The bottleneck in the recovery of tantalum from WTCs is the presence of tightly covered mold resin over the surface of the tantalum anode. Various researchers have recovered Ta with varying degrees of success. Pyrolysis, followed by chloride metallurgy, has been proven to be an effective technology on account of its high removal rate, resource and energy utilization, and lesser environmental impacts. This article also explores the global scenario of tantalum. Overall this review provides a foundation to understand the potential barrier and various opportunities associated with the recovery of tantalum from WTCs.
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| 2. |
- Asfaw, Habtom D., Dr. 1986-, et al.
(författare)
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Bio-derived hard carbon nanosheets with high rate sodium-ion storage characteristics
- 2022
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Ingår i: Sustainable Materials and Technologies. - : Elsevier. - 2214-9937. ; 32
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Tidskriftsartikel (refereegranskat)abstract
- Biomass is a sustainable precursor of hard carbons destined for use in sodium-ion batteries. This study explores the synthesis of hard carbon nanosheets (HCNS) from oxidized cork and impact of synthesis temperature on the hard carbon characteristics. An increase in the carbonization temperature from 1000 to 1500 °C generally leads to lower BET specific surface areas (~55 to 20 m2 g−1) and d002 interlayer spacing (~ 4.0 to 3.7 Å). The effect of synthesis temperature is reflected in the initial coulombic efficiency (iCE) which increases from 72% at 1000 °C to 88% at 1500 °C, as a result of the decrease in surface area, and structural defects in the hard carbon as verified using Raman scattering. The impact of cycling temperature (~25, 30 and 55 °C) on the rate capability and long-term cycling is investigated using high precision coulometry cycler. For a galvanostatic test at 20 mA g−1 and ~ 25 °C, a reversible capacity of 276 mAh g−1 is observed with an iCE of ~88%. Increasing cycling temperature enhances the rate performance, but slightly lowers the iCE (~86% at 30 °C and ~ 81% at 55 °C). At 20 mA g−1, the reversible capacities obtained at 30 °C and 55 °C are on average ~ 260 and ~ 270 mAh g−1, respectively. For constant-current constant-voltage (CCCV) tests conducted at 30 °C, reversible capacities ranging from 252 to 268, 247–252, and 237–242 mAh g−1 can be obtained at 10, 100, and 1000 mA g−1, respectively. The respective capacities obtained at 55 °C are about 272–290, 260–279, and 234–265 mAh g−1 at 10, 100 and 1000 mA g−1. The applicability of the HCNS electrodes is eventually evaluated in full-cells with Prussian white cathodes, for which a discharge capacity of 152 mAh g−1 is obtained with an iCE of ~90%.
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| 3. |
- Bifulco, Aurelio, et al.
(författare)
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Coffee waste-derived biochar as a flame retardant for epoxy nanocomposites
- 2024
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Ingår i: Sustainable Materials and Technologies. - : Elsevier. - 2214-9937. ; 41
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Tidskriftsartikel (refereegranskat)abstract
- Starting from spent coffee grounds, the use of coffee-derived biochar (CB) as a flame retardant (FR) additive was explored following a waste-to-wealth approach. CB was employed alone and in combination with ammonium polyphosphate (APP) and a ternary (Si-Ti-Mg) mixed oxide to enhance the thermal, fire, and mechanical performances of a bisphenol A diglycidyl ether (DGEBA)-based epoxy resin modified with (3-aminopropyl)-triethoxysilane (APTES) and cured with a cycloaliphatic amine hardener. The presence of silicon-modified epoxy chains guaranteed the uniform distribution of CB throughout the resin. The combined FR action of fillers (CB, APP, and Si-Ti-Mg oxide) and the acidic characteristics of hybrid epoxy moieties enabled the achievement of a no dripping UL 94-V-0 classification for epoxy resin containing 20 wt% CB and 1 wt% of phosphorus loading, significantly increasing the flexural modulus (by ∼15%). Although it is not self-extinguishing, compared to pristine resin, the silicon-modified epoxy nanocomposite filled only with CB exhibited a remarkable decrease in the peak of heat release rate (pHRR) (by ∼65%) and a beneficial smoke suppressant effect with a notable decrease (∼11%) in the total smoke production. Cone calorimetry tests, pyrolysis combustion flow calorimetry analysis, and microscopy measurements helped to outline the combined mode of action of CB, APP, and Si-Ti-Mg oxide in the flame retardation of the hybrid epoxy resin, highlighting a strong FR action in the condensed phase, with the formation of a stable aromatic ceramic char, as well as the smoke suppressant character due to the basic nature of the ternary metal oxide and the ability of porous biochar to adsorb the generated gases.
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| 4. |
- Das, Sujit, et al.
(författare)
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Vehicle lightweighting energy use impacts in U.S. light-duty vehicle fleet
- 2016
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Ingår i: Sustainable Materials and Technologies. - : Elsevier BV. - 2214-9937. ; 8, s. 5-13
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Tidskriftsartikel (refereegranskat)abstract
- In this article, we estimate the potential energy benefits of lightweighting the light-duty vehicle fleet from both vehicle manufacturing and use perspectives using plausible lightweight vehicle designs involving several alternative lightweight materials, low- and high-end estimates of vehicle manufacturing energy, conventional and alternative powertrains, and two different market penetration scenarios for alternative powertrain light-duty vehicles at the fleet level. Cumulative life cycle energy savings (through 2050) across the nine material scenarios based on the conventional powertrain in the U.S. vehicle fleet range from - 29 to 94 billion GJ, with the greatest savings achieved by multi-material vehicles that select different lightweight materials to meet specific design purposes. Lightweighting alternative-powertrain vehicles could produce significant energy savings in the U.S. vehicle fleet, although their improved powertrain efficiencies lessen the energy savings opportunities for lightweighting. A maximum level of cumulative energy savings of lightweighting the U.S. light-duty vehicle through 2050 is estimated to be 66.1billion GJ under the conventional-vehicle dominated business-as-usual penetration scenario. (C) 2016 Elsevier B.V. All rights reserved.
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| 5. |
- Feng, Zhaoxuan, et al.
(författare)
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Carbon dot/polymer nanocomposites : From green synthesis to energy, environmental and biomedical applications
- 2021
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Ingår i: Sustainable Materials and Technologies. - : Elsevier BV. - 2214-9937. ; 29
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Tidskriftsartikel (refereegranskat)abstract
- Carbon dots (CDs), a novel family of multifunctional carbon-nanomaterials, has the potential to revolutionize several important fields supporting the transformation to sustainable bioeconomy. CDs are characterized by attractive properties such as tunable optoelectronic and fluorescence properties, low toxicity, good biocompatibility, bioactivity and superior water solubility. Diverse methods and precursors have been applied for the synthesis of CDs. The possibility to scale-up the synthesis of CDs by employing Green Chemistry principles is a current research hotspot and a prerequisite for large-scale production and applications. Incorporation of CDs into polymer matrices, is another emerging research area with wide potential application range. This approach endows additional desirable functions and enables easy handling and reuse. This review summarizes recent progress regarding the green synthesis of CDs, the fundamental strategies for the construction of CD/polymer nanocomposites and the state-of-art applications of the CD/polymer nanocomposites in the realm of energy storage, environment and biomedicine. Finally, the outlook including challenges and future potential of CDs and CD/polymer composites are discussed.
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| 6. |
- Hong Duc, Pham, et al.
(författare)
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Spent graphite from end-of-life Li-ion batteries as a potential electrode for aluminium ion battery
- 2020
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Ingår i: Sustainable Materials and Technologies. - : Elsevier BV. - 2214-9937.
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Tidskriftsartikel (refereegranskat)abstract
- Graphite is central in almost all commercial Li-ion batteries (LIBs) and possesses attractive physical and chemical properties such as good ionic conductivity and layered graphitic structure. In this communication, we have demonstrated the recycling of graphite from end-of-life LIBs and the re-purposing of the recovered material for positive electrodes in next-generation aluminium-ion-batteries (AIBs). The recovered graphite possesses enlarged interlayer spacing which is shown to effectively boost Al-ion insertion/de-insertion during the charge/discharge processes. Excellent Al-ion storage performance is achieved with the capacity reaching 124 mAh g−1 at 50 mA g−1. The material retained a capacity of 55 mAh g−1 even after the applied current was increased to 500 mA g−1, showing its capability to deliver high rate performance. The charge/discharge cycling further revealed that the graphite retains 81% of its initial capacity even after 6700 cycles at a high rate of 300 mA g−1. This excellent aluminium ion storage performance makes the recovered graphite a promising positive electrode material, providing a possible solution for the recycling of huge amounts of LIB scrap. At the same time, this material aids the development of alternative sustainable battery technology, as an alternative to LIBs.
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| 7. |
- Kahoush, May, 1985-, et al.
(författare)
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Towards sustainable textile sector: Fractionation and separation of cotton/ polyester fibers from blended textile waste
- 2022
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Ingår i: Sustainable Materials and Technologies. - : Elsevier. - 2214-9937.
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Tidskriftsartikel (refereegranskat)abstract
- Textiles made of blended cotton/polyester fibers have a huge share of the markets nowadays. The desirable properties of these blends made them a popular choice for both producers and consumers. However, at the end of life, this blended textile waste is often being disposed of in landfills in many parts of the world, since the fibers are hard to be fractionated and/or separated from each other and sorted according to their type, which hinders their recyclability and re-introduction to the supply chain. A significant loss of resources and big environmental impacts are only few consequences of these practices. In this article, we highlight the state of the art of fractionation and separation of cotton/polyester blended textile waste and the methods used in literature, which could be classified into mechanical, chemical and biological approaches. Additionally, we critically discuss the challenges facing these processes and their scaling-up, providing insights on how to overcome these challenges and the new initiatives in this regard, in order to contribute to the circularity and sustainability of the textile sector.
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| 8. |
- Kulkarni, Rohan Ajit, et al.
(författare)
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Experimental studies of dynamic compression of cellulose pulp fibers
- 2023
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Ingår i: Sustainable Materials and Technologies. - : Elsevier BV. - 2214-9937. ; 38
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Tidskriftsartikel (refereegranskat)abstract
- The ability to control the structure of the wood-pulp fiber cell wall is an attractive means to obtain increased accessibility to the fiber interior, providing routes for functionalization of the fibers that support further processing and novel material concepts, e.g. improved degree of polymerization, nanofiltration as demonstrated in previous studies. It has been proposed that dynamic compression and decompression of the cellulose pulp fibers in the wet state make it possible to modify the cell wall significantly. We hypothesize that hydrostatic pressure exerted on fibers fully submerged in water will increase the accessibility of the fiber wall by penetrating the fiber through weak spots in the cell wall. To pursue this, we have developed an experimental facility that can subject wet cellulose pulp samples to a pressure pulse -10 ms long and with a peak pressure of -300 MPa. The experiment is thus specifically designed to elucidate the effect of a rapid high-pressure pulse passing through the cellulose sample and enables studies of changes in structural properties over different size ranges. Different characterization techniques, including Scanning electron microscopy, X-ray diffraction, and wide- and small-angle X-ray scattering, have been used to evaluate the material exposed to pulsed pressure. The mechanism of pressure build-up is estimated computationally to complement the results. Key findings from the experiments consider a decrease in crystallinity and changes in the surface morphology of the cellulose sample.
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| 9. |
- Li, Ziyu, et al.
(författare)
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Sustainable choices of alloying element for aluminium for thermal conductivity in circular manufacturing
- 2024
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Ingår i: Sustainable Materials and Technologies. - : Elsevier. - 2214-9937. ; 40
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Tidskriftsartikel (refereegranskat)abstract
- Electrification is a keyword for many industries today, and thermal management is essential. This paper aims to review the sustainability perspective and analyse the need for thermal conductivity. A model for thermal conductivity is developed for as-cast and heat-treated states to be used as a basis for a sustainability impact index to allow quantitative decisions on sustainable alloying for heat transfer solution alloy development and selection. In the analysis, it was necessary to consider microstructural features for a satisfactory description of the thermal conductivity measured from a set of Al-Si-based alloys in the as-cast and heat-treated states. An environmental impact index was developed for the alloying elements to gauge the effectiveness of different alloying elements, including the environmental impact. An effort to include the microstructural effects was made. Due to the low thermal conductivity of the matrix phase in the as-cast state, the eutectic regions provide a positive contribution to the correction factor developed. The heat-treated stat microstructure seems to lack importance in the ranges of Si additions used in the current study.
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| 10. |
- Mansouri, Moufida, 1988, et al.
(författare)
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Waste of batteries management: Synthesis of magnetocaloric manganite compound from the REEs mixture generated during hydrometallurgical processing of NiMH batteries
- 2021
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Ingår i: Sustainable Materials and Technologies. - : Elsevier BV. - 2214-9937. ; 28
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Tidskriftsartikel (refereegranskat)abstract
- In the present study, rare earth elements (REEs, i.e., La, Ce, Nd, and Pr) were hydrometallurgically recovered in oxalate form with presence of very low concentration of Co, Al, Zn and Ni from solution after processing of spent Nickel metal hydride (Ni-MH) batteries. The recovered mixture was used as alternative source in the synthesis of magnetocaloric materials. In this study, a manganite sample with general formula ABO3 was selected to be prepared since it is relatively easy to synthesize and is tuneable by adjustment of the doping concentration. The conventional solid-state reaction method was used to prepare an orthorhombic structure of manganite with presence of REE2O3 and MnO2 as secondary phases reported from x-ray pattern at room temperature. The thermomagnetic measurements showed a PM to FM transition at 184 K in a 0.01 T magnetic field that shifts to 194 K by increasing the magnetic field to 1.8 T. The magnetocaloric properties were determined by calculating the isothermal entropy change and directly measuring the adiabatic temperature change. A reversible magnetocaloric effect was observed.
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