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1.
Artigo em Inglês | MEDLINE | ID: mdl-38709414

RESUMO

The introduction of biopolymers, which are sustainable and green materials, desegregated nature's water purification proficiency with science and technology, opens a new sustainable methodology in water reclamation. In order to introduce an efficacious adsorbent system for MB dye-toxic pollutant, adsorption, providing robust mechanical properties and facile processability, a facile system was introduced via electrospinning utilizing polylactic acid (PLA) and Ti3C2Tx, viz., PMX. The addition of 3 wt.% Ti3C2Tx led to a 3-fold substantial augmentation in the uptake capacity of the membrane from 197.28 to 307 mg/g when the adsorbate concentration was 100 ppm. The adsorption followed a PSO behavior, proposing that the rate-limiting stage is chemisorption and data best fitted to Freundlich isotherm, indicating heterogeneous adsorption sites and multi-layer adsorption. Further, biodegradability was studied by simulating natural environmental conditions where the nanofibers exhibited 42-64% degradation after 270 days. Based on the result with PLA, it is anticipated that the prepared fibrous system will introduce a new perspective as a potential candidate for MB removal from wastewater, opening new directions toward the research and development in wastewater treatment with electrospun biopolymer fibers using waste PLA.

2.
Sci Total Environ ; 919: 170469, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38311090

RESUMO

The COVID-19 pandemic created an unprecedented demand for PPE, with single-use face masks emerging as a critical tool in containing virus transmission. However, the extensive use and improper disposal of these single-use face masks, predominantly composed of non-biodegradable plastics, has exacerbated environmental challenges. This research presents an innovative method for mechanically upcycling PPEs used in medical sectors i.e. single use face masks. The study investigates a facile approach for reclamation of infection-free and pure polypropylene (PP) plastic from discarded single use face masks (W-PP) and blends it with various vegetable oil percentages (5, 10 and 20 %), resulting in a versatile material suitable for various applications. Melt flow index, rheological behaviour, DSC and FTIR were employed to investigate the effect of vegetable oil/radical initiator through chemical grafting on W-PP properties. The results demonstrate significant enhancements in the tensile strength and modulus of W-PP when blended with vegetable oil and a radical initiator. There was a marked increase in tensile strength (33 %) and strain (55 %) compared to untreated W-PP, rendering W-PP both robust and flexible. Furthermore, we employed this upcycled W-PP in the fabrication of glass fibre-reinforced composites, resulting in notable enhancements in both tensile strength and impact resistance. The upcycled W-PP demonstrates excellent potential for various applications, such as sheet forming and 3D printing, where the non-brittleness of plastics plays a pivotal role in manufacturing high-quality products. The cost-benefit analysis of this approach underscores the potential of upcycling PPE waste as a sustainable solution to mitigate plastic pollution and conserve valuable resources. The applications of this upcycled material span a wide range of industries, including automotive composites, packaging, and 3D printing.


Assuntos
Máscaras , Pandemias , Humanos , Análise Custo-Benefício , Equipamento de Proteção Individual , Óleos de Plantas , Polipropilenos , Plásticos
3.
Adv Mater ; 36(19): e2312474, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38252677

RESUMO

Nanocarbons are emerging at the forefront of nanoscience, with diverse carbon nanoforms emerging over the past two decades. Early cancer diagnosis and therapy, driven by advanced chemistry techniques, play a pivotal role in mitigating mortality rates associated with cancer. Nanocarbons, with an attractive combination of well-defined architectures, biocompatibility, and nanoscale dimension, offer an incredibly versatile platform for cancer imaging and therapy. This paper aims to review the underlying principles regarding the controllable synthesis, fluorescence origins, cellular toxicity, and surface functionalization routes of several classes of nanocarbons: carbon nanodots, nanodiamonds, carbon nanoonions, and carbon nanohorns. This review also highlights recent breakthroughs regarding the green synthesis of different nanocarbons from renewable sources. It also presents a comprehensive and unified overview of the latest cancer-related applications of nanocarbons and how they can be designed to interface with biological systems and work as cancer diagnostics and therapeutic tools. The commercial status for large-scale manufacturing of nanocarbons is also presented. Finally, it proposes future research opportunities aimed at engendering modifiable and high-performance nanocarbons for emerging applications across medical industries. This work is envisioned as a cornerstone to guide interdisciplinary teams in crafting fluorescent nanocarbons with tailored attributes that can revolutionize cancer diagnostics and therapy.


Assuntos
Corantes Fluorescentes , Neoplasias , Humanos , Neoplasias/diagnóstico por imagem , Neoplasias/tratamento farmacológico , Neoplasias/diagnóstico , Corantes Fluorescentes/química , Animais , Imagem Óptica , Nanopartículas/química , Carbono/química
4.
Int J Biol Macromol ; 261(Pt 1): 129647, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38281527

RESUMO

The limitation of conventional packaging in demonstrating accurate and real-time food expiration dates leads to food waste and foodborne diseases. Real-time food quality monitoring via intelligent packaging could be an effective solution to reduce food waste and foodborne illnesses. This review focuses on recent technological advances incorporated into food packaging for monitoring food spoilage, with a major focus on paper-based sensors and their combination with smartphone. This review paper offers a comprehensive exploration of advanced macromolecular technologies in biodegradable packaging, a general overview of paper-based probes and their incorporation into food packaging coupled with intelligent sensing mechanisms for monitoring food freshness. Given the escalating global concerns surrounding food waste, our manuscript serves as a pivotal resource, consolidating current research findings and highlighting the transformative potential of these innovative packaging solutions. We also highlight the current intelligent paper-based food freshness sensors and their various advantages and limitations. Examples of implementation of paper-based sensors/probes for food storage and their accuracy are presented. Finally, we examined how intelligent packaging can be an alternative to reduce food waste. Several technologies discussed here have good potential to be used in food packaging for real-time food monitoring, especially when combined with smartphone diagnosis.


Assuntos
Doenças Transmitidas por Alimentos , Eliminação de Resíduos , Humanos , Perda e Desperdício de Alimentos , Alimentos , Embalagem de Medicamentos , Embalagem de Alimentos
5.
RSC Adv ; 13(44): 30633-30642, 2023 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-37859776

RESUMO

Structural batteries (SBs) have gained attention due to their ability to provide energy storage and structural support in vehicles and airplanes, using carbon fibers (CFs) as their main component. However, the development of high-performance carbon fiber-based cathode materials for structural batteries is currently limited. To address this issue, this study proposes a cost-efficient and straightforward method for creating a high-performance structural lithium iron phosphate (LiFePO4) positive electrode by coating carbon fibers at mild temperatures and pressures. The resulting cathode demonstrated a high LiFePO4 loading (at least 74%) and a smooth coating, as confirmed by X-ray spectroscopy, scanning electron microscopy, and Raman spectroscopy. This structural cathode exhibited a capacity of 144 mA h g-1 and 108 mA h g-1 at 0.1 C and 1.0 C, respectively. Additionally, the LiFePO4 cathode displayed excellent electrochemical properties, with a capacity retention of 96.4% at 0.33 C and 81.2% at 1.0 C after 300 cycles. Overall, this study presents a promising approach for fabricating high-performance structural batteries with enhanced energy storage and structural capabilities.

6.
ACS Omega ; 8(21): 18449-18461, 2023 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-37273619

RESUMO

Nacreous architecture has a good combination of toughness and modulus, which can be mimicked at the micron to submicron level using 3D printing to resolve the demand in numerous applications such as automobile, aerospace, and protection equipment. The present study examines the fabrication of two nacre structures, a nacre columnar (NC) and a nacre sheet (NS), and a pristine structure via fused deposition modeling (FDM) and explores their mechanically superior stacking structure, mechanism of failure, crack propagation, and energy dissipation. The examination reveals that the nacre structure has significant mechanical properties compared to a neat sample. Additionally, NS has 112.098 J/m impact resistance (9.37% improvement), 803.415 MPa elastic modulus (11.23% improvement), and 1563 MPa flexural modulus (10.85% improvement), which are all higher than those of the NC arrangement.

7.
Sci Total Environ ; 863: 160896, 2023 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-36516923

RESUMO

The application of waste-derived highly efficient adsorbent for organic pollutants removal from water and wastewater is presented. Highly porous carbon beads with radially aligned macrochannels were prepared from asphaltene. Well-ordered inwardly aligned macrovoids favored solute diffusion and maximized the liquid accommodation capacity. A further N-doping could modulate the sorbent hydrophilicity leading to an outstanding absorption performance for a range of organic solvents and oily chemicals. N-doped carbon beads were effective sorbents of lopinavir (LNV) and ritonavir (RNV) from water and wastewater. The process of sorption was fast, and the highest removal was noted for RNV than LPV. N-doping favored LNV and RNV adsorption due to the increased porous structure of N-doped asphaltene beads. The chemisorption of both LPV and RTV was a rate-limiting step. The presence of co-pollutants in treated wastewater enhanced LPV and RNV removal and an up to 470 % increase was noted. The presence of LPV or RTV in distilled water was not toxic to Aliivibrio fischeri or even can stimulate their growth. However, after the adsorption process, the solution of RTV reduced its toxicity significantly and the final solution was not toxic. The opposite effect was noted for LPV. Given the repeatability, high removal performance, and cost-effectiveness of the asphaltene-based carbon microtubes when compared to other well-known sorbents such as carbon nanotubes, they demonstrated great potential as a low-cost and effective agent for long-life water filtration and wastewater treatment.

8.
J Hazard Mater ; 443(Pt A): 130168, 2023 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-36302289

RESUMO

Undesired discharge of various effluents directly into the aquatic ecosystem can adversely affect water quality, endangering aquatic and terrestrial flora and fauna. Therefore, the conceptual design and fabrication of a sustainable system for alleviating the harmful toxins that are discharged into the atmosphere and water bodies using a green sustainable approach is a fundamental standpoint. Adsorptive removal of toxins (∼99% removal efficacy) is one of the most attractive and facile approaches for cleaner technologies that remediate the environmental impacts and provide a safe operating space. Recently, the introduction of biopolymers for the adsorptive abstraction of toxins from water has received considerable attention due to their eclectic accessibility, biodegradability, biocompatibility, non-toxicity, and enhanced removal efficacy (∼ 80-90% for electrospun fibers). This review summarizes the recent literature on the biosorption of various toxins by biopolymers and the possible interaction between the adsorbent and adsorbate, providing an in-depth perspective of the adsorption mechanism. Most of the observed results are explained in terms of (1) biopolymers classification and application, (2) toxicity of various effluents, (3) biopolymers in wastewater treatment and their removal mechanism, and (4) regeneration, reuse, and biodegradation of the adsorbent biopolymer.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Poluentes Químicos da Água/análise , Ecossistema , Purificação da Água/métodos , Adsorção , Biopolímeros , Águas Residuárias
9.
ACS Appl Mater Interfaces ; 14(40): 45320-45332, 2022 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-36178739

RESUMO

In recent years, structural batteries have received great attention for future automotive application in which a load-bearing car panel is used as an energy storage. However, based on the current advances, achieving both high ionic conductivity and mechanical performance has remained a challenge. To address this challenge, this study introduces a cellulose nanocrystal (CNC) reinforced structural battery electrolyte (CSBE) consisting of CNC, triethylene glycol dimethyl ether (TriG) electrolyte containing a quasi-solid additive, e.g., cyclohexanedimethanol (CHDM), in a vinyl ester polymer. This green and renewable CSBE electrolyte system was in situ polymerized via reaction induced phase transition to form a high performance multidimensional channel electrolyte to be used in structural carbon fiber-based battery fabrication. The effect of various concentrations of CNC on the electrolyte ionic conductivity and mechanical properties was obtained in their relation to intermolecular interactions, interpreted by FTIR, Raman, Li NMR results. Compared to the neat SBE system, the optimized CSBE nanocomposite containing 2 wt % CNC shows a remarkable ionic conductivity of 1.1 × 10-3 S cm-1 at 30 °C, which reveals ∼300% improvement, alongside higher thermal stability. Based on the FTIR, Raman, Li NMR results, the content of CNC in the CSBE structure plays a crucial role not only in the formation of cellulose network skeleton but also in physical interaction with polymer matrix, providing an efficient Li+ pathway through the electrolyte matrix. The carbon fiber composite was fabricated by 2 wt % CNC reinforced SBE electrolyte to evaluate as a battery half-cell. The results demonstrated that by addition of 2 wt % CNC into SBE system, 7.6% and 33.9% improvements were achieved in specific capacity at 0.33 C and tensile strength, respectively, implying outstanding potential of ion conduction and mechanical load transfer between the carbon fibers and the electrolyte.

10.
Macromol Rapid Commun ; 43(11): e2200114, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35344626

RESUMO

Ti3 C2 Tx MXene (or "MXene" for simplicity) has gained noteworthy attention for its metal-like electrical conductivity and high electrochemical capacitance-a unique blend of properties attractive toward a wide range of applications such as energy storage, healthcare monitoring, and electromagnetic interference shielding. However, processing MXene architectures using conventional methods often deals with the presence of defects, voids, and isotropic flake arrangements, resulting in a trade-off in properties. Here, a sequential bridging (SB) strategy is reported to fabricate dense, freestanding MXene films of interconnected flakes with minimal defects, significantly enhancing its mechanical properties, specifically tensile strength (≈285 MPa) and breaking energy (≈16.1 MJ m-3 ), while retaining substantial values of electrical conductivity (≈3050 S cm-1 ) and electrochemical capacitance (≈920 F cm-3 ). This SB method first involves forming a cellulose nanocrystal-stitched MXene framework, followed by infiltration with structure-densifying calcium cations (Ca2+ ), resulting in tough and fatigue resistant films with anisotropic, evenly spaced, and strongly interconnected flakes - properties essential for developing high-performance energy-storage devices. It is anticipated that the knowledge gained in this work will be extended toward improving the robustness and retaining the electronic properties of 2D nanomaterial-based macroarchitectures.

11.
J Hazard Mater ; 426: 127822, 2022 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-34823952

RESUMO

Superwettable and chemically stable waste silk fabric and degummed silk were used in this study for treatment of oily wastewater and oil/solvent recovery. Silk functionalized with a nano-fluoro dispersion showed a superhydrophobic and oleophilic nature. The functionalized silk demonstrated superoleophilicity towards petroleum oils and organic solvents, and exhibited filtration efficiencies of more than 95%, and up to 70% till 25 re-usable cycles. Furthermore, the functionalized silk materials demonstrated high permeation flux of 584 L.m-2.h-1 (for Diesel) for continuous oil-water separation operation. The pH based study in highly acidic and alkaline mediums (pH from 1 to 13) showed excellent stability of nano-fluoro coated silk. Thermogravimetric analysis showed thermal stability up to 250 °C, and 400 °C, for functionalized waste silk, and degummed silk, respectively. FE-SEM analysis revealed randomly oriented spindle shaped nano particles anchored on the silk surface exhibiting hierarchical patterns, as required for the superhydrophobic Cassie-Baxter state. The rate absorption study showed close curve fitting for pseudo second order kinetics (R2 = 0.999), which indicated physical absorption process. BET analysis confirmed the porous nature, while the elemental XPS and EDX analysis confirmed strong bonding and uniform coating of fluoro nanoparticles on silk surface. The results demonstrated that nano-fluoro dispersion functionalized silk can be successfully employed for effective oil/solvent-water filtration, oil/solvent-spill cleanups, and treatment of oily wastewater for protection of water resources.


Assuntos
Petróleo , Águas Residuárias , Interações Hidrofóbicas e Hidrofílicas , Óleos , Seda , Solventes
12.
APL Mater ; 9(3): 031112, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33842101

RESUMO

The COVID-19 pandemic is the largest global public health outbreak in the 21st century so far. Based on World Health Organization reports, the main source of SARS-CoV-2 infection is transmission of droplets released when an infected person coughs, sneezes, or exhales. Viral particles can remain in the air and on the surfaces for a long time. These droplets are too heavy to float in air and rapidly fall down onto the surfaces. To minimize the risk of the infection, entire surrounding environment should be disinfected or neutralized regularly. Development of the antiviral coating for the surface of objects that are frequently used by the public could be a practical route to prevent the spread of the viral particles and inactivation of the transmission of the viruses. In this short review, the design of the antiviral coating to combat the spread of different viruses has been discussed and the technological attempts for minimizing the coronavirus outbreak have been highlighted.

13.
J Adv Res ; 34: 13-27, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-35024178

RESUMO

Introduction: Biochar utilization for adsorption seems to be the most cost-effective, easy/fast approach for pollutants removal from water and wastewater. Due to the high adsorption properties, magnetic biochar proved to be efficient in the sorption of heavy metals and nutrients. Although there are several studies on development of magnetic biochars, there is a lack of research on development of high-performance magnetic biochar from food waste for removal applications. Objectives: This study aimed at preparing new classes of magnetic biochar derived from tea waste (TBC) for removal of heavy metals (Ni2+, Co2+), and nutrients (NH4+ and PO43-) from water and effective fertilizer (source of NH4+ and PO43-). Methods: Standard carbonization process and ultrafast microwave have been used for fabrication of TBCs. The removal of nickel, cobalt as the representatives of heavy metals, and over-enriched nutrients (NH4+ and PO43-) from water were tested and the removal kinetics, mechanism, and the effect of pH, dissolved organic matter and ionic strength were studied. Simultaneously, possible fertilizing effect of TBC for controlled release of nutrients (NH4+ and PO43-) in soil was investigated. Results: Up to 147.84 mg g-1 of Ni2+ and 160.00 mg g-1 of Co2+ were adsorbed onto tested biochars. The process of co-adsorption was also efficient (at least 131.68 mg g-1 of Co2+ and 160.00 mg g-1 of Ni2+). The highest adsorbed amount of NH4+ was 49.43 mg g-1, and the highest amount of PO43- was 112.61 mg g-1. The increase of the solution ionic strength and the presence of natural organic matter affected both the amount of adsorbed Ni2++Co2+ and the reaction mechanism. Conclusions: The results revealed that magnetic nanoparticle impregnated onto tea biochar, can be a very promising alternative for wastewater treatment especially considering removal of heavy metals and nutrients and slow-release fertilizer to improve the composition of soil elements.


Assuntos
Carvão Vegetal , Eliminação de Resíduos , Matéria Orgânica Dissolvida , Alimentos , Fenômenos Magnéticos , Chá
14.
Adv Sci (Weinh) ; 7(13): 2000517, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32670767

RESUMO

Hierarchically porous piezoelectric polymer nanofibers are prepared through precise control over the thermodynamics and kinetics of liquid-liquid phase separation of nonsolvent (water) in poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) solution. Hierarchy is achieved by fabricating fibers with pores only on the surface of the fiber, or pores only inside the fiber with a closed surface, or pores that are homogeneously distributed in both the volume and surface of the nanofiber. For the fabrication of hierarchically porous nanofibers, guidelines are formulated. A detailed experimental and simulation study of the influence of different porosities on the electrical output of piezoelectric nanogenerators is presented. It is shown that bulk porosity significantly increases the power output of the comprising nanogenerator, whereas surface porosity deteriorates electrical performance. Finite element method simulations attribute the better performance to increased volumetric strain in bulk porous nanofibers.

15.
Sci Total Environ ; 718: 137317, 2020 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-32088483

RESUMO

In a circular economy model the way we use the textiles needs to change at a fundamental level. A circular economy is an alternative to a traditional economy (fabrication, use and dispose) in which we keep resources in a loop for as much time as possible, try to maintain their value while in use, and repurpose for generation of new products at the end of utilization. The value of the global fashion industry is 3000 Billion dollars that accounts for more than 2% of the world's Gross Domestic Product (GDP) (https://fashionunited.com/global-fashion-industry-statistics/). In the last two decades not only the textile industry has doubled the production but also an average global annual consumption of textiles has doubled from 7 to 13 kg per person and reached to the threshold of 100 million tonnes of textiles consumption. More than two thirds of the textile goes to landfill at the end of their use and just around 15% is recycled. Various scientific studies confirm that the disposal nature of fast fashion and throwaway culture is resulting in a serious environmental, health, social and economic concern. One of the global environmental challenges arising from micro-plastic and micro-textile waste entering into the oceans that can end up in fish and eventually food chain. Herein, through a systematic literature review, the significance of circular fashion and textile is highlighted and various approaches for reuse, recycle and repurposing of the textiles waste as well as disruptive scientific breakthroughs, innovations and strategies towards a circular textile economy have been discussed. Looking into the future, remarks have been made in regards to tackling the key challenges in recycling of textile materials in different stages of their manufacturing process.

16.
J Hazard Mater ; 389: 121823, 2020 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-31859169

RESUMO

Present study reports superhydrophobic-oleophilic, environment-friendly, & biodegradable silk material derived from Bombyx mori silkworm, for practical oil-water separation and oil recovery applications. In this study, raw silk fibers were degummed using water and Na2CO3 (at 100 °C), for removal of outer gummy sericin protein layer, which was confirmed using FTIR & FE-SEM analysis. The water & Na2CO3 degummed silk fibers showed superhydrophobicity with water contact angles (WCA) of 153° & 158°, respectively, demonstrating Wenzel & Cassi-Baxter states. Degummed silk fibers showed superoleophilicity (OCA∼0°) towards petroleum oils like Petrol, Diesel, & Engine oil. The water & Na2CO3 degummed silk fibers showed oil-water separation efficiencies of 95 % & 87.5 %, respectively. Both degummed silk fibers showed more than 50 % efficiency till 10 separation cycles. Further, raw & degummed silk fibers showed an environmental biocompatibility, by their biodegradation under in-house developed biotic de-compost culture consisting of biodegrading micro-organisms. Their analysis showed that biotic de-compost culture rendered biodegradation weight loss of 11 % and 18 %, respectively, in 35 days. Successive results showed that, degummed silk fibers can be effectively utilized for practical oil-water separation, and further, they can be environmentally biodegraded, thereby mitigating their waste generation and disposal problem.


Assuntos
Fibroínas/química , Petróleo/análise , Águas Residuárias/química , Poluição Química da Água/análise , Purificação da Água/métodos , Adsorção , Biodegradação Ambiental , Interações Hidrofóbicas e Hidrofílicas , Sericinas/química , Resistência à Tração , Molhabilidade
17.
Adv Sci (Weinh) ; 6(21): 1900762, 2019 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-31728275

RESUMO

For most carbon-based materials, hierarchical porous structure including well-defined macropores, mesopores, and micropores is commonly seen in 3D aerogels, monoliths, or some carbothermic natural biomass. However, because of the filiform character and long draw ratio, it is difficult to achieve such pore network as well as attain excellent mechanical performance in a 1D single carbon fiber system. To address this issue, an innovative hierarchical porous and hollow carbon textile (HPHCT) is developed via the "dynamic template (KOH, SiO2, and Al2O3) calcination" strategy. Unlike conventional one-step activated carbonized fiber simply with meso or micropores, the fabricated textile generates honeycomb-like macropores uniformly spreading on fiber surface. More importantly, the ultra-lightweight yet flexible HPHCT is mechanically robust, superior to ordinary carbonized one. In addition, it delivers high capacitance of maximum 220 F g-1 as well as keeping long term stability with 100% retention after 10 000 cycles as freestanding electrodes in supercapacitor. Meanwhile, the all-solid integrated symmetric HPHCT supercapacitors demonstrates its high potential in powering electronics for wearable energy storage application.

18.
Heliyon ; 5(10): e02698, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31687521

RESUMO

Carbon fibre composites offer considerable potential for mass reduction in automotive applications. However, raw material cost is one of the major factors that constraints its extensive use in this mass market. Here we report a systematic study that presents the cost contributors by considering the entire process chain of the carbon fibre manufacturing. The sensitivity analysis revealed that the final cost of Polyacrylonitrile (PAN) precursor and carbon fibres were strongly influenced by tow size. It was observed that a prompt decrease in the precursor and carbon fibre cost per kg for tow sizes from 3k to 12k, later this decrement was gradual and almost became stable above 50k. Moreover, with an increase in tow size from 3k to 50k, the contribution of the precursor on the final carbon fibre cost decreased from 76.6% to 49.6%. On the other hand, the contribution of the other factors increased with increase in the tow size, for instance, labour (9.86%-17.78%), Energy (2.49%-6.48%) and Depreciation (6.11%-11.01%). Nevertheless, precursor holds the major share in determining the final price of the carbon fibres.

19.
Nanomaterials (Basel) ; 9(10)2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31581528

RESUMO

The most known analogue of graphene, molybdenum disulfide (MoS2) nanosheet, has recently captured great interest because it can present properties beyond graphene in several high technological applications. Nonetheless, the lack of a feasible, sustainable, and scalable approach, in which synthesizing and functionalization of 2H-MoS2 nanosheets occur simultaneously, is still a challenge. Herein, a hydrothermal treatment has been utilised to reduce the effect of breaking mechanisms on the lateral size of produced nanosheets during the ball milling process. It was demonstrated that the hydrothermal pre-treatment led to the initial intercalation of an organic molecule such as 4,4'-diaminodiphenyl sulfone (DDS) within the stacked MoS2 sheets. Such a phenomenon can promote the horizontal shear forces and cause sliding and peeling mechanisms to be the dominated ones during low energy ball milling. Such combined methods can result in the production of 2H functionalized MoS2 nanosheets. The resultant few layers showed an average lateral dimension of more than 640 nm with the thickness as low as 6 nm and a surface area as high as 121.8 m2/g. These features of the synthesised MoS2 nanosheets, alongside their functional groups, can result in fully harnessing the reinforcing potential of MoS2 nanosheets for improvement of mechanical properties in different types of polymeric matrices.

20.
ACS Omega ; 4(6): 9720-9730, 2019 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-31460062

RESUMO

Nanocellulose, as a biobased versatile nanomaterial that can be derived with tailorable surface functionalities, dimensions, and morphologies, has considerable implications for modifying the rheology, mechanical reinforcement, and influencing the carbonization efficiency in the production of polyacrylonitrile (PAN)-based carbon fibers. Herein, we report the influence of three different nanocellulose types, varying in the derivatization method, source, and aspect ratio, on the mechanical properties and thermal transformations of solution-spun PAN/nanocellulose nanocomposite fibers into carbon fibers. The incorporation of 0.1 wt % nanocellulose into solution-spun PAN fibers led to a 7-19% increase in tensile modulus and 0-27% increase in tensile strength in the solution-spun fibers, compared to a control PAN fiber. These improvements varied depending on the nanocellulose type. After low-temperature carbonization at 1200 °C, improvements in the mechanical properties of the nanocellulose-reinforced carbon fibers, compared with a PAN fiber, were also observed. In contrast to the precursor fibers, the improvement % in the carbonized fibers was found to be dependent on the nanocellulose morphology and was linearly correlated with increasing aspect ratio of nanocellulose. For example, in carbon fibers with a cotton-derived low-aspect-ratio cellulose nanocrystal and spinifex-derived high-aspect-ratio CNC and nanofiber, up to 4, 87, and 172% improvements in tensile moduli were observed, respectively. Due to the processing methods used, the nanocellulose aspect ratio and crystallinity are inversely related, and as such, the increase in the carbon fiber mechanical properties was also related to a decrease in crystallinity of the nanocellulose reinforcers. Raman spectra and electron microscopy analysis suggest that mechanical improvement after carbonization is due to internal reinforcement by highly ordered regions surrounding the carbonized nanocellulose, within the turbostratic carbon fibers.

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