Modern society faces serious energy challenges, including the depletion of fossil fuels, environmental degradation, and global climate change. These pressing issues underscore the urgent need for sustainable energy storage and conversion technologies. In this context, carbon foam (CF) functionalized with ZnO nanorods (NRs) shows significant promise. To fabricate the carbon foam, a polyurethane (PU) foam template was used along with phenolic resin as the carbon source. The structure was stabilized by oxidation and then sintered at 1000 degrees C under a nitrogen atmosphere. ZnO NRs were subsequently grown on the CF using an in situ hydrothermal method, with loading concentrations ranging from 0 to 10 wt%. The structural and morphological characteristics of the ZnO NRs-functionalized CFs were analysed using XRD, SEM, and Raman spectroscopy. The SEM results revealed that ZnO were uniformly distributed across the CF surface. The electrochemical characteristics of binder-free electrodes based on ZnO NRs-functionalized CFs were systematically examined using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge-discharge (GCD) measurements. In a three-electrode system, the CF electrode functionalized with 10 wt% ZnO NRs exhibited a remarkable specific capacitance of 360 F g-1 at a scan rate of 5 mV s-1. Furthermore, an asymmetric supercapacitor device was assembled using the 10 wt% ZnO NRs-functionalized CF as the positive electrode and pristine CF as the negative electrode (denoted as CF-ZnO-10//CF). This device demonstrated excellent electrochemical performance, delivering a specific capacitance of 272 F g-1 at a current density of 0.5 A g-1, together with an energy density of 38 Wh kg-1 and a power density of 125 W kg-1. These results confirm the strong potential of ZnO NRs functionalized CF as a high-performance, binder-free electrode material for next-generation supercapacitor applications.

The aim of this study is to explore the effect of in-situ heat treatment on flow stress behavior, thereby eliminating the need for traditional heat treatment methods, thus reducing costs associated with equipment, time, and energy consumption. In the present study, thermo-mechanical behavior of an ultra-high specific strength AlSi10Mg/ graphene composites were studied. The composites were prepared with 0.0, 0.1 and 0.2 wt% Graphene in AlSi10Mg matrix using selective laser melting (SLM). The AlSi10Mg/Graphene composites were processed using two different preparation methods: single scanning and in-situ heat treatment (double scanning), to control the mechanical properties in as-built condition. The analytical techniques such as FESEM, EBSD, Raman, TEM and Micro-CT used to evaluate the grain structure, graphene distribution, various phases and porosity present in the composite processed through single scanned and in-situ heat treatment. The uniaxial tensile tests were carried out at different quasi-static strain rates (0.01-10 s-1) and at varying temperatures (25, 150, 250 and 350 degrees C). The results demonstrate that in-situ heat-treated samples exhibit superior thermomechanical performance compared to single-scanned counterparts at both ambient and elevated temperatures, irrespective of composition. Among the compositions, 0.1 wt% graphene shows optimal performance for a given scanning strategy. A modified Johnson-Cook (JC) model and artificial neural network (ANN) were developed using the experimental parameters of the AlSi10Mg/Graphene composites.

The modern electronics industry needs lightweight, porous materials with high-performance electromagnetic interference (EMI) shielding effectiveness (SE) and effective thermal management. This study proposes a straightforward electrochemical technique to produce lightweight silver-plated (Ag-plated) graphene-modified carbon foams (Gr@CFs) with good thermal conductivity and outstanding EMI shielding performance. Initially, Gr@CFs were synthesized via a sacrificial template method utilizing phenolic resin as a carbon precursor and graphene nanoplatelets (GNPs) as fillers, followed by carbonization at 1000 degrees C. Subsequently, the synthesized Gr@CFs experienced electroplating with silver (Ag) for varying durations ranging from 1 to 10 minutes. The Ag electroplating contributed to high EMI SE and endowed the Gr@CF with commendable electrical, thermal, and mechanical properties. The resultant Gr@CF with Ag plated for 10 minutes (Gr@CF-Ag10) possesses a remarkable combination of attributes: a high electrical conductivity of 180 S/cm, thermal conductivity of 6.0 W/ m & sdot;K, and excellent EMI SE of 73.5 dB at X-band, along with enhanced compressive strength of 6.5 MPa. Moreover, the fabricated Ag-plated Gr@CFs exhibit outstanding properties that render them well-suited for application in electronic devices requiring EMI shielding and effective thermal management.

The rapid increase in the electrification and automation of systems and products has led to the accumulation of electromagnetic radiation in the environment, resulting in electromagnetic interference (EMI). This interference harms living organisms and contributes to numerous electronic devices' malfunction and premature failure. Another significant global concern is the accumulation of industrial, agricultural, and biological waste (including water, air, and soil pollution), which poses critical risks to humans, animals, and the environment. This review aims to bridge these issues by critically discussing the use of waste materials for EMI shielding. Specifically, it provides an overview of conventional EMI shields and the challenges associated with their industrial scalability. The article explores potential solutions to these challenges and EMI shields' treatment and fabrication processes, incorporating various wastes. It also reports on the effectiveness of these waste-incorporated shields in EMI shielding. Finally, this review discusses the mechanism of EMI shielding and seeks to inspire and guide the scientific community to focus on the utilization of critical wastes and promote their effective use in technologically advanced applications.

Flexible energy storage devices have been the focus of much research and development as potential sources of energy for portable electronic devices. However, designing an innovative electrode structure that is cost-efficient, sustainable, and resource-efficient poses a significant challenge to the advancement of next-generation flexible-energy storage materials. Flyash, as an industrial waste, can be used as a potential electrode material because of its low cost and the presence of various metal oxides, especially silicon-based materials. Using a low-cost and binder-free vacuum filtration method, we present a facile method for forming a very stable porous architecture of flyash and multiwalled carbon nanotubes (MWCNTs). Here, the performances of flyash/MWCNT paper anodes prepared via acid-reflux and simple stirring methods are compared to determine the influence of both methods on the electrochemical properties of the anode. When using a current density of 0.1 A/g for up to 300 cycles, the acid-refluxed and flyash blended MWCNTs composite paper anodes exhibit a specific capacity of 290 mAh/g and 272 mAh/g, respectively, with over 98% coulombic efficiency. The highly porous and interconnected MWCNTs conducting network makes it easier for Li+ ions to penetrate and come into direct contact with the metal oxides found in flyash. As a result, the composite paper shows a high specific capacity that holds steady over extended cycles and impressive rate capabilities for Li storage.

The rapid development of electronics and instrumentation in recent years has raised increasing concerns about electromagnetic interference (EMI). To address this issue, the present study investigates the potential of carbon foam for EMI shielding applications. The aim is to enhance the EMI shielding effectiveness of carbon foam by integrating three distinct types of magnetic oxide (MO) nanoparticles (NPs). Graphene-incorporated carbon foam (Gr@CF) was primarily synthesized by impregnating phenolic resin and 2 wt% of graphene into polyurethane (PU) foam, then stabilization and carbonization at 1000 degrees C in a nitrogen atmosphere. To further enhance the EMI shielding properties of the carbon foam, graphene-decorated MO-NPs (Gr@MO-NPs), specifically NiO, Co3O4, and Fe3O4, were individually incorporated. The addition of these Gr@MO-NPs resulted in a significant improvement in the EMI shielding performance. Among the various combinations tested, the carbon foam reinforced with graphene-decorated Fe3O4 NPs (Gr@Fe3O4-CF) exhibited an outstanding total EMI shielding effectiveness (SET) of 86.6 dB, a high absorption efficiency (SEA) of 83.1 dB, and a low reflection efficiency (SER) of 3.5 dB. The remarkable EMI shielding absorption was attributed to the increased number of interfaces, defects, and dipole polarization within the foam, which facilitated the absorption and scattering of electromagnetic waves, enhancing the overall shielding performance.

The rapid development of electronics and instrumentation in recent years has raised increasing concerns about electromagnetic interference (EMI). To address this issue, the present study investigates the potential of carbon foam for EMI shielding applications. The aim is to enhance the EMI shielding effectiveness of carbon foam by integrating three distinct types of magnetic oxide (MO) nanoparticles (NPs). Graphene-incorporated carbon foam (Gr@CF) was primarily synthesized by impregnating phenolic resin and 2 wt% of graphene into polyurethane (PU) foam, then stabilization and carbonization at 1000°C in a nitrogen atmosphere. To further enhance the EMI shielding properties of the carbon foam, graphene-decorated MO-NPs (Gr@MO-NPs), specifically NiO, Co₃O₄, and Fe₃O₄, were individually incorporated. The addition of these Gr@MO-NPs resulted in a significant improvement in the EMI shielding performance. Among the various combinations tested, the carbon foam reinforced with graphene-decorated Fe₃O₄ NPs (Gr@Fe₃O₄-CF) exhibited an outstanding total EMI shielding effectiveness (SET) of 86.6 dB, a high absorption efficiency (SEA) of 83.1 dB, and a low reflection efficiency (SER) of 3.5 dB. The remarkable EMI shielding absorption was attributed to the increased number of interfaces, defects, and dipole polarization within the foam, which facilitated the absorption and scattering of electromagnetic waves, enhancing the overall shielding performance.

Friction and wear pose significant challenges in moving mechanical systems. Despite efforts to address these challenges with MAX phase materials, many of these materials lack effective lubrication and wear protection under ambient conditions. Here, we developed a composite coating that addresses these challenges through a combination of materials chemistry and engineering. This coating, composed of polydopamine-functionalized Ti3AlC2 MAX (F-MAX) and multilayer graphene (MGr), known as F-MAX + MGr, demonstrated exceptional tribological performance. At its best composition, the F-MAX + MGr composite coating reduced the friction at sliding interfaces by 82 % and decreased the wear on the counterpart ball by 99.76 % compared to bare surfaces. Importantly, its tribological performance surpassed that of pristine MAX, F-MAX, and MGr coatings. This improvement is attributed to the synergistic lubricating effect of the inherently low shear strengths of Ti3AlC2 MAX and MGr, the chemical properties of PDA, and the occurrence of incommensurate contacts at the interfaces. This work pioneers slippery and wear-resistant surfaces via a combination of chemical modification and materials engineering, with implications for both fundamental science and technological advancement.

Lightweight Ni-Ti alloy foam has received immense attention as a promising material for sensors, actuators, dampers, biomedical implants, and energy absorption applications due to their outstanding properties including low density, high surface area, corrosion resistance and excellent mechanical strength. In the present study, we developed Ni (50)-Ti (50) alloy foams with varying porosities using NaCl as a space holder. The cold compacted mixture of NiTi alloy powder, NaCl granules, and 2 wt% polyvinyl alcohol (PVA) solutions are mixed uniformly in a globe box for 8 hrs. Sintering is carried out in two stages: firstly, at 900 oC for 2 hrs and then at 1100 oC for two hrs. During sintering, NaCl gets melted and removed from the foams. The Ni-Ti alloy foams exhibit an excellent compressive strength of 48 MPa at a relative density (ρrd) of 0.45. It also provides higher plateau stress, greater strain hardening effect, and larger strain recovery. Thus, the lightweight high strength Ni-Ti alloy foam is a promising material for bone implants and energy absorption applications.

Understanding how sp2 carbons of different dimensionality engineer the shape memory polymer is crucial for fundamental science and developing next-generation technologies. Further, with modernization, widespread adoption of rechargeable lithium-ion batteries, as well as hotter, drier weather attributed to climate change, has indirectly led to a globally increasing trend of fire-related accidents. To prevent such accidents from causing large-scale destruction and casualties, the rapid detection of a fire event is extremely important. In this work, we have developed mechanically robust shape memory polyurethane (PU) composites containing graphitic-carbon fillers that exhibit good thermo-responsiveness. Reinforcement of the PU matrix by three types of graphitic-carbon fillers, namely 3D graphite, 2D multilayer graphene, and 1D multiwall carbon nanotubes, yielded 36–47

Energy losses, premature failure, and environmental degradation are the adverse impacts of the friction at sliding interfaces. Two-dimensional (2D) materials have recently attracted immense interest as solid lubricants. Here we develop a novel ternary nanocomposite overcoat comprising multi-layer graphene (MGr), MoS2 and multi-walled carbon nanotubes (CNT) which entangle each other, generate ensembles of trio, alter the sliding interfaces and thereby exceptionally reduce the friction (80%-85 %) and wear of diverse surfaces including metals (stainless steel (SS) 304, SS316L, mild steel (MS), Al-composite), ceramics (glass and Al2O3+TiC composite), and semi-conductor (silicon). Extensive spectroscopic and microscopic characterizations are performed to elucidate the fundamental mechanisms for friction and wear reduction. The comprehensive investigation clearly confirms that the tribological efficacy of our ternary nanocomposite overcoat surpasses the monolithic and binary nano -composite overcoats made of same materials. This discovery opens new avenues to control sliding interfaces with nanocomposites of 1D/2D materials, and can transform many moving mechanical technologies.

In recent years, there has been extensive research on graphene and its derivatives, driven by their remarkable physicochemical and functional properties. Various forms of graphene, such as multi-layer graphene, graphene oxide, and graphene quantum dots, have shown immense potential to revolutionize multiple technologies. This review critically examines the synthesis and applications of graphene and related materials. In the synthesis section, we explore methods ranging from top-down techniques, which involve breaking down larger structures into graphene layers, to bottom-up approaches, where graphene is built up from smaller constituents. In the application segment, we comprehensively discuss the diverse uses of graphene and its derivatives. This includes their roles in electronic applications, energy storage systems, tribological applications, healthcare technologies, water desalination processes, and mechanical applications. By exploring various applications, we aim to highlight the wide-spread applications of graphene-based materials and their composites in shaping the future of multiple technologies.

The current study focused on the investigation of the microstructural and compressive properties of Al-SiCMWCNT hybrid composite foams after the implementation of heat treatment. The samples were prepared with varying weight percentages of SiC and MWCNTs, with fixed porosity 86 % (relative density = 0.14). Initially, samples were subjected to solutionizing at 480 degrees C for 10h, followed by rapid water quenching. Subsequently, artificial aging was conducted by applying three different temperatures (150 degrees C, 180 degrees C, and 220 degrees C) for varying durations, ranging from 2 to 10h. The results revealed that significant improvement in mechanical properties and maximum peak compressive stress and microhardness were achieved between 6 and 8h and 8 and 10h, at the aging temperatures of 220 degrees C and 180 degrees C respectively. However, in the case of aging at 150 degrees C, mechanical properties also increased but at a slow rate, but no clear peak values were observed even after 10h of aging. It was observed that in case of HCF (both MWCNTs and SiC added as reinforcement) the plateau stress increased up to 30 to 40 %, whereas in case of AF, CF1, and CF2 foams the properties improved by 20 to 30 %. Also, by utilizing the established Gibson model, the plateau stresses were predicted and validated with experimental results.

The present work is focused on the decoration of nickel (Ni) and iron (Fe) nanoparticles on carbon fibers and these decorated fibers were reinforced in carbon foam. The foam was developed via the sacrificial template method followed by carbonization at 1000 degrees C. The structural, morphological, electrical, mechanical, and electromagnetic interference (EMI) shielding effectiveness (SE) of the fabricated composite foam is investigated. The EMI shielding of composite foams was measured in X-band (8.2-12.4GHz). The overall EMI SE of the received carbon foam (CF) was found to be 25.70 dB at 8.2 GHz; this value was then enhanced to 35.3 dB upon incorporation of carbon fiber in the carbon foam (C-CF). Further, the highest EMI SE of 62.3 dB was achieved in Fe nanoparticles decorated carbon fiber composite foam (Fe@C-CF). It is observed that Fe@C-CF exhibits an absorption component (SEA) of 58.5 dB (-94 %) and a reflection component of 3.8 dB (-6.0 %) only. Also, the Fe@C-CF showed the highest value of the specific EMI SE (778.25 dB cm(2) gm(-1)). The enhancement in EMI SE of composite foam can be ascribed to the occurrence of dielectric, magnetic, and interfacial polarization. So the developed lightweight composite foam demonstrated excellent EM wave absorption capability along with good mechanical and environmental sustainability.

While several coatings exist today to achieve tribological support on practical surfaces, the hunt for easily deployable yet tribological-efficient coatings still continues to fulfill the demand for commercial contact-sliding systems. Solution-based 2D/layered material coatings can be promising in this regard but many uncertainties remain to persist. Here we explored the tribological characteristics of solution-processed monolithic tungsten disulfide (WS2) and multilayer-graphene (mGR) coatings and simultaneously developed a new breed of WS2_mGR composite coating on stainless steel (SS) substrates. We discovered that monolithic WS2 coating (1mg/ml) is tribologically inefficient even at its higher concentration (up to 5mg/ml). The WS2_mGR composite coating demonstrated a remarkable reduction in friction and wear, with a 59% reduction in coefficient of friction (COF) compared to the Bare SS. Additionally, it demonstrated a 57% and 31% reduction in COF with respect to monolithic WS2 and mGR coatings, respectively, both prepared with the same concentration (1mg/ml). Further, we also discovered that at higher concentrations (5mg/ml) the monolithic mGR coating attains the lowest and most stable friction and high wear resistance over a longer period of time, even without the need for intermittent supply of lubricants during contact sliding.

In this study, carbon foams with high oxidative resistance were fabricated by employing a powder metallurgy route using semi-coke as a carbon precursor and ammonium bicarbonate as a pore-forming agent. The boric acid was used as an oxidative inhibitor. The effect of boric acid coating on the surface of carbon foam was extensively analyzed and compared with pure carbon foam. The oxidation resistance of boric acid-coated carbon foam (CF70BA) demonstrated very good thermal stability at 650 degrees C in the air for a period of 3 h, along with good compressive strength as compared to pure carbon foam. The resultant boric acid-coated carbon foam exhibit a high electrical conductivity of 437 S/cm and high thermal conductivity of 9.5 W/m.K. All the results revealed that this approach established a new simple and affordable concept for the development of lightweight carbon material with high oxidation resistance performance.

Friction and wear, which originate as a consequence of contact sliding, remain critical concerns. In many systems, friction causes 20-30% wastage of energy, while wear leads to premature failure of systems. Oxidation/corrosion is another major concern that limits the functionality and durability of components. Here, employing experiments and atomistic simulations, we demonstrate that single-layer graphene (SLG) adequately reduces the friction and wear of a metal and provides excellent oxidation protection. But beyond certain initial contact cycles, its coefficient of friction (COF) continuously increases from similar to 0.15 with progressing sliding cycles. In contrast, multilayer graphene (MGR) always maintains low friction (COF <= 0.1) and achieves relatively better wear resistance. Nevertheless, atomic thickness and realized good tribological and oxidation protection properties still make SLG a crucial candidate for many systems with constraint overcoat thickness such as magnetic storage devices and micro-/nano-electromechanical systems. The tribological properties of SLG and MGR are also compared with solution-based graphite coatings and plasma-grown diamond-like carbon coating. Through spectroscopic and microscopic characterizations, along with atomistic simulations and hypothetical models, we discover and present the friction and wear mechanisms of these tribo-systems. This work uncovers the critical sliding behavior of carbon-based systems for advancing and enabling sustainable moving mechanical technologies.

Organic light emitting diodes (OLEDs) are highly propitious display devices owing to their compelling properties, including ultrathin configuration, good flexibility, low-cost and low-temperature fabrication process. These OLEDs are vital for a plethora of wearable smart electronics, namely, foldable mobile phones, touchscreens, wafer-thin displays, antennas, curved and pliable solid-state lightning appliances, etc. Contingent upon their conductivity and transmittance, thin films incorporating transparent conductive oxide (TCO) (e.g., indium doped tin oxide, ITO) are quite often incorporated in optoelectronic devices. To overcome the cost limitation and flexibility issues associated with ITO, several studies are undertaken to discover novel transparent conductive electrodes. One such elucidation is the use of dielectric/metal/dielectric heterostructures as transparent electrodes, which exhibit excellent resilience, transparency and conductivity. Furthermore, they can be fabricated at ambient temperature using a simple thermal evaporation technique under vacuum. In this chapter, examples of these components for flexible OLEDs are discussed.

Fully open interconnected Al-foam having different PPI (Pores per inch) was fabricated through the novel template method. The morphology of the open-cell Aluminium foam (OCAF) (strut, pore, and cell size) can be easily tailored with this method. Three different PPI (10, 20, and 30) Al-foams were fabricated through the template method, and show the effect of PPIs' on their microstructure, thermal, electrical, and mechanical properties in detail. With different PPI of the foam, the porosity lies in the range of 85-94%. Through experiments, it was found that with the increase in PPI, the density of the foam gets increases. Complete openness and uniformity in terms of the pore, strut size, and porosity throughout the samples has been easily achieved with this method, which is very difficult with previously reported methods. As the PPI of the foam changes, the properties (electrical, thermal, and mechanical) also change. According to the requirement, one can easily tailor the properties by changing the PPI of the foam. Experimentally evaluated properties were also compared with the theoretically calculated values. The open-cell aluminium foam of 30 PPI (OCAF-30) having RD-0.14 shows electrical conductivity- 0.68 x 106 S/m, thermal conductivity- 6.43 W/m.K, and compressive strength of 0.65 MPa. This study helps the research community to fabricate OCAF according to their requirement with desired thermal, electrical, and mechanical properties for the application of heat transfer, electrocatalysis, and others.