Delamination In Materials Research Articles

Delamination of MXenes using bovine serum albumin

Delamination of two-dimensional materials is a requisite step for exploiting their unique properties. Herein, we report on the formation of stable colloidal solutions of Ti3C2 and Mo2Ti2C3 MXene nanosheets by the dispersion and electrostatic exfoliation of stacked multilayer MXenes in the presence of albumin. Delamination of multilayered MXenes into atomically thin nanosheets resulted in stable colloidal solutions with good stability due to the adsorption of albumin, which prevents re-aggregation of the few-layer nanosheets. Cascading centrifugation was used to produce monodisperse colloids. This study demonstrates a processing method that can be utilized to prepare MXenes for biomedical applications. Since protein adsorption onto nanomaterial surfaces plays a significant role in many fields, including medicine, biology, pharmaceuticals, and environmental engineering, albumin coated MXenes may find many applications.

A novel permeability perturbation testing method for delaminations in steel plates

ABSTRACT Delaminations have been detected based on the principle of ultrasonic thickness measurement. However, there are blind zones in the detection of surface delamination. Besides, the high-speed detection system is complicated. A novel permeability perturbation testing (PPT) method for the inspection of delaminations in ferromagnetic materials is proposed in this paper. When DC magnetisation is applied in the thickness direction of steel plate, the delamination in the plate will distort the internal magnetic field, leading to local permeability perturbation. This perturbation is transmitted to the surface layer of steel plate in the thickness direction. Using a differential-type eddy current transducer, internal delaminations are detected by measuring relative variation of surface permeability. The variation of permeability in the near surface of steel plate with the movement of delamination and the change of magnetisation state of the steel plate are obtained through finite element simulation. The feasibility of the above method is further verified through an experiment. This new method has the advantage in high-speed detection of delamination.

Reliability analysis and condition monitoring of SAC+ solder joints under high thermomechanical stress conditions using neuronal networks

The thermo-mechanical fatigue of different SAC+ solders is investigated using transient thermal analysis (TTA) and predicted using artificial neural networks (ANN). TTA measures the thermal impedance and allows detection of solder cracks and delamination of material interfaces. LEDs soldered to printed circuit boards using seven different solders were aged within passive air-to-air temperature shock tests with TTA measurements every 50 cycles with the increase of the thermal resistance as failure criterium. A SnAgCuSb solder showed the best performance improvement over the SAC305 reference under the test conditions. In addition to standard evaluation by the cumulative failure-curve and Weibull plot, new approaches for reliability assessment are investigated to assess the reliability of the solder joint of the individual LEDs. A hybrid approach to predict failures in the solder joints of the individual LEDs during accelerated stress testing is set-up which processes the TTA data using artificial neural networks with memory, specifically LSTM, where the memory allows full use of the measurement history. Two ANN approaches, regression and classification, are used. Both approaches are shown to be quite accurate. The greater information gained from the regression approach requires more processing using external knowledge of the problem requirements, whereas the categorical approach can be more directly implemented. The results demonstrate the advantages of integrated approaches for assessment of the remaining useful life of solder joints.

Stress induced delamination of suspended MoS2 in aqueous environments.

Applying hydrostatic pressure with suspended 2D material thin membranes allows probing the effects of lateral strain on the ion and fluid transport through nanopores. We demonstrate how both permanent and temporary delamination of 2D materials can be induced by pressure and potential differences between the membrane, causing a strong mechanosensitive modulation of ion transport. Our methodology is based on in situ measurements of ionic current and streaming modulation as the supporting membrane is indented or bulged with pressure. We demonstrate how indirect measurements of fluid transport through delaminated MoS2 membranes is achieved through monitoring streaming current and potential. This is combined with TEM images of 2D material membranes before and after aqueous measurements, showing temporary delamination during mechanical or electrical stress. The obtained results allow a better understanding of measurements with supported 2D materials, i.e. avoiding misinterpreting measured data, and could be used to probe how the electrical field and fluid flow at the nanoscale influence the adhesion of supported 2D materials.

Influence of spray distance on mechanical and tribological properties of HVOF sprayed WC-Co-Cr coatings

Abstract In this work, the tungsten carbide reinforcement in cobalt matrix (WC-Co-Cr) coatings was studied. The deposition process was carried out by high-velocity oxy-fuel spraying (HVOF). The study aimed to investigate the influence of one of the key process parameters, namely spray distance, on the coatings’ microstructure and phase composition, as well as their mechanical and tribological properties. The manufactured coatings were analysed by scanning electron microscopy, X-ray diffraction (XRD), instrumented indentation test, pull-off adhesion test and ball-on-disc method. The results revealed that selection of proper spray distance caused a high index of carbide retention (ICR) amounting to 0.95, which promoted higher hardness and better wear resistance. Instrumental microhardness was in the range of 14.2–14.8 GPa, whereas the Young modulus exhibited values from 336 GPa up to 342 GPa. The bond strength of deposited coatings was in the range of 55–65 MPa. Wear factor values were in the range of 73–81 × 10−7 mm3/(N · m) and the friction coefficient was about 0.4. The dominant wear mechanism is abrasion and adhesive mode supported by the fatigue-induced material delamination.

Fretting wear behaviour of machined layer of nickel-based superalloy produced by creep-feed profile grinding

Fretting wear has an adverse impact on the fatigue life of turbine blade roots. The current work is to comparatively investigate the fretting wear behaviour of the nickel-based superalloy surfaces produced by polishing and creep-feed profile grinding, respectively, in terms of surface/subsurface fretting damage, the friction coefficient, wear volume and wear rate. Experimental results show that the granulated tribolayer aggravates the workpiece wear, while the flat compacted tribolayer enhances the wear resistance ability of workpiece, irrespective of whether the workpiece is processed by polishing or grinding. However, the wear behaviors of tribolayers are different. For the polished surface, when the normal load exceeds 100 N, the main defects are crack, rupture, delamination and peeling of workpiece materials; the wear mechanism changes from severe oxidative wear to fatigue wear and abrasive wear when the loads increase from 50 to 180 N. As for the ground surface, the main wear mechanism is abrasive wear. Particularly, the ground surface possesses better wear-resistant ability than the polished surface because the former has the lower values in coefficient friction (0.23), wear volume (0.06 × 106 μm3) and wear rate (0.25 × 10−16 Pa−1). Finally, an illustration is given to characterize the evolution of wear debris on such nickel-based superalloy on the ground surface.

Investigation of the thermomechanical performance of hybrid polymer composite using micro bamboo powder and graphite flakes

AbstractThe current research project is dedicated to tackling the issue of fiber alignment and composite material delamination. Alkali treatment is performed to enhance the bamboo filler reinforced composite's mechanical performance as well as interfacial bonding strength. The hybrid composite is developed with varied bamboo powder content from 2.5 to 12.5 wt% and graphite nanoplatelets (GN) are reinforced in the polymer matrix. The hybrid composite is manufactured with bamboo powder approximately 65 μm sized and GN for electrical and electronics packaging, heat sink, conductive paste, light back cover for thermal management, automobile parts, and packaging goods. The developed material is investigated experimentally through the tensile test, modulus of elasticity, storage modulus, thermal conductivity, corrosion and tribological analysis. Results revealed that 5 and 7.5 wt% bamboo filler with 1 wt% GN gives the best property among others.

Breathing Parylene-Based Nanothin Artificial SEI for Highly-Stable Long Life Three-Dimensional Silicon Lithium-Ion Batteries

Here, we present on the application and characterization of parylene layers of nanometric thickness as a highly efficient artificial elastic SEI layer for three-dimensional nano-silicon anodes. The simple deposition process of the parylene layers creates an extremely conformal layer, even on the most complex three-dimensional substrate geometries and can be easily controlled down to thicknesses of below 30nm with excellent uniformity. The parylene nanothin layers are shown to be extremely stable chemically, electrochemically and mechanically, while notably allowing the free diffusion of Li-ions into the Si underlying active layer. The elasticity of the organic parylene layer plays a key role in the applicability of parylene to act as an efficient artificial SEI structure, as it was shown to be capable to withstand the dramatic natural "breathing" effect of the underlying silicon nanostructures, without interruption to the active material volumetric changes, while partially preventing and slowing the formation of a secondary SEI layer. Combined with our unique, novel substrate which demonstrates a simple catalyst-free growth of highly electrically conductive Si-stainless steel composite anodes with high loadings of silicon nanostructures and binder-free nature, remarkable electrochemical results can be achieved. Electrochemical characterization reveals that the Parylene-F VT-4 nanolayer is superior to other parylene types, exhibiting more than 450 cycles with 75% capacitiy retention vs Li metal anode. Importantly, the parylene layer does not allow delamination and cracking of active Si material, as evident from the 95.5% capacity retention after 400 cycles at low C-rate. The unique combination of the parylene artificial SEI layer and highly conductive substrates allow for high C-rates (>2C) to be achieved with significant capacity retention. The parylene layer is shown to dramatically improve the anode cycle life compared to bare silicon-based anodes, while not limiting the active material loading degree achievable. Most importantly, parylene is shown to fulfill all the required properties of artificial SEI, including impeccable chemical stability in organic solvents, elasticity and mechanical stability, high adhesion to the silicon under-layer, lowering the SEI formation, ionically conductive and electrically insulating and cost-effective, scalable and simple fabrication. The simplicity, applicability and control of parylene deposition, along with its vast improvement of stability of bare silicon anodes, make it an excellent candidate for future applications as an efficient artificial SEI layer for next-generation silicon anodes and other active materials of interest. Figure 1

Dynamic mode II interlaminar fracture toughness of electrically modified carbon/epoxy composites

This work investigates mode II delamination toughness of unidirectional carbon/epoxy laminates with enhanced electrical conductivity through different loading rates. The electrical modification was realized through interleaving a tough veil loaded with silver nanowires (AgNWs) into the laminate. A benchmarking against non-modified carbon/epoxy laminates was carried out to examine the influence of the modification of the material delamination toughness. End-notched flexure (ENF) specimens were subjected to loading rates ranging from quasi-static up to 5.5 m/s using servo-hydraulic load frame and modified Hopkinson bar apparatus. The strain energy release rate was determined by applying the compliance based beam method (CBBM), ruling out a necessity of the crack length measurement, generating complete R-curves. The findings demonstrated a notable increase, nearly 79%, on the critical strain energy release rate of the modified laminates, in comparison with that of the reference ones, carried out under the quasi-static loading condition. With respect to the influence of loading rate on mode II interlaminar fracture toughness values, the non-modified carbon/epoxy laminates demonstrated a marginal increase, whereas showing no notable effect on the interleaved ones.

Investigation of inhomogeneous degradation in large-format lithium-ion batteries

Large-format prismatic lithium-ion batteries (LIBs) with 52 Ah capacity and Verband Der Automobilindustrie (VDA) standard dimensions were cycled under a preloading force of 2.5 kN at 25 °C. When cycled, the LIBs exhibited a two-stage degradation behavior characterized by a first linear degradation stage and a second nonlinear degradation stage. The two-stage behavior which is also called rollover failure is investigated by post-mortem analysis. When the jelly roll was unfolded, lithium plating and delamination of cathode materials were found in the curved areas. From the scanning electron microscopy (SEM) images, the graphite particles in the curved areas were deformed and cracked. The LIB under a higher preloading force of 5.5 kN was found to have shorter cycle life, indicating mechanical force is one of the factors that lead to the rollover failure. The degradation mechanism was thoroughly illustrated by applying shift voltage-resistance voltage (SV-RV), differential voltage (DV) and electrochemical impedance spectroscopy (EIS) measurements. The SV-RV analysis suggests that lithium plating occurs after around 300 cycles. The shifting to low capacity and broadening of peaks in dV/dQ curves indicate that the second nonlinear degradation stage could be caused by combining loss of active materials (LAM) and loss of lithium inventory (LLI). In the nonlinear degradation stage, ohmic resistance (Rs) and charge transfer resistance (Rct) is dramatically increased as characterized by EIS measurement. The increased Rs and Rct further support the conclusion that LLI and LAM are the dominating degradation mechanism in the nonlinear degradation stage.

In vitro evaluation of delamination resistance of PEEK and CFR-PEEK.

Poly-ether-ether-ketone (PEEK) and carbon fiber reinforced PEEK as orthopedic implant materials exhibit excellent material properties. Although delamination of PEEK materials has been reported in knee joint wear research, the delamination resistance behavior remains unclear. In this study, the delamination resistance of PEEK materials was investigated; these materials were compared to ultra-high molecular weight polyethylene (UHMWPE). The results of a ball-on-flat type delamination test indicated that the PEEK materials underwent delamination considerably earlier than UHMWPE, and the contact area of the PEEK materials was smaller than that of UHMWPE. Moreover, the indentation modulus, hardness, and coefficient of friction were higher for PEEK materials than for UHMWPE. The reduced tendency of PEEK materials to undergo deformation to mitigate stress concentration at low conformity contact conditions contributed to their inferior delamination resistance compared to that of UHMWPE. The delamination resistance of the PEEK materials was equivalent to that of degraded UHMWPE, which highlights the risk of delamination of PEEK implants in a clinical context. Consequently, when using PEEK materials as an implant component loaded at a low conformity contact condition, the material selection and component design must be carefully considered. Overall, the results of this study can help guide the future development of PEEK-based implants.

Wear Behavior Analysis of Al2O3 Coatings Manufactured by APS and HVOF Spraying Processes Using Powder and Suspension Feedstocks

Thermally sprayed ceramic coatings are applied for the protection of surfaces that are exposed mainly to wear, high temperatures, and corrosion. In recent years, great interest has been garnered by spray processes with submicrometric and nanometric feedstock materials, due to the refinement of the structure and improved coating properties. This paper compares the microstructure and tribological properties of alumina coatings sprayed using conventional atmospheric plasma spraying (APS), and various methods that use finely grained suspension feedstocks, namely, suspension plasma spraying (SPS) and suspension high-velocity oxy-fuel spraying (S-HVOF). Furthermore, the suspension plasma-sprayed Al2O3 coatings have been deposited with radial (SPS) and axial (A-SPS) feedstock injection. The results showed that all suspension-based coatings demonstrated much better wear resistance than the powder-sprayed ones. S-HVOF and axial suspension plasma spraying (A-SPS) allowed for the deposition of the most dense and homogeneous coatings. Dense-structured coatings with low porosity (4 vol.%) and good cohesion to the metallic substrate, containing a high content of α–Al2O3 phase (56 vol.%) and a very low wear rate (0.2 ± 0.04 mm3 × 10−6/(N∙m)), were produced with the S-HVOF method. The wear mechanism of ceramic coatings included the adhesive wear mode supported by the fatigue-induced material delamination. Moreover, the presence of wear debris and tribofilm was confirmed. Finally, the coefficient of friction for the coatings was in the range between 0.44 and 0.68, with the highest values being recorded for APS sprayed coatings.

The Materials Science Foundation Supporting the Microfabrication of Reliable Polyimide-Metal Neuroelectronic Interfaces.

Thin-film polyimide-metal neuroelectronic interfaces hold the potential to alleviate many neurological disorders. However, their long-term reliability is challenged by an aggressive implant environment that causes delamination and degradation of critical materials, resulting in a degradation or complete loss of implant function. Herein, a rigorous and in-depth analysis is presented on the fabrication and modification of critical materials in these thin-film neural interfaces. Special attention is given to improving the interfacial adhesion between thin films and processing modifications to maximize device reliability. Fundamental material analyses are performed on the polyimide substrate and adhesion-promotion candidates, including amorphous silicon carbide (a-SiC:H), amorphous carbon, and silane coupling agents. Basic fabrication rules are identified to markedly improve polyimide self-adhesion, including optimizing the polyimide-cure profile and maximizing high-energy surface activation. In general, oxide-forming materials are identified as poor adhesive aids to polyimide without targeted modifications. Methods are identified to incorporate effective a-SiC:H interfacial layers to improve metal adherence to polyimide, in addition to examples of alloying between adjacent material layers that can impact the trace resistivity and long-term reliability of the thin-film interfaces. The provided rationale and consequences of key decisions made should promote more reproducible science using robust and reliable neuroelectronic technology.

Flexible ultraviolet detector with robust ZnO nanoparticle nanoassemblies on catechol‐functionalized polysiloxane nanofilms

AbstractAs a result of the vast Young's moduli difference between an inorganic semiconducting channel and flexible substrates, flexible optoelectronic devices readily lose their functionality through material delamination and local fracturing, which lead to short‐circuiting of devices. For this study, we synthesized a catechol‐containing polysiloxane (CFPS) adhesive and applied it to ZnO nanoparticle (NP) assembly on plastic substrates for flexible UV detector applications. The 30 nm thick CFPS adhesive can anchor 70 nm thick ZnO NPs strongly through a coordination bond, thereby forming an ultra‐stable ZnO NP channel layer. A peeling test of ZnO NP layer was conducted using transparent tape (Scotch®; 3 M Inc.). The ZnO NPs were firmly immobilized, reflecting the outstanding mechanical stability of CFPS adhesives. A UV detector also exhibited stable photo‐response performance even after a thousand iterations of bending with 3 mm curvature radii. The result indicates the polycyclosiloxane‐based flexible device as promising for wearable detector applications.

Comparison of rolling contact fatigue damage between railway wheels and twin-disc test specimens

Management of wheel-rail contact is of great importance for railways. It is essential to understand the tribology of railway materials to maximize productivity and reduce maintenance. Many studies on wear and rolling contact fatigue (RCF) were performed, ranging from field and full-scale experiments to small-scale tests, such as twin-disc. However, comparison between results found in these distinct approaches are few. Thus, RCF damage was compared between twin-disc specimens and wheels removed from field operation. Some aspects of RCF were remarkably similar, such as plastically deformed layer thickness, microhardness, crack angle and material delamination. However, cracks depth and length were 10–15 times larger in wheels. Finally, laboratory tests hardly simulate RCF in advanced stages and relevant environmental effects.

Graph theoretical design of biomimetic aramid nanofiber composites as insulation coatings for implantable bioelectronics

Creating an insulation material combining crack and delamination resistance, mechanical flexibility, strong adhesion, and biocompatibility is vital for implantable bioelectronic devices of all types. Here, we describe a nanocomposite material addressing these technological challenges that have been designed using blueprints from biomaterials that combine a similar set of properties. These composites are based on aramid nanofibers (ANFs), whose mechanical properties are complemented by the epoxy resins with strong adhesion to various surfaces. The nanoscale structure of the ANF/epoxy nanocomposite coating replicates the nanofibrous organization of human cartilage, which is known for its exceptional toughness and delamination resistance. The structural analogy between percolating networks of cartilage and ANF was demonstrated numerically using graph theory (GT) analysis. The match of multiple GT indexes indicated the near-identical organization pattern of cartilage and ANF/epoxy nanocomposite. When compared with the standard insulating material for bioelectronics, Parylene C, the ANF/epoxy nanocomposite exceeds its performance characteristics in respect to delamination resistance, interfacial adhesion, tissue biocompatibility, electrode cross-talk and inflammatory response. This study opens the possibility of GT-informed design of high-performance insulation materials suitable for different types of electronics for neural engineering and other biomedical applications. GT analysis also makes possible structural characterization of complex biological and biomimetic materials. While the design of the electronics for implantable devices has substantially advanced, the materials for their long-term insulation have not. Delamination of insulation materials constantly results in device failure. The essential problem of this field is finding a material that affords the combination of multiple contrarian properties that need to be resolved to afford future advances in this area. Here, we report a new nanocomposite material that combines durability, toughness, and flexibility, as well as excellent adhesion, biocompatibility, and low inflammatory response. This study opens the road for a large family of materials suitable for different types of implantable electronics for neural engineering and other biomedical applications.

2,2-Dimethyl-1,3-dioxane-4,6‑dione functionalized poly(ethylene oxide)-based polyurethanes as multi-functional binders for silicon anodes of lithium ion batteries

Chemically reactive groups (2,2-dimethyl-1,3-dioxane-4,6‑dione (Meldrum's acid, MA) and poly(ethylene oxide) (PEO) segments are incorporated to polyurethanes as binders of silicon anode for lithium ion batteries, aiming to address the volume change issue of the silicon anode in lithiation/delithiation cycles. The polymeric binder builds up multiple interaction to silicon surfaces, including hydrogen bonding between the urethane linkages of the bonder and silanol groups of silicon surfaces and covalent linkages through the addition reaction between ketene groups (generated from MA thermolysis reaction) and silanol groups of silicon surfaces. Self-dimerization of ketene groups also results in crosslinked structure of the binder. Both of the above-mentioned interaction and crosslinked structure contribute to stabilize the silicon anode materials. Moreover, the PEO segments facilitate the transportation of lithium ions and increase the ion conductivity of the anode. Consequently, the corresponding silicon anode is workable at a high C rate (0.8C) to demonstrate a specific capacity of approximately 1,785 mAh g − 1 and a capacity retention of 58% after a 600-cycle charge/discharge test. Morphological observation on the anode materials after a 300-cycle test indicates that the reactive PU binder could effectively depress cracks and interphase separation of the anode materials caused by the lithiation/delithiation-induced volume changes. The prepared binder also exhibits stabilization on the solid electrolyte interphase (SEI) layer and prevent anode material delamination. The results demonstrate a successful example of designs and preparation of multi-functional binders for silicon anodes.

High temperature tribological behaviour of additively manufactured tool material for applications in press hardening

In hot sheet metal forming, minimising material transfer and ensuring homogenous cooling of the workpiece are important for quality and productivity reasons. The development of additive manufacturing (AM) opens up possibilities for novel tooling concepts by tailoring the tool material (new chemistries, microstructure, and size/distribution of hard phases) and producing conformal cooling channels. Implementing surface functionality for improved tribological performance is another advantage of AM. Research pertaining to high temperature tribological behaviour of AM tool materials is, however, very limited.The aim of this work is to study the high temperature friction and wear behaviour of AM produced maraging steel and compare this to a conventional hot-work tool steel. The AM maraging steel was post-machined to different surface conditions (milled, ground and shot blasted).The tribological behaviour was evaluated using a hot-strip drawing tribometer and the counter surface was an Al–Si coated 22MnB5 steel. The temperatures of the Al–Si coated steel strips were 600 and 700 °C during the tribological tests.The results have shown that the friction behaviour of the maraging steel and the hot-work tool steel at 600 °C was stable and very similar. At 700 °C, the maraging steel showed more unstable friction and early failure of the tests due to high friction compared to the hot forming tool steel. This was associated with increased material transfer and embedment of FeAlSi intermetallics from the workpiece surface.The maraging steel experienced material removal and development of transfer layers composed of debris from both surfaces in contact. Comparable wear behaviour was observed at both temperatures, but its severity increased with temperature. The milled and ground surfaces showed similar wear mechanisms including ploughing and delamination of material, as well as embedment of FeAlSi particles. The shot blasted surface showed less build-up of transferred material but instead more deformation and folding of asperities leading to entrapment of FeAlSi particles in the near surface region.

Tailoring the thermomechanical behaviour of epoxy with the incorporation of bamboo and graphite filler

The present study is committed to overcome the problem associated with fiber orientation, delamination in composite material. Micro-sized bamboo particulate and graphite is selected as potential filler incorporation material in view of its potential application in thermal management in electronic, automobile parts, electronic packaging and consumer goods. Chemical treatment of natural micro filler is conducted to improve the binding strength among graphite and epoxy matrix. To develop the hybrid composite with varied bamboo filler 2.5 wt% to 12.5 wt% and graphite is incorporated in matrix material. Composite is developed by using NaOH treated micro bamboo particulate almost of 75 µm and graphite filler incorporated in the polymer matrix. The characteristics of specific ‘grade epoxy’ matrix are investigated through uniaxial tensile test, flexural test, dynamic mechanical analysis (DMA), thermal conductivity and wear performance. Results exhibited that with the addition of 0.2 wt% graphite filler (GF) in hybrid composite material enhanced the thermomechanical properties. The developed bamboo filler and graphite based hybrid composite will help to boost the utilization of waste natural filler for greener environment.

Synthesis of graphene: Potential carbon precursors and approaches

AbstractGraphene is an advanced carbon functional material with inherent unique properties that make it suitable for a wide range of applications. It can be synthesized through either the top–down approach involving delamination of graphitic materials or the bottom–up approach involving graphene assembly from smaller building units. Common top–down approaches are exfoliation and reduction while bottom–up approaches include chemical vapour deposition, epitaxial growth, and pyrolysis. A range of materials have been successfully used as precursors in various synthesis methods to derive graphene. This review analyses and discusses the suitability of conventional, plant- and animal-derived, chemical, and fossil precursors for graphene synthesis. Together with its associated technical feasibility and economic and environmental impacts, the quality of resultant graphene is critically assessed and discussed. After evaluating the parameters mentioned above, the most appropriate synthesis method for each precursor is identified. While graphite is currently the most common precursor for graphene synthesis, several other precursors have the potential to synthesize graphene of comparable, if not better, quality and yield. Thus, this review provides an overview and insights into identifying the potential of various carbon precursors for large-scale and commercial production of fit-for-purpose graphene for specific applications.