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In the present scenario, biodiesel is a very highly renewable fuel and an excellent alternative to diesel. It is nontoxic, having high flash point and tremendous performance. But, the main drawbacks are poor atomization and incomplete combustion which could be overcome by incorporating additives and catalysts. The blends that we have used in our study are B20, B40, B60, B80 and B100 of which the optimum performance from tests was the B20 biodiesel. To further improve its performance, Graphene quantum dots (GQD) nanoparticles (100ppm) were added and the performance tests were carried out under varying loads from 0.5 kW to 3.5 kW. It was found that the HC, CO and NOX emissions reduced by 13.87%, 32.31% and 13% respectively and the efficiency increased by almost 3.5%, with the addition of GQD. [ABSTRACT FROM AUTHOR]

Electrochemical exfoliation of graphite method is one of the simple methods being developed in recent years to produce graphene. The aims in this work is further investigation to know the effect of using solenoid in the electrochemical exfoliation of graphite reactor to optimize production graphene by characterization the graphene products with XRD and RAMAN. Using solenoid can increase the weight of the graphene formed because the solenoid acts as an induction heater for accelerating the reaction rate of graphene formation. The result of this work are using solenoid at the reactor can increase up to 100% mass of graphene, and composite graphite phenol formaldehyde is a alternatif to be an anode for synthesis graphene with electrochemical exfoliation method. The result from the XRD patter is using solenoid at the reactor for synthesis graphene with electrochemical exfoliation process does not change the structure of graphene. There is a peak around 2700 cm−1 at raman spectra that indicated our product is graphene. [ABSTRACT FROM AUTHOR]

Graphite is an allotrope of carbon that occurs naturally. The structure is comprised of multiple layers of carbon atoms that are organized in a hexagonal lattice and are interconnected by relatively weak van der Waals forces. Graphite exhibits favorable electrical conductivity characteristics, demonstrating enhanced efficiency in conducting electricity along its layers as opposed to that perpendicular to the layers. This restriction influences the efficiency of the device within certain electrical and electronic applications. To address these challenges, a range of exfoliation techniques have been employed to achieve the production of graphene with a limited number of layers, typically ranging from single to a few layers. In this study, a straightforward and cost-effective method known as Scotch-Tape Microexfoliation was employed to produce graphene successfully. Optical images were captured to document various iterations of exfoliation. Notably, an increase in the number of iterations yielded a corresponding increase in film transparency, indicating the formation of a monolayer of graphene. Furthermore, the presence of defects in graphene was identified through the observation of the peak corresponding to the D-band in Raman spectroscopy. [ABSTRACT FROM AUTHOR]

Solid polymer electrolyte (SPE) has been emerging in the high-performance and have played important roles for the past few years and are promising materials for electrochemical devices applications. Methylcellulose was chosen as a primary host as it conducts relatively low conductivity besides biodegradable, environmentally friendly and essential commercial cellulose that has been used in many industrial applications. This study is conducted to investigate the morphology of membrane using Methylcellulose (MC) as host, doping with potassium hydroxide (KOH), polyethylene glycol (PEG) as plasticizer and graphene. The properties of MC with the additive on the structure and performances of the membrane was studied. The obtained membrane was prepared via the casting technique method and was characterized by scanning electron microscopy (SEM) and X-ray Diffraction (XRD). XRD pattern shows the crystalline structure shifted to amorphous nature of polymer electrolyte (PE) when adding the PEG onto the membrane. The presence of PE has potential application in electrochemical devices based on the results obtained. [ABSTRACT FROM AUTHOR]

Bacterial cellulose (BC) is synthesized from extract of pineapple peel and Acetobacter xylinum as fermentation bacteria. This study aims to investigate the influence of graphene concentration on the morphology and crystalinity in bacterial nanocellulose (BNC) nanocomposites. To obtain bacterial nanocellulose (BNC), the previously manufactured pellicle BC was homogenized using a high-speed blender and a high-pressure homogenizer (HPH). Bacterial nanocellulose was combined with different concentrations of graphene (0.25, 0.5, and 1%), and then put into an ultrasonic homogenizer. Then, BNC-graphene solution was poured into a glass mold laminated with aluminium foil, and it was dried in an oven for 14 hours, 80°C. Scanning electron microscopy (SEM) was used to observe the morphology of nanocomposites membrane. X-Ray Diffraction is used to investigate the crystallinity of nanocomposites membrane. The structure of BNC-graphene nanocomposites membrane become more compact, according to the synthesized results. A few peaks at 2θ of 14.5°, 16.6°, 22.7° are seen in the XRD analysis, as well as a graphene diffraction pattern peak at 2θ of 13.7°. Nanocomposites membrane's crystallinity was reduced after graphene was added when compared to nanocomposites membrane without graphene. [ABSTRACT FROM AUTHOR]

In the present paper, Graphene Field Effect Transistor model is studied. Firstly, a 5nm thick poly-silicon film is deposited and Graphene structure is generated. Graphene, with carrier mobility at 10,000cm2/V-s is the channel material. The output and transfer curves are drawn to plot characteristics. Pristine Graphene is treated as a semi-metal with zero band gap. The lesser band gap, causes a relatively low ION/IOFF as compared to the Silicon transistor, therefore in digital, GFET is still lagging behind Silicon BJT. High mobility is more suited for RF applications. Therefore, the maximum cut-off frequency (fT) and maximum oscillation frequency (fmax) are taken into consideration as the FOMs' parameters in the current article. [ABSTRACT FROM AUTHOR]

As the world's population is growing, the demand of drinkable water is increasing, especially in developing coutries. Life on Earth would not be possible without the water that sustains all of its other essential needs. Solar energy plays vital role for many applications such as cooking, water heating, drying of agricultural products, water distillation etc. In this study, improved sun-oriented stills with black paint coated with hybrid nanomaterial are compared without using nanomaterial with black paint. The solar still's absorber plate and walls are coated with a commercial black paint that contains the hybrid nanomaterial. Coated absorbers are used in the solar still, which makes use of reduced grapheme oxide/Cupric oxide nanoparticles. The characterization of graphene/cupric oxide with black paint coating was done to analyse the performance of the solar still. It was identified and analysed the areas of the solar-powered stills where energy was lost. The modified solar stills have faster dissipation and higher exergy compared to regular ones. As a result, the modified still has higher exergy and energy efficiency than older models. Additionally, a brief discussion of the influence of various limits on the efficacy of sunlight-based stills is also introduced. Reduced graphene and cupric oxide/water blends have a daily energy productivity of 44.18%, whereas the old-style has just 30.17% [ABSTRACT FROM AUTHOR]

In the present investigation we performed density functional theory (DFT) calculations to study adsorption and binding energies, density of states (DOS) for pristine graphene, Hafnium (Hf) decorated graphene and hydrogen molecule (1H2−6H2) adsorbed on Hf-decorated graphene as well. We found adsorption energy in negative range -221.524 Ry for pristine graphene, after decorating Hf atom adsorption energy found -345.891 Ry. When we successively increase the hydrogen molecules (1H2−6H2) the adsorption energy decreases gradually, it ranging from (-348.197 Ry to -358.99 Ry). The binding energy per H2 molecule also decreases from 2.306 to 0.377 eV. The evaluated Fermi energies of studied system found in the range 1.089 eV to 3.928 eV. The successive increase in Fermi energy confirms the hydrogen molecules (1H2-6H2) have sufficient surface area of Hf decorated graphene. Our investigation reveals that Hf decorated graphene could be a promising material to store H2 molecules on a Hafnium (Hf) decorated graphene system. [ABSTRACT FROM AUTHOR]

In the present study, the influence of structural damping on impulse response of sandwich plates with FG-porous graphene reinforced core is investigated. The sandwich plate contains Aluminium face sheets and a core which is made up of functionally graded (FG) porous graphene nanoplatelets (GNP) reinforced material. The pores are created throughout the core along the thickness direction by employing certain functions. The homogenized properties such as elastic modulus and density are obtained using Halpin-Tsai model and rule of mixture, respectively. The governing equations based on higher-order shear de-formation theory (HSDT) are developed using variational principle. The finite element method along with Newmark's integration technique is employed to investigate the impulse response of the sandwich plates. The influence of damping, porosity, GNP weight fraction, etc. is discussed. [ABSTRACT FROM AUTHOR]

This paper uses a stochastic finite element approach based on perturbation theory to explore the impact of uncertain material properties on the buckling characteristics of functionally graded porous (FGP) beams reinforced with graphene platelets (GPL). The first-order perturbation technique (FOPT) has been employed to accurately quantify diverse sources of uncertainties. A stochastic finite element formulation, ensuring C0 continuity, has been developed to calculate the stochastic buckling behaviour of FG-GPLRC porous beams. Convergence and validation analyses have been performed to validate the formulation's precision, comparing results with those obtained through a conventional Monte Carlo simulation. The Halpin-Tsai micromechanics model and Voigt's mixture rule have assessed the effective material properties at a homogenised level. Ultimately, the study delves into how material uncertainties influence the buckling responses of FG-GPLRC porous beams, particularly focusing on low variability (randomness) in key material design parameters like porosity content, nanofiller quantity, Young's modulus of the metal matrix, and nanofiller properties. The findings underscore that uncertainties in material properties significantly influence the buckling behaviours exhibited by FG-GPLRC porous beams. [ABSTRACT FROM AUTHOR]

This study compares the hydrogen sorption/desorption properties of graphite flakes and graphene sheets through thermogravimetric analysis (TGA) below 200°C. The graphene sheets were successfully synthesized by microwave-assisted method. The physio-chemical properties were characterized using XRD, Raman and SEM techniques. Further, the hydrogen sorption experiments were performed at 150°C for 15 minutes under 10 bar H2 pressure. Using TGA analysis, hydrogen desorption performance was investigated systematically. The hydrogen storage capacity is achieved as 0.66 and 1.03 wt.% by graphite flakes and graphene sheets, respectively from room temperature (RT) to 200°C. Additionally, graphene sheets desorbed ~1.30 wt.% hydrogen at isothermal temperature of 200°C within 10 minutes. These studies could be helpful in the development of effective and safe hydrogen storage systems for upcoming energy applications. [ABSTRACT FROM AUTHOR]

Phosgene is a toxic gas that is used in industries that cause major health problems. To monitor this gas leakage the efficient method is the nanomaterial-based gas sensor. Armchair Graphene Nano Ribbon (AGNR) is one of the efficient materials for gas detection. So, we employed the Density Functional Theory (DFT) based calculations to study the structural stability of the AGNR and metal atoms (Pd, Pt, and Sn) doped AGNR, the adsorption behaviour of AGNR towards phosgene and electronic properties of AGNR and metal atoms doped AGNR before and after adsorption of phosgene gas. With the formation energy calculations, we identified that all the systems were thermodynamically stable. The Pd and Pt-doped AGNR has shown strong adsorption towards the phosgene gas with chemisorption. Also, there is a huge amount of charge transfers taking place. The band structure and Density of States (DOS) results support the adsorption studies. Our results give insight into making a good gas sensor for the detection of phosgene gas. [ABSTRACT FROM AUTHOR]

As electric cars become more prevalent, the need for battery recycling grows in importance due to the environmental impact of spent batteries. Graphite, a material found in these batteries, can be recycled and converted into graphene, which can be used for synthesizing perovskite solar cells. This article compiled studies regarding quantifying and characterizing the amount of graphene produced from spent batteries and graphene-based solar cells. It was studied that the process involves compacting flake graphite from the batteries inside dialysis tubing with a platinum wire acting as the current collector. The synthesized graphene was utilized in fabricating solar cells, where it was combined with a mixture of titanium dioxide in an isopropanol solution and applied as the n-type collector layer. This article reviews many essential graphene solar cells from spent batteries, including the working principle of the cell, the main physical and electrical properties of cells, and the significance of graphene in solar technology. It was revealed that the yield of graphene obtained from graphite ranges from 38% to 65%, with large lateral sizes exceeding 30 µm. The graphene derived from spent batteries was suitable for fabricating solar cells, achieving a power conversion efficiency of up to 15.6%. [ABSTRACT FROM AUTHOR]

In prosthodontics, orthodontics, and implants, dental devices are becoming more popular for their functions. Medical device-associated infections are prevalent in dentistry. Since 2010, graphene-based materials have gained popularity, and biological research suggests antibacterial potential. This review aims to present a foundational overview of graphene and graphene antimicrobial properties and dental-coating applications as a solution to reduce medical device-associated infections. The protocol of this study is being registered in the international prospective register of systematic reviews (PROSPERO, ID: CRD42023427839). Cross-sectional studies with advanced search in Google Scholar, Pubmed, and ProQuest between 2013 and 2023 were included. Based on an advanced search on cross-sectional studies, there were seven articles that matched the inclusion criteria. Graphene, graphene oxide (GO), reduced graphene oxide (rGO) was a type of graphene in the included studies. Graphene-based materials have a vast surface area, great strength, thermal-electrical characteristics, and several functionalization choices for medical device-associated infections. Graphene has the potential to be utilized as a surface-coating technology to increase the utilization of dental appliances and decrease infections. We predict that rising concerns about medical device-associated infections in dentistry, along with the appearance of graphene as the most up-to-date biomedical application, will contribute to the advancement of bio-dental materials and engineering sophistication in future. [ABSTRACT FROM AUTHOR]

This work aims to measure the drilling operation and surface roughness of sisal fibre without filler (epoxy) matrix nanocomposites reinforced with innovative bi-directional sisal fibre with graphene laminated by hand layup. Materials and Methods: In surface roughness, sisal fibre reinforces. By making plates, resin and hardener form a matrix and graphene fills it. Sisal fibre without filler (N=20) and graphene (N=20) are tested in the control group. Results and Discussions: Sisal without filler (0 percent) and sisal with graphene (4 percent) have good surface roughness. SPSS programme indicates significance (p<0.05) and ANOVA analysis indicates 0.001. Conclusion: Sisal with graphene (4%) exhibits more surface roughness than epoxy matrix sisal without filler, within the study's limits (0 percent). The surface roughness of epoxy composites with 4% graphene (filler) was 15% higher than simple epoxy composites. [ABSTRACT FROM AUTHOR]

Recalcitrant organics have the potential to be extremely poisonous, mutagenic, and carcinogenic even in trace amounts. Complex and challenging organic wastewatersare produced by a variety of businesses, including those that use colors, tannery products, pharmaceuticals, landfill leachates, etc. Electrochemical oxidation as a wastewater treatment technique is continuously evolving for the removal of colors from textile effluents. Electro-oxidation is generating a lot of interest because of its versatility, simplicity, energy efficiency and cost-effectiveness. This study highlights the treatment of synthetic Reactive Orange 16 (RO16) dye wastewater by indirect electrochemical oxidation using two supporting electrolytes, NaCl and Na2SO4. In this work, a novel particle electrode using GO (Graphene Oxide) and GAC (Granular Activated Carbon) on Titanium (Ti) substrate was developed by high-temperature thermal decomposition in the laboratory for electrooxidation of RO16. The performance of this newly created electrodeTi/GO-GAC-RuO2−Sb2O5−CeO2 was examined on the percentageCOD reduction and decolorization of 200 ppm of synthetic RO16 dye solution. The operating parameters considered vital for all electrooxidation studies were pH, current density, electrolyte concentration, and electrolysis duration. NaCl and Na2SO4were employed as electrolytes to enhance solution conductivity. Using Ti/GO-GAC-RuO2−Sb2O5−CeO2electrode, maximum colorand COD reduction wereachieved at 98% and 88%, respectively. Additional investigation was also conducted in terms of instantaneous current efficiency (ICE), Energy Consumption (EC), and evaluation of kinetic rate constants. [ABSTRACT FROM AUTHOR]

We reported our preliminary results in our study of electronic band gap engineering of Graphene Quantum Dot by calculate the electronic properties of the bulk properties by means graphene. The calculation was done by density functional theory as implemented in quantum espresso (QE). The results showed that the graphene is the gapless semiconductor with fermi energy 5.223 eV. When the size of the graphene decreases until <10 nm, its band gap is tunable by vary its size. The challenge in this study is how we tune the gap as function of size of graphene which need the large supercell. The effect of the supercell's size on band gap will be reported in another publication. [ABSTRACT FROM AUTHOR]

Friction between cutting tool and workpiece generates heat, which can shorten tool life and impair the quality of machined parts. Thus, the use of appropriate lubricants is required to mitigate these issues. In this research, the use of different weight concentration of graphene nanoparticles (0.1 %, 0.5 % and 1.0 %) to augment commercially available vegetable-based oil, LB3000 was investigated using tribological test. Their performances were evaluated in form of the coefficient of friction, wear scar diameter, kinematic viscosity and thermal conductivity. Higher concentration of graphene was found to be more effective in terms of lowering coefficients of friction, reducing wear scar diameter, and improving kinematic viscosity and thermal conductivity. This study clearly demonstrates that a suitable combination of graphene nanoparticles in oil can improve tribological behaviour as well as lubrication performance. [ABSTRACT FROM AUTHOR]

Nowadays, polymers have been widely used in semiconductor field. The most famous thermosetting polymers that was being used was epoxy due to its excellent properties. Often conductive fillers of carbon allotropes such as graphite, graphene, graphene oxide and carbon nanotubes were added into the epoxy main matrix to change the nature of epoxy into conductive polymer composites. In this study, different loadings of graphene nano platelets (GNP) incorporated into main matrix of epoxy via solution mixing method followed by ultrasonication, targeted to improve the mechanical, thermal and electrical properties of the epoxy/graphene composite. Phenolic resin was blended with epoxy, forming co-existing miscible blend was aimed to improve the mechanical and thermal stability of the blend system. It was shown that the epoxy/graphene composite has the best flexural and fracture toughness properties at 0.4 vol%. The percolation of graphene was reported at 1.0 vol% and thermogravimetry analysis (TGA) showed that incorporation of graphene did not affect the thermal stability of the epoxy/graphene composites. With the graphene loading fixed at 1.0 vol% prior to the percolation of the nanoplatelets, different amount of phenolic resins was blended with the epoxy main matrix with the phenolic resin acts as a crosslinker to improve the mechanical and thermal stability of the blend system. It was reported that the optimum results of mechanical properties and thermal stability were found in ratio of epoxy:phenolic at 100:20 phr. Addition of phenolic resin into the epoxy/graphene system did not seem to have any effect on the electrical conductivity properties due to high miscibility between both resins where selective localizations of graphene nano platelets were inhibited. [ABSTRACT FROM AUTHOR]

Numerous scientific studies cover the effects of defects in the multiple applications of single-layer graphene. High atomic lattice perfection graphene samples have exceptional electrical and mechanical capabilities, however structural defects that can develop during growth or processing impair the functionality of graphene-based devices. In other instances, however, defects might be advantageous since they allow for the customization of the local properties of graphene and the achievement of new applications. The electrical composition of graphene can be affected by molecular defects. The resonant characteristics of defective and pristine single layer graphene (SLG) are investigated by the authors using a molecular structural mechanics method. In this work, Stone-Wales defects and divacancy defects are considered for the investigated with comparison of pristine SLG. Moreover, cantilever and bridged boundary conditions applied at the end of the SLG. Atomistic finite element (FEM) method based on Molecular Structural Mechanics (MSM) utilised for the analysis of armchair, zigzag, and chiral single layer graphene. [ABSTRACT FROM AUTHOR]

Throughout the Newns – Anderson model, the chemisorption process for atom-like semiconductor spherical quantum dot on perfect pure graphene depending on the normal distance between them had been investigated under the various effective parameters/functions of the adsorption. The physical solutions for quantum dot occupation energy levels are magnetic for all distance values from far away the graphene sheet, but nonmagnetic near the graphene sheet. The numerical way used to solve major equations, also the equations of occupation number and energy level position are solved self-consistently. [ABSTRACT FROM AUTHOR]

This study investigates the effect of nanofiller loading of graphene nanoplatelets and multi-walled carbon nanotubes on the characterisation of glass reinforced epoxy composite. The GNP-glass and MWCNT-glass composites were prepared using the hand lay-up and vacuum bagging method. The nanofiller weight fraction at 0.5, 1.5, 3, and 5 wt. % was being analysed. FTIR spectra were used to evaluate the GNP and MWCNT nanofiller's contribution to different crystalline formations in the epoxy matrix. The result indicates a variation peak in GNP-glass and MWCNT-glass reinforced epoxy composites due to nanofiller incorporation. The stretching vibration peak in the transmittance percentage was related to the better bond formation of the nanofiller with the epoxy matrix. [ABSTRACT FROM AUTHOR]

Aluminum alloys are popularly used in the aerospace industry due to their lightweight and high strength-to-weight ratio. However, cutting these alloys can result in various machinability issues such as tool wear, built-up edges, and material adherence on the cutting tool. To address these issues and minimize the use of lubricants, researchers are exploring alternative greener techniques. One such technique is the use of nano lubrication technology. In this research, the consequence of three cutting techniques - dry cutting, minimum quantity lubrication (MQL), and MQL dispersed with graphene nanoparticles - was experimentally studied to assess their impact on hole quality, surface roughness, and the number of holes drilled. The findings showed that the addition of graphene nanoparticles improved roughness quality, reduced tool wear, and increased the number of holes drilled, but had less impact on hole accuracy. This study highlights the importance of nanoparticles in enhancing the machinability of aluminum alloys and offers promising avenues for future research in this area. [ABSTRACT FROM AUTHOR]

The accumulation of carbon-based greenhouse gas effects, one of which is carbon dioxide gas (CO2)/methane (CH4), has been identified as the primary cause of global warming. Therefore, investigations into the separation of CO2 and CH4 received significant attention in order to achieve gas separation in industrial facilities. The graphene separation technique also received special attention because of its mechanical properties, which include the uniform dispersion of functional graphene and strong interfacial bonds between the modified graphene. Functional graphene has high thermal stability, and graphene is physically a novel material consisting of carbon atoms in a flat lattice configuration with its thinness and strength. However, the material of graphene is controlled by the chemical composition of its basic graphene oxide. Because of its hydrophilic characteristics and numerous oxygen groups on its surface, GO has been investigated for effective gas separation. This review research examined four designs based on GO-based materials: (1) 3D Hollow GO, (2) Thermally Reduced GO, (3) Multiply Oxidized GO, and (4) 3D Mesoporous GO. When deployed on an industrial scale, each design has unique constraints such as low stability, limited performance improvement, and design optimization. To help overcome these obstacles, this review paper performed a technological mapping of GO-based research based on existing issues. In addition, the highlights of advancements in preparation and assessment procedures, as well as approaches to improving the stability of GO and graphene's future prospects as an alternate gas separation material, are also discussed in detail. [ABSTRACT FROM AUTHOR]

Improper disposal of pharmaceutical waste in water is hazardous to the environment. Several ways have been developed to address this issue, with the photocatalyst being a well-known example. In recent years, there has been a surge in interest in the use of stable photocatalysts for water treatment. Here, we used a straightforward approach to fabricate nanocomposite films of chitosan/graphene oxide/TiO2 (Ch/GO/TiO2) via solution casting. The graphene oxide was synthesized via Hummer's method and characterized using UV-vis spectrophotometer, X-ray diffraction (XRD), Scanning electron microscope (SEM), and energy dispersive X-ray (EDX). The successful result of obtained GO was applied by combining with TiO2 in chitosan matrix to form (Ch/GO/TiO2) nanocomposite films. Films were made by varying the ratio of graphene oxide (GO) and titanium dioxide (TiO2) in chitosan matrix. The films were also characterized using FTIR, SEM and EDX. The photocatalytic degradation of acetaminophen (N-(4-hydroxyphenyl) acetamide) was investigated in a batch reactor which yielded a maximum of 10% of 50 ppm acetaminophen under UV irradiation for 120 minutes. [ABSTRACT FROM AUTHOR]

A 'discretized' version of the 2-dimensional (2D) 'Generalized Skettrup Model' (GSM) implemented at simulations on temperature-dependent harmonic and anharmonic fractions of the lattice thermal capacity of square graphene nano-flakes as well as of their size-dependent melting temperatures. All mentioned above thermal characteristics of those square graphene nano-flakes are evaluated merely based on features of confined interacting in-plane acoustic phonons with the static plane-wave basis, while contributions from their in-plain 2D optical braches and 'outplane' ('flexural') modes are ignored completely because of their insignificant impact on the fraction of the anharmonic lattice thermal capacity in vicinity of melting point of those nano-flakes(s). Effective interactions among the in-plane acoustic phonons are taken into consideration via 'tailored' temperature-dependent model parameter(s) of the 'discretized' 2D GSM. Obtained simulation results for the size-dependent melting temperature(s) of square graphene nano-flakes with the rib length ranging from ∼5 nm to ∼20 nm are discussed in comparison with their counterparts obtained via 'state-of-art' molecular dynamic simulations, nucleation theory, and atomistic approaches. [ABSTRACT FROM AUTHOR]

Graphene quantum dots (GQDs) attract huge scientific attention ever since they were discovered. They are the only 0-dimensional, water-dispersible graphene-based nanomaterial. They show (i) excellent biocompatibility; (ii) stable and tunable photoluminescence in the visible part of the spectrum resistive to photobleaching; (iii) large surface area; (iv) good solubility in water and polar organic solvents. Their astonishing properties stem from the structure: graphene in the core and a vast number of different oxygen-containing functional groups such as carboxyl, carbonyl, epoxy, hydroxyl, and lactone. Their lateral size is below 100 nm, and the height is from 0.5 to a few nm. Thanks to different oxygen groups, they have very reach chemistry; they can be easily processed, modified, and functionalized. GQDs can be modified after their synthesis using different chemical reactions, which lead to changes in oxygen content, the addition of heteroatoms, binding of target molecules. Heteroatoms can be built-in GQDs structure during the process of synthesis and usually, N, S, and P are selected. They can be produced in many different ways and starting materials and all of them are dived into two main groups: bottom-up and top-down methods. Due to a large number of diverse functional groups and high surface area, GQDs create complexes with ions, cations, biomolecules, organic molecules, etc. Thanks to this feature, GQDs are studied for the application in sensing heavy metal ions, selected anions, proteins, metabolites, hormones, enzymes, pesticides, organic colors, etc. Another exciting feature of GQDs is their ability to produce reactive oxygen species under visible light. [ABSTRACT FROM AUTHOR]

Recently developed cyanate ester based shape memory polymers (SMPs) have shown their potential in the use of space applications due to their exceptional durability in lower earth orbit environment. This research work focuses on changing the fibre lay-up configuration of the SMPC (based on cyanate ester) to study the variation of shape memory and mechanical properties. In this study, authors used a newly developed, cyanate ester based SMP with 0.6% (w/w) graphene nanoplatelets and 6 glass fibre layers for the fabrication of SMPC sheets. Shape memory properties and mechanical properties were measured for different fibre orientations such as (0/90°)6s layers (T), (±45°)6s layers (X) and sandwich layup of (0/90°)3s(±45°)3s layers (TX). According to the results (±45°)6s SMPC has shown the best shape fixity with less fibre damage in its shape memory cycles and (0/90°)3s(±45°)3s specimens have shown 100% shape fixity and recovery properties with minor damages. It can be concluded that the (0/90°)3s(±45°)3s type fibre lay-up configuration can be used for the SMPC components where both shape memory and mechanical properties are important. As a spacepotential material, developed cyanate ester based SMPC with X configuration could be used in Earth's orbital applications where gravity is minimum. SMPC with TX configurations can be most suitable for load-bearing applications as well as for complex shape programming applications. [ABSTRACT FROM AUTHOR]

MOSFET has been the most widely utilized electronic appliance in integrated circuits (ICs) since the beginning of the silicon-based semiconductor material (1970s). With the rapid development of the semiconductor industry, the feature size of MOSFETs has been drastically reduced. In this paper, the modeling 14 nm NMOS and PMOS horizontal double gate with deposit bilayer graphene, high-κ dielectric, and the metal gate is presented by using the Athena module while the characterization of the device is presented by using the Atlas module. It demonstrates that the virtual fabrication using Athena was successfully designed by using HfO2 and WSix as high-κ dielectric and metal gates, respectively, for NMOS transistors, and HfO2 and TiSix for PMOS transistors. The simulation shows that the VTH value of the 14 nm channel length is within 12.7% of 0.191 V and the IOFF value is lower than 100 nA/µm. The values of the VTH NMOS and PMOS were 0.20473 and 0.19154, respectively. In the meantime, the IOFF values for PMOS and NMOS devices were 45.0861 nA/µm and 4.59273 nA/µm, respectively. It proves that the value of the VTH and IOFF is in line with ITRS 2013 for high-performance applications. These findings are expected to serve as a benchmark for future efforts to fabricate 14 nm devices using bilayer graphene/high-κ dielectric/metal gate MOSFETs with gate lengths of 14 nm. [ABSTRACT FROM AUTHOR]

Carbon nano allotropes such as carbon nanotubes (CNTs) and Graphene are in high demand due to their high young's modulus, tensile strength, and low weight. These materials are also used as a coating in biomedical implants of Titanium (Ti-6Al-4V) and steel (316L Stainless Steel) alloy. Because of their lightweight, they are also used in electrochemical, optical, and biosensors. This study is focused on the stress analysis of pure CNT and Graphene beam structure. Numerical simulation is carried out using the theory of finite element analysis (FEA) in order to analyze the stress distribution in the beam under transverse load. Additionally, modal analysis is carried out on the beam structures to determine the natural frequency of vibration. The modal analysis is carried out for the first eight modes of vibration. Numerical study concluded that, the CNT beam experiences maximum stress of 223.4 kPa which is comparatively higher than the Graphene beam under similar loading and boundary conditions. However, CNT beam requires higher excitation force as compared to the Graphene beam to achieve the resonance condition. The results of this study can be used to optimize the CNT and Graphene based structure in the design phase by reducing the number of experiments or prototypes. [ABSTRACT FROM AUTHOR]

An essential part of the development of spintronic devices is the generation of spin current through charge-spin interconversion. It has been shown that proximity of a transition-metal dichalcogenide to graphene can significantly affect its magnetism and spin texture. Specifically, the spin-orbit coupling induced by the TMDC complements graphene's high-quality charge and spin transport. Among the most promising materials for charge-to-spin conversion research is 1T-TaS2, which includes both strong spin-orbit coupling and spontaneous formation of charge density wave (CDW) phase at low temperatures. Placing graphene on top of 1T-TaS2 results in the proximity induced spin-orbit coupling that depends on CDW phase. Here, using an effective tight-binding model combined with quantum transport calculations, we investigate the production of spin-polarized currents by the flow of an unpolarized current across a single layer of graphene proximitized with 1T-TaS2. We demonstrated an overall spin accumulation for the perpendicular spin component to the plane. Notably, the sign of the accumulated spin density depends on the nature of the injected current, either electron or hole. Furthermore, injecting electrons with spins in the longitudinal direction results in a spin separation perpendicular to the current direction, which indicates the occurrence of the spin Hall effect. Interestingly, these results remain consistent, regardless of the normal or CDW phases. Our findings provide new insights into the fundamental behavior of spin currents in graphene-TaS2 heterostructures, underscoring the potential of these materials for advancing spintronic devices. [ABSTRACT FROM AUTHOR]

Understanding some collective phenomena in two dimensional van der Waal structure has been recently on-trend. Particularly, in doped graphene, physics related to highly correlated electronic structures is extensively studied to explain the quantum behaviors like superconductivity (SC), charge density wave (CDW), etc. In this work, we investigate a latent feature of functionalized graphene, i.e., electron-phonon coupling (EPC), which is essential to achieve these symmetry-breaking states. This study demonstrates the role of oxygen functional groups (OFGs), incorporated in graphene lattice along out-of-plane direction, in increasing electron-phonon interaction. Two significant spectroscopic tools, X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy, are employed to measure this interaction. [ABSTRACT FROM AUTHOR]

Theoretical investigation onthe effect of carrier imbalance on conductivity of Double Layer Graphene System (DLGS) in presence of long range and short range scatterershas been done at T = 0 K within the framework of Boltzmann Transport equation. Wedescribed here with some variableparameters like carrier imbalancenr, ratio of dielectric constant εr, and distance dbetween two monolayers. The influence of the scattering mechanisms specifically Short range scattering and Coulomb chargeimpurity scattering have been assessed. It is found thatthe short range scatterers play vital role to affect the conductivity. Maximum conductivity has been attained in the absence of point defect. Influence of the screening effect between two monolayeris observed as interlayer distance d~20 nm. Further, italso noticed that as the value of relative carrier concentration nr increases, the peak is shifting towards higher value of εr. [ABSTRACT FROM AUTHOR]

We have reported theoretical study the effect of different dielectric environment on surface roughness induced scattering rate for double layer graphene structure DLGS. Our results suggest that the effect of dielectric environment on SRP is remarkable. We have shown that to have unperturbed conductivity with respect to changing interlayer distance between two graphene layers in DLGS, one should choose middle layer such that its dielectric constant is the same or very close to that of substrate material. [ABSTRACT FROM AUTHOR]

Background/Objectives: Graphene is a revolutionary discovery. It is credited as the lightest and strongest material available in the world. Its high-power density and energy density it is being considered a potential candidates as electrodes in supercapacitors, which in themselves are new to the market. The main objective of this paper is to highlight the usage and benefits of graphene in supercapacitors. Methods/Statistical analysis: Super-capacitors are barely a new technology. Due to its unique property of handling high power and high rate of charging or discharging, it is seeming as a solution for many problems. It is observed that using graphene in supercapacitors makes it more efficient and reliable. Therefore, here an attempt is made to review the effects and advantages of graphene-based supercapacitors. Findings: The graphene-based supercapacitors are highly efficient and able to handle more power and energy density as compared with the conventional ones. The numerous beneficial properties of graphene such as high conductivity, lightweight, high-power density, high energy density, high surface area, etc. make it the most suitable candidate for the electrode used for supercapacitors and have opened the gates for more graphene and other carbon nanostructure-based supercapacitors. Improvements/Applications: Supercapacitors prove themselves as an important element in the field of the flexible electronics industry. It is observed that the usage of graphene-based electrodes improves the performance of super-capacitors. Therefore, applications which involve flexible and stretchable consumer electronics graphene-based supercapacitors are highly desirable. [ABSTRACT FROM AUTHOR]

The article is devoted to the study of friction formed when using graphene-containing lubricants during cold and semi-hot drawing of semi-finished products and the formation of technical recommendations for their use. The results of an experimental study of various samples of lubricants at drawing operations of aluminum semi-finished products are presented. Recommendations are given on the choice of lubricant, considering the energy and power costs for operations and the quality of the resulting semi-finished products. [ABSTRACT FROM AUTHOR]

Two dimensional material like graphene, TMDC's have shown a lot of promises due to their excellent electrical and optical properties. Graphene devices fabricated so far relied on lithographic techniques which always leave an un-intentional residue on the graphene surface. Here, we have created a bilayer graphene device avoiding the conventional lithographic procedure by transferring the graphene layer directly on top of the metal electrodes. We tune the carrier density by the application of an electrolyte top gate, and a high doping level (∼ 1013/cm2) can be accessed due to the formation of a nanometer-thick Debye layer. We performed in-situ Raman spectroscopy by varying the carrier concentration. A prominent blue shift of the characteristic G peak was noticed with increasing carrier concentration, originating possibly due to enhanced electron-phonon interaction. Moreover, we observed a splitting of the G peak at higher doping concentration, may arise due to mixing of symmetric and antisymmetric modes by breaking the layer symmetry of the bilayer graphene. [ABSTRACT FROM AUTHOR]

Here, we report low frequency noise measurement in a top gated CVD graphene device using a lock in amplifier-based ac technique at room temperature. We tune the carrier density of graphene by electrolyte-gating through which a wide range of carrier density can be accessed due to formation of nanometer thick Debye layer at the gate interface, offering large capacitance. The power spectral density mostly follows 1/f type behavior. By varying the carrier density, the noise magnitude shows a dip near the charge neutrality point and increases with density. The behavior is unusual compared to the reported data on exfoliated graphene device and can be explained through the charge exchange between the interfacial traps and graphene. [ABSTRACT FROM AUTHOR]

This paper focuses on aero graphene and carbon nanotube (CNT) aerogel, both of which will find applications in aircraft, including the battery, the engine, the pitot probe, the wings, the fuselage, and the front glass of the plane. Because of the buoyant force, these materials will also protect the aircraft from rain and wind. There Aero graphene is made by decreasing a graphene oxide solution to produce a hydrogel. Freeze-drying replaces solvent in pores with air. 3-D printing can produce aero graphene. This is a scientific breakthrough. Graphene in gel makes resin. UV LED light may turn graphene resin into a solid in a furnace. Next-generation aircraft will have aero-graphene-coated hull, wings, and cockpit glasses. Aero-graphene gives planes a strong, light structure. [ABSTRACT FROM AUTHOR]

A closed-water activation loop is being built at the Jožef Stefan Institute TRIGA reactor in Slovenia to serve as a well-defined and stable source of high-energy gamma rays and neutrons. The radial piercing port, which penetrates the graphite reflector and touching the reactor core was chosen for the installation of the closed-water loop due to the high neutron flux and favourable shielding conditions of the surrounding concrete bioshield. The main objective of this work is to assess the neutron and gamma dose field outside the port to obtain important details for the final design of the inner part of the irradiation facility and to assess the background noise for the detectors. The main part of the work consists of the design of the shielding plugs and the construction of a detailed MCNP model of the whole irradiation facility. The dose field calculations were performed with a two-step hybrid transport approach using ADVANTG for variance reduction and MCNP for particle transport. Such deep penetration and shielding calculations are challenging and computationally intensive. The results showed that the dose rate using shielding plugs is more than 7 orders of magnitude lower compared to an empty open port. To reduce the computational uncertainty, further optimisation of the ADVANTG input is essential. The final design of the shielding plugs is described. Additional lead shielding blocks will be added outside the port afterwards if needed. [ABSTRACT FROM AUTHOR]

The petro fuelled engines is a major source of contribution in the automobile sector serving the economy to a better extent. On the other hand, alarmingly the exhaust from the engine peaks up day-by-day resulting in environmental and atmospheric pollution shooting up HC, NOx, CO emissions. It therefore necessitates the need to focus on reduction of engine emissions without compromising the performance. Such results could be achieved by modifications in the fuel. The combined effect of Exhaust gas Recirculation and alternate fuel contributes to less emissions where in there is a reduction in the performance. This shortcoming can be overcome by adding nanoparticle in the existing diesel and biodiesel. Nanoparticles enhances the properties of blended fuel. In the present investigation, Calophyllum Inophyllum Methyl Easter biodiesel was extracted by transesterification process and its blends were prepared in the proportion of 20% and 100%. The Graphene Nano particle was dispersed into a pure diesel and biodiesel with an amount of 25ppm, 50ppm, 75ppm and 100ppm by ultrasonic method. The property tests were conducted according to ASTM standards to determine flash point, fire point, viscosity, density, calorific value, Acid number and cetane number. The results unveils that there is a good considerable improvement in the fuel properties which can be set as a bench mark for further experimentation. [ABSTRACT FROM AUTHOR]

Silicon is the most widely used semiconductor material that meets the current needs of the electronic industry. To go in coordination with Moore's law, devices are miniaturized and are expected to give better performance. But silicon devices has its own limitations when they are scaled down in terms of dimensions that leads to degradation of device performance. Due to this industry has reached closed to the point of end of silicon era. Researchers in the field of academics and industry are indulged in finding the alternatives of silicon based field effect transistors. Graphene, a 2D nanomaterial is being studied widely to be employed as channel material. Its potentials are proved with its extraordinary physical, dimensional, thermal and optical properties. In recent times, many studies have been done on the graphene field effect transistror and much advancement have been achieved in this field. This research work is based on the study of graphene field effect transistors (GFET). As optimization is the need of every new research, this work is an effort to achieve graphene field effect transistor optimization. Changing the dimensional and other material properties of the device the variations in the I-V characteristics are observed. Finally, a device with optimized parameters is suggested that gives better performance characteristics. These parameters can help for the graphene FET designers while fabrication. [ABSTRACT FROM AUTHOR]

Doping with graphene nanosheets has attracted significant interest from researchers to enhance the structure and properties of nanomaterials because of graphene's unique properties and broad and essential applications. The study aims to focus on the effect of functional groups of both polymers and nanomaterials to fabricate a new nanocomposite consisting of poly (acrylamide) (PAAm) with poly (vinyl alcohol) (PVA) before and after the addition of graphene oxide nanosheets (GO) and studying its structural and optical properties. The developed method (dissolving with water, mixing, sonication, and casting) showed success in fabricating new nanocomposites for the first time by mixing these components with a ratio of 4.5: 4.5: 1 as percentages (PAAm: PVA: GO). Samples showed homogeneity of the polymer mixtures with each other and the excellent dispersion of graphene oxide nanosheets in the new polymer nanocomposite as exhibited by optical microscopy. The spectra of the Fourier infrared spectroscopy showed the strong interfacial interaction of the two polymers in the polymeric mixture with GO nanoparticles as nanocomposites. Also, X-ray diffraction showed shifting in some peak positions and increased crystallization of the polymers in the nanocomposites. The nanocomposites showed a notable improvement in the optical properties due to doping the polymeric mixture with graphene oxide compared with their blended polymers. The energy gap also significantly decreased after the contribution of graphene oxide up to 136% and 900% for the permitted and prohibited direct transfers, respectively. These results exposed promising nanocomposites for widespread applications such as solar cells. [ABSTRACT FROM AUTHOR]

In this study, thin films were prepared from pure TiO2 nanoparticle doped with graphene (3, 5, 7%)wt on glass bases using pulsed laser deposition (PLD) technique, the thickness of the prepared films was about 200 nm. The(AFM) analysis results showed that the titania layer surface is well covered with particles that are uniformly distributed over the surface, pure TiO2 thin film showed a slightly low roughness, The average surface roughness increase and the average particle size ranged between (50-80) nm, this may be due to the big clusters formed by the coalescence of two or more particles. EDX analysis also shows that the results of the ratios were close to the required ratios. The results showed in the scanning electron microscope that the increase in the percentage of doping leads to the crystallization and agglomeration of graphene oxide and its rise over the Titanium dioxide (TiO2) until the surface reaches the state of collapse. The Electrical properties results showed that electrical conductivity increases with an increase in the doping ratios due to an increase in crystallization in the films as a result of the increase in size Granular, which leads to a decrease in the density of the grain boundaries and also an increase in the concentration of carriers, which leads to an increase in the electric current, which causes an increase in electrical conductivity. [ABSTRACT FROM AUTHOR]

Graphene based microstrip patch antenna and CNT based microstrip patch antenna using FR4 dielectric substrate were designed at frequency range (5GHz to 6.5GHz) in order to optimize gain and return loss. Return loss and gain of Graphene based microstrip patch antenna using FR4 dielectric substrate (N=16) were compared with CNT based microstrip patch antenna using FR4 dielectric substrate (N=16) using Ansoft HFSS simulation tool. Graphene based microstrip patch antenna using FR4 dielectric substrate has significantly higher gain(2.20 dB) and less return loss (-12.823 dB) (p<0.05) than CNT based microstrip patch antenna using FR4 dielectric substrate with less gain(1.57 dB) and high return loss(-11.80 dB). Optimal frequency for maximum gain and less return loss of Graphene based microstrip patch antenna and CNT based microstrip patch using FR4 dielectric substrate was 5.0 GHz and 5.4 GHz respectively. Within this limits of study graphene based microstrip patch antenna using FR4 dielectric substrate of frequency 5 GHz offer high gain and less return loss. [ABSTRACT FROM AUTHOR]

The primary goal of this work is to increase and compare the impact strength of Sisal fiber-reinforced epoxy composites with and without graphene filler. Sisal fibre is employed as a reinforcement material using graphene as a filler. This investigation requires sisal fibre 220GSM, resin (LY559), and hardener (HY951). The laminate was made using the hand lay-up technique. Twenty samples (N=20) were collected in an experimental and control group. The Charpy impact test was performed on sisal fibre without filler, sisal fibre with graphene 2% and 4% filled composites. The Charpy impact testing equipment was used for testing, according to the V-shaped notch. The sisal fibre epoxy composite had an impact strength of 2.8 J. The impact strength of a sisal fibre epoxy composite containing 2% graphene filler and 4% filler was 2.9 J and 3.8 J, respectively. The statistical significance of sisal fibre graphene filler reinforced epoxy composite was determined using SPSS-V26 software and was 0.0001 (p<0.05). Within the scope of this work, graphene composites containing 4% sisal fibre demonstrated much greater impact strength than sisal fibre epoxy composites. [ABSTRACT FROM AUTHOR]

The latest contemporary part of the graphene group, graphene quantum dots (GQDs), have piqued the response of researchers in latest years due to its remarkable characteristics and medicinal applications. Graphene quantum dots (GQDs) were hypothesized to provide novel or enhance existing technologies for bioimaging, medication delivery, and diagnostic detectors for disease detection. Graphene quantum dots have lately been established in a number of areas, including medicine, as antimicrobial agents, owing to their superior biocompatibility over conventional inorganic quantum dots, however the structural characteristics that lead to GQDs' biological activities remain unknown. In this review, we have covered the various areas of Green synthesized Graphene Quantum Dots (GQD) from Phyllanthus Emblica. The constituents of Phyllanthus Emblica, along with their chemical composition are described in the phytochemistry. The green approaches such as solvothermal and hydrothermal methods were discussed for the synthesis of nanoparticles. Further characterization of Graphene Quantum dots such as XRD, FTIR analysis, UV spectroscopy and imaging techniques SEM and TEM are addressed. Finally, the latest advancements in the field of Graphene Quantum Dots (GQD) from Phyllanthus Emblicawere briefly reviewed. [ABSTRACT FROM AUTHOR]

Graphene quantum dots (GQDs) are normally considered zero-dimensional and carbon-based materials. They have got outstanding attention because of their unique properties and various prospective applications such as optoelectronics, biological, and energy. Synthesis of GQDs was done using bottom up and top-down methods such as including solvothermal hydrothermal / technique, oxidative cleavage, ultrasonic microwave-assisted method, electrochemical oxidation, controllable production, and carbonization. The structural morphology and chemical constituents of Graphene quantum dots are characterized by SEM, HR-TEM, VIS-Spectroscopy, FTIR, XRD−Spectroscopy, and electrochemical techniques. Furthermore, Graphene quantum dots are capable of fabricating nanocomposites in combination with certain materials and demonstrate higher performance. Here, we mainly focus on the synthesis of GQDs using biological sources (Areca catchu), which has a lot of advantages as it uses cheap, non-toxic, easy operational techniques, fast, relies on renewable resources, and direct post-handling stages. The Graphene quantum dots synthesized from the green source are vital in different fields of application. From this review the existing techniques for the fabrication of graphene quantum dots are also explained. [ABSTRACT FROM AUTHOR]

Super capacitors or Ultra capacitors have slowly become the next generation energy storage devices for the rapidly evolving EV industry. Graphene shows promising application in supercapacitors by having excellent properties like electrical conductivity, high chemical stability. This paper mainly reveals the study on graphene EDLC super capacitor which has a drawback of rapid discharge, in-order to overcome this effect graphene is synthesised and fabricated such that discharge rate is minimized. This study is also accompanied with activated carbon based EDLC super capacitor and its testing. Overall the performance and characteristics of graphene super capacitor was impressive and yielded best results compared to activated carbon supercapacitor. [ABSTRACT FROM AUTHOR]

Graphene is produced using green synthesis approaches from rice husk, called rice husk-derived graphene (GRHA). Due to the high silicon content compared to carbon in raw rice husks, this research will add sodium hydroxide (NaOH) treatment to reduce silica in the resulting GRHA, commonly known as desilication. Rice husk ash (RHA) was mixed with NaOH solution by stirring at 80 °C for 3 hours, followed by filtering, washing, and drying. Variation in NaOH concentration is 0.5, 1.0, and 1.5 M to study the optimal one added between the carbonization and activation at high temperature with potassium hydroxide (KOH). EDS spectra confirmed that the NaOH treatment could reduce silica, and the most optimal concentration was found at GRHA-1.0, as it possessed the highest carbon content of up to 80.27%. SEM images also showed a crumpled structure of layered graphene with a thickness of several nanometers. XRD patterns showed that the three samples still contain silica with a high degree of crystallinity. It is due to the thermal treatment, which is also responsible for converting silica from amorphous to crystalline. This methodology is a promising way to increase the added value of rice husks with a cost-effective process while reducing the wasted as an environmental burden. [ABSTRACT FROM AUTHOR]