Graphite Powder Research Articles

Bioinspired High-Strength Borate Cross-Linked Microfibrillated Cellulose Composite Laminate with Self-Extinguishing Flame Retardance and Superhydrophobicity for Self-Cleaning.

The cross-linking of borates enhances the intercellular structural connection, resulting in the creation of a mechanically superior structural material composed of lignocellulose and borate. This is accomplished by employing a mechanical pretreatment procedure and a binder-free hot-pressing method. Nevertheless, these materials frequently encounter constraints in humid environments, making it challenging to simultaneously achieve the desired performance objectives. Here, the prepressed bulk of microfibrillated cellulose is modified and subjected to hot pressing, while ensuring that the enhanced physical and mechanical properties of lignocellulosic recombinant materials are maintained. This modified material is termed the microfibrillated cellulose composite laminate (MCCL). These findings indicate that the application of compression, shear, and friction forces during hot-pressing results in the formation of a compact laminated structure using pine lignocellulose. The self-cleaning MCCL exhibits significantly improved mechanical properties compared with untreated lignocellulose materials (ULM). Specifically, the flexural strength (MOR), modulus of elasticity (MOE), and internal bonding strength (IB) of self-cleaning MCCL are found to be 5 times, 2.5 times, and 4.1 times higher, respectively, than those of ULM. This improvement in the pine lignocellulose can be attributed to the enhanced layering and branching that occurs during mechanical milling. This results in a higher proportion of ester and hydrogen bonds, as well as an increased exposure of hydroxyl groups. As a result, the modified MCCL exhibits self-cleaning properties, as evidenced by its surface water contact angle (WCA) of 152°. The rolling/jumping water droplets, which contain pollutants, effectively remove graphite powder from the surface, leaving it clean. Moreover, MCCL demonstrates exceptional dimensional stability and flame-retardant self-extinguishing properties, making it highly promising as a structural material in engineering technology.

Sustainable approach of La doped CuFe2O4 nanomaterial for electrochemical lead and paracetamol sensing action with multiple applications

This present research aimed to investigate the novel applications of synthesized La doped CuFe2O4 nanomaterial (LCF NMs) using renewable bio-fuel (Aegle Marmelos extract) by combustion process. The sensor applications were accomplished by modified electrode using LCF NMs with graphite powder and examined its excellent sensing action towards heavy metal (Lead content) and drug chemical (Paracetamol) substances. The thermodynamics of redox potential and super-capacitor behavior of LCF NMs were investigated through Cyclic Voltametric (CV) and Electrochemical Impedance Spectral (EIS) methods under specific conditions at scan rate of 1 to 5 mV/s. The heterogeneous photo-catalytic process of prepared NMs on Fast orange Red (FOR) dye-decolouration was investigated and noted its excellent degradation (91.7%) at 90 min using 20 ppm of dye solution and 40 mg of synthesized samples under Sun-light irradiation. Further, the antibacterial activity of synthesized NMs is investigated against various strains of gram positive (Bacillus subtillis) and gram negative bacteria (Pseudomonas aeruginosa), which confirms that the LCF NMs have higher activity towards gram positive bacteria with an average inhibition zone of 19 mm. This synthesized LCF NMs is a multi-functional material with stable and eco-friendly materials.

Battery Thermal Management System on Trapezoidal Battery Pack With Liquid Cooling System Utilizing Phase Change Material

Abstract Electric vehicles (EVs) have grown in popularity in recent years due to their environmental friendliness and the potential scarcity of fossil fuels. Lithium-ion batteries (LIBs) are commonly utilized in EVs and hybrid electric vehicles (HEVs). They have a high specific charge, a high density of power, and a long life. A revolutionary design of a trapezoidal battery pack with a liquid cooling system based on composite phase change material (CPCM) is proposed in this research. The phase change material (PCM) is paraffin wax (PA), and the high thermal conductivity particles are graphite powder (GSP). CPCM is made in three different compositions and is filled in between cells with a 5 mm gap. Because PCM has a low thermal conductivity, it is filled with GSP, a high thermal conductive particle. The thermal conductivity is increased from 0.25 to 2.7 W/m K, which increases the heat transfer rate significantly. By adjusting different coolant flow velocities at varied discharge rates, the performance of the battery pack is examined. During the experiment, the discharge rates of 1 C, 2 C, and 3 C were used at a 28–30 °C ambient temperature. According to the findings, a trapezoidal battery pack based on CPCM exhibits a more efficient rate of heat transfer than a battery pack based on PCM. Moreover, BTMS with a liquid cooling system achieves consistent temperature distribution, with the maximum temperature remaining within the ideal range of below 45 °C under all test conditions.

Two-dimensional layered rGO-MoS2 heterostructures decorated with Fe3O4 nanoparticles as an electrochemical sensor for detection of para-nitrophenol

In this study, reduced graphene oxide–molybdenum disulfide/iron oxide (rGO-MoS2/Fe3O4) nanocomposite, in which rGO nanosheets act as a substrate for Fe3O4 nanoparticles and the MoS2 nanostructure, was synthesized. The rGO-MoS2/Fe3O4 nanocomposite was synthesized with use of molybdenum disulfide, iron(III) chloride hexahydrate, and graphite oxide powder by application of the microwave method. The hexagonal structure of rGO-MoS2 along with the cubic geometry of Fe3O4 was confirmed by X-ray diffraction, while the decoration of the layered structure of rGO-MoS2 with Fe3O4 nanoparticles was visualized in scanning electron microscopy images of the nanocomposite. Increase in the intensity of the D band of the nanocomposite, when compared with rGO, in Raman spectra further indicated that the presence of Fe3O4 and MoS2 induced non-graphitic defects in the nanocomposite. The as-prepared sensor was applied for the electrochemical sensing of p-nitrophenol. Cyclic voltammetry was used to study the behavior of p-nitrophenol, while differential pulse voltammetry was used for a concentration study. Real samples of water, viz., distilled water, tap water, and river water, were used for this study. The detection limit obtained was 0.8 μM, and good sensitivity of 0.71 μA μM−1 cm−2 was achieved. This study provides motivation for the use of nanocomposites of carbon and transition metal dichalcogenides over use of metal-based nanoparticles.

Fe–Pd nanoflakes decorated on leached graphite disks for both methanol and formic acid electrooxidation with excellent electrocatalytic performance

This paper introduces a unique and simple method for fabricating of inexpensive electrocatalysts for use in direct methanol fuel cells. The leached Fe1–Pd1 NFs/graphite (leached Fe1–Pd1/graphite) disk electrode was successfully obtained via uniform dispersion of Zn powder into the matrix of commercial graphite powder (98%), pressing under optimized pressure followed by the treatment in H2SO4 solution containing Fe+2 and Pd+2 cations, leading to the partial leaching out of Zn from graphite matrix, as well as partial electroless substitution of Fe–Pd nanoflakes with Zn metal. Based on the morphology studies, binary Fe–Pd nanoflakes with a large surface area uniformly dispersed on the leached graphite disk. The leached Fe–Pd/G disk showed the exceptional electrocatalytic activity toward methanol and formic acid oxidation without electrocatalyst poisoning being observed, in contrast to the leached Pd/graphite and leached Fe/graphite disks. This is due to the high surface area, and synergistic effect of Pd and Fe. The findings of this work may be used for the mass manufacture of graphite-based disks for commercial fuel cell applications using available graphite powders. The linear range of washed Fe1–Pd1/G electrocatalyst for measuring methanol was about 0.1–1.3 M, and its detection limit was calculated at about 0.03 M. Furthermore, the linear range of the nanocatalyst for measuring formic acid was about 0.02–0.1 M, and its detection limit was calculated at about 0.006 M.

Ultrasensitive assay of atrazine in food and water samples

AbstractAtrazine is the pesticide that is found in surface water sources more frequently than any other pesticide. Therefore, the paper describes ultrasensitive detection of atrazine from fruit and water samples, using on‐site screening platforms incorporating stochastic microsensors based on graphite powder modified with 4‐tert‐butylcalix [4] arene and with calix [4] arene‐25,26,27,28‐tetrol. Limits of determination of 0.1 fmol L−1 were recorded while the sensors could have been used on wide concentration ranges, between 0.1 fmol L−1 and 0.1 mmol L−1. Recoveries higher than 95.00 % were recorded when used for the assay of atrazine in water, fruits and vegetables.

A novel particle electrode fabricated by graphite-assisted alum sludge for effective diuron degradation in wide pH ranges

The removal of diuron in electrochemical advanced oxidation process is typically limited by the solution pH. In this study, graphite powder (GP) was successfully doped in alum sludge (AS) by a sol–gel and embedding method and then calcined at 700 ℃ to prepare a novel particle electrode (GP/AS). The results showed that the GP/AS system can effectively degrade more than 82 % of diuron over a wide pH range (3–11) within 40 min. This was attributed to the surface-bonded free radicals and 1O2 generated in the GP/AS system resisting the influence of pH on diuron degradation. The generated graphite structure and electron hole accumulation of GP/AS, which greatly promoted the formation of active species, were systematically characterized using scanning electron microscopy, X-ray powder diffraction, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. In addition, five pathways of diuron degradation were proposed, with similar steps being the main targets attacked by reactive oxygen species, including the aromatic ring, amide group, and methyl group. The dominant step was methyl group hydroxylation. The findings of this study provide an efficient and sustainable method for the application of reused waste mineral materials in water remediation.

Compressive and Shear Strength of Kevlar based Nano Composites

The Fibre Reinforced Composite (FRC) material consists of building materials in macroscopic level by having fibres and resin as reinforcement and matrix material respectively. It has different physical and chemical properties that were bonded together in order to get new material with different required characteristics from individual components. The properties of the composites are largely depending on the matrix and reinforcement materials. The matrix strengthening process by introduction of fine nano particles in composite laminate was done in this work. In order to study the effect of nano particles, the composite consists of Kevlar- 49 (K49) fibre in woven form with epoxy resin as matrix was considered. All the test specimens have been prepared with 12 layers of K49 to build 3mm thickness using vacuum bag moulding method. The K49 fibre in form of plain-woven type were chosen as reinforcement material. The nano fillers such as Titanium dioxide (TiO2), Calcium Carbonate (CaCO3) and Graphite powder (Gr) were used as nanomaterial added in the matrix and was compared with pure K49 reinforced composites for better performance. The TiO2, CaCO3 and GR nano fillers were constituted on various weight ratios in FRC. The structural properties like compression and shear strengths were determined as per ASTM standards. The fracture behaviour for all the categories of laminate has been detailed and reported using scanning electron microscope.

Surface Hardening of CP Ti by Laser Hardening and Development of Ti/TiC Surface Composite by Laser Sintering Technique for Wear Resistant Surface

This study deals with the hardening of titanium surface by carburising of CP Ti Gr 2 substrate by using laser sintering process. The objective of this project is to harden the surface to improve surface wear resistance of titanium. In this study graphite powder is used as source of Carbon. Carbon from graphite reacts with titanium and TiC layer of 109 micron was measured on the titanium surface. The microstructure and phase analysis results show that presence of only TiC phase on the surface of the titanium substrate. TiC grains are nearly 5 times finer than titanium substrate grains. Grain refinement of TiC phase all over the surface of the substrate resulted in increase in hardness and development of significant wear resistance surface in titanium substrate. Hardness of TiC layer was found to be 2191Hv which is nearly ten times higher than the substrate titanium. Wear test results of pin and disc type shows negligible wear rate as compared to CP Ti substrate. TiC grains are nearly 5 times finer than titanium substrate grains.

Contribution to the non-destructive evaluation of bituminous mixes by electrical measurements

The incorporation of additives into bituminous mixes is a very important technique for improving the mechanical and electrical properties of the pavement body. The purpose of this work is to present and interpret the different results of the tests carried out in the laboratory; such as FENIX direct tensile test and electrical resistivity test. In this work, we will present comparative studies between the mechanical and electrical characteristics of bituminous mixes based on conductive additives (steel fibers and graphite powder). This comparison makes it possible to classify these resulting materials as materials that have the ability to respond to different multifunctional applications.

Plant Transpiration-Inspired Biomass-Based Device with Underwater Oleophobicity for Efficient General-Purpose Solar-Driven Oily Wastewater Purification.

The remediation of wastewater containing oily pollutants is imperative to mitigate the serious threats posed to the safety of fresh water, human well-being, and the environment. Current membrane separation technologies are severely restricted by their limitations for separating various types of oily pollutants with low sustainability. Herein, by imitating the plant transpiration in nature, we designed a solar-driven device composed of natural biomass sugar cane stem, chitosan/carboxymethyl cellulose, and graphite powders to separate versatile oily pollutants from the wastewater. Owing to its superior solar absorption capacity, microchannels for water transportation, and underwater oleophobicity, the resultant evaporator not only exhibited an excellent evaporation rate of 1.41 kg m-2 h-1 but also demonstrated an admirable purification efficiency of 99.9% for oily wastewater. Moreover, the device can maintain a stable evaporation rate and the original structure even in oily wastewater containing strong acid, alkali, or hypersaline components. Therefore, this work provides an effective approach to producing clean water from versatile wastewater.

Thermoelectric properties of metashale geopolymer mortar doped with graphite powder

Building materials with favorable thermoelectric properties can become a supplementary source of clean energy due to their ability to convert waste heat into electric energy. Depending on the thermoelectric conversion effectivity defined by the Seebeck coefficient, constructions made of these materials can serve as civil engineering energy harvesters. Since the conversion effectivity of common calcium(alumino)silicates (cementitious materials, geopolymers) is low, doping with electrically conductive admixtures is a crucial step to handle the issue. The paper is focused on the design of metashale mortar doped with graphite powder (3 wt.%), determination of its common material properties, as well as experimental determination of thermoelectric properties. The maximum thermoelectric voltage (161.65 mV, ΔT = 130 °C), Seebeck coefficient (538 μV K-1), and figure of merit (∼ 10-9) revealed significantly better thermoelectric performance than cement pastes or alkali-activated slags doped with multi-walled carbon nanotubes and if of promising thermoelectric conversion potential.

A novel approach for recycling agricultural wastes in the synthesis of nanomaterials and their composites

In this study, main focus has been drawn on the utilization of agricultural waste sources to synthesize nanomaterials. Graphene oxide and nanocellulose were prepared using rice husk ash and sugarcane bagasse, respectively. Further, their nanocomposites were also prepared in (1:1) ratio of graphene oxide and nanocellulose. The synthesized nanomaterials from agricultural waste were compared with those prepared from conventional sources through varied characterizations. Scanning electron microscopy, transmission electron microscopy, fourier transform infrared spectroscopy and N2 adsorption-desorption analysis was performed to examine the structural, functional and surface properties of the prepared nanomaterials from different precursors. High resolution imaging revealed better structural characteristics of the nanomaterials fabricated from agri-waste precursors. SEM images showed well exfoliated structure of GO and porous nature of NC. The folded layers of GO represent the presence of hydroxyl groups in the TEM images of GO @ graphite powder. TEM images of nanocellulose showed circular shaped nanoparticles of NC @ cellulose powder. Fourier transform infrared spectroscopy confirmed the presence of all the essential functional groups in the structure of prepared nanomaterials. The nanocomposites prepared using agricultural waste sources and conventional sources were inspected by N2 adsorption-desorption analysis, which demonstrated that the nanocomposites prepared from agri-waste sources exhibits much higher specific surface area than that of prepared from conventional precursors. R2 possess specific surface area of 82.832 m2 g−1 while, R1 possess only 6.721 m2 g−1. N2 adsorption-desorption analysis revealed the pore volume, pore diameter, micropore volume, micropore area and surface area of the prepared nanocomposites. The nanomaterials prepared using agricultural waste products shows desirable characteristics in all aspects which makes them equally applicable in energy storage devices, food packaging, drug delivery systems, nanosensors and water filtration systems.

Fast and novel multiwalled carbon nanotubes decorated with metal oxide nanoparticles for potentiometric detection of a prohibited medication in sports acebutolol hydrochloride

A straightforward approach for creating fast and novel potentiometric sensors that are modified with multi-walled nanotubes (MWCNTs) was described. The impact of the selective sensor's material was studied. The suggested sensors were successfully fabricated for instant and fast detection of the prohibited β-adrenoreceptor blocking agent acebutolol hydrochloride (AC) in commercial products. Acebutolol-phosphomolybdate (AC-PM) carbon paste sensor was formed by mixing AC and phosphomolybdic acid and graphite powder in the presence of o-nitrophenyl octyl ether (o-NPOE) as a plasticizing agent. The functionalized AC-PM-MWCNTs and AC-PM-MWCNTs-Al2O3 nanocomposite sensors were prepared and all parameters affecting the sensors' potential responses have been investigated as well as the green synthesis of Al2O3NPs has been characterized using various microscopic and spectroscopic techniques. AC-PM-MWCNTs and AC-PM-MWCNTs-Al2O3 nanocomposite sensors demonstrated linearity of 1.0 × 10−7-1.0 × 10−2 and 1.0 × 10−8-1.0 × 10−2 mol L−1, respectively with regression equations −53.571x + 423.24 (r = 0.999) and −57.107x + 518.54 (r = 0.999). It also revealed excellent selectivity and sensitivity for the determination and quantification of AC. The developed potentiometric system was suitable for the determination of AC in bulk powder and commercial products.

Graphite Separation in Sunflower Oil and a Possible Food Monitoring Sensor via Near-infrared Spectroscopy

Introduction: As a quick and non-destructive testing method, Fourier transform infrared (FTIR) spectroscopy has become more popular for identifying food adulteration, manipulation, and deception. Sunflower oil is a widely used food item that may be contaminated or even adulterated with potentially harmful chemical substances associated with health issues. Methods: In this regard, this study was carried out to examine the applicability of near- and midinfrared spectroscopy to identify modifications in the pure sunflower oil and sunflower oil dispersed with graphite. The dispersion of graphite powder in sunflower oil was achieved using the ultrasonic technique. The samples were analyzed using FTIR spectroscopy and transmission electron microscopy. Results: Changes in the FTIR signal were observed, indicating changes in the hydrogen atoms distribution within the solution. The flattened peak at 3470 cm-1 was associated with the overtone of glyceride ester carbonyl absorption compared to pure SO. Additionally, the stretching vibration of carbonyl groups of triglyceride esters occurred as a significant absorption band at 1754 cm-1, and the FTIR absorption at 1447 cm-1 was absent. Transmission electron microscopy (TEM) analysis showed transparent layers of graphene sandwiched with sunflower oil with a distinct flake-like shape Conclusion: These findings support dispersed graphite in sunflower oil to check the food quality.

Tribological study on cast iron based, graphite and CNT enriched hybrid HVOF coating from room temperature to 300°C

ABSTRACT In this article, eco-friendly graphite has been produced from the carbonised rice husk, an environmental waste. Graphite, carbon nanotube (CNT) and cast iron powder were blended to produce the hybrid coating material. This hybrid coating material was deposited over the cast iron substrate using HVOF thermal spray. The microhardness of the coated sample increased by 42% as compared to the substrate. The morphological and elemental analysis was carried out using SEM, XRD and raman spectroscopy. The residual stresses developed in the coated sample were measured using an X-ray analyzer and found to be compressive, indicating a stable coating. A tribological investigation was carried out on a Pin-on-disc tribometer at ambient, 150°C, and 300°C temperatures. The coefficient of friction and specific wear rate reduced by ≈ 62% and ≈ 47% respectively. The SEM investigation showed evidence of free graphite as a solid lubricant over the coated samples.

Laser Intensity Effect on Polyyne Synthesis in Liquid Hydrocarbons

Laser synthesis of polyyne molecules C2nH2 (n > 2) in liquid hydrocarbons is a complex process in which intense pulsed radiation decomposes the initial carbon-containing substance (the hydrocarbon solvent itself or the solid carbon particles in a suspension). Notwithstanding the fact that the mechanism of pulsed laser ablation in liquids (PLAL) is widely accepted, the effect of the laser parameters on laser-driven polyyne formation is still not understood in detail. Here, we report a study of the polyyne yield as a function of the laser field intensity and exposure dose. Several carbon-containing liquids, including pure n-hexane, pure ethanol, and graphite powder suspended in ethanol, were treated with tightly focused picosecond IR radiation (wavelength of 1064 nm, pulse duration of 10 ps). The synthesis rate was characterized by UV-vis optical absorption spectroscopy. The yields of the polyynes were found to vary in exact accordance with the value of the absorbed laser energy, following specific nonlinear or linear laws. The influence of the laser intensity on the partial concentration of polyynes in the solution was analyzed.

EFFECT OF GRAPHITE POWDER ADDITIVES ON MECHANICAL PROPERTIES AND ELECTRICAL CONDUCTIVITY IN BLAST FURNACE SLAG-BASED ALKALI-ACTIVATED MORTARS

In this study, the effect of graphite powder additive on mechanical properties and electrical conductivity of alkali-activated mortar samples produced using blast furnace slag was investigated. In the preparation of the mortar samples, graphite powder in (75) micron size was substituted at a rate of 0%-0.5-1%, 2% and 4% by weight of the binder. Sodium hydroxide and sodium silicate were used as activators in the mortar samples produced with Blast Furnace slag, and the samples were thermal cured at 110⁰C for 24 hours. Workability, unit weight, electrical conductivity, tendencies and compressive strength of all mortar samples that completed the curing period were determined. In addition, experiments were carried out to determine the water absorption and void ratios of the samples that gave the best results in the cementitious system activated with alkalis. The results obtained showed that the workability of the graphite powder was improved at 1% reinforcement rate in the mortar samples activated with alkalis, and it had a negative effect at the rates above 1%. It was understood that 1% graphite powder additive contributed positively to flexural and compressive strengths, while 4% graphite powder additive contributed provided the highest electrical conductivity.

Electrosynthesis and characterization of alloyed CdSxSe1−x ternary quantum dots

CdS, CdSe and CdSxSe1−x (x = 0.15, 0.35, 0.5, 0.65, 0.85) ternary quantum dots (QDs) were electrosynthesized in a cavity cell and aqueous medium, using 3-mercaptopropionic acid (MPA) as stabilizer. The electrochemical procedure was carried out by a paired electrolysis, where elemental sulfur and selenium were reduced in a graphite powder macroelectrode while a sacrificial cadmium rod was oxidized, giving the simultaneous generation of S2-, Se2- and Cd2+ ions for efficient production of the ternary QDs, in the S2-/Se2- ratio of choice. The CdSxSe1−x QDs were characterized by XRD, HRTEM, UV-Vis absorption and emission spectroscopies, and voltammetric analyses. XRD analysis showed lattice parameters of the cubic CdSxSe1−x nanoalloys with a linear drop tendency when the sulfide molar ratio increased in the crystalline structure. HRTEM analysis was used to determine nanoparticle sizes: 3.94 ± 0.70 nm (CdS), 4.23 ± 1.00 nm (CdS0.5Se0.5), and 4.12 ± 0.78 nm (CdSe), with interplanar distances of 0.348 nm, 0.341 nm, and 0.339 nm, respectively. The band gap energy (Eg opt) of the CdSxSe1−x QDs were determined by UV-Vis absorption spectroscopy: 2.42, 2.47, 2.53, 2.66, 2.63, 2.73 and 2.84 eV, respectively, showing a linear increasing according to the S2-/Se2- ratio. The same behavior was observed for the Eg Elect determined by cyclic and linear voltammetry analysis, presenting a nanoalloy nature of the ternary QDs electrosynthesized.

In-situ synthesis of TiC/Ti alloyed layer via pulsed Nd:YAG laser melting of Ti-6Al-4V titanium with preplaced carbon-based powder

The present research deals with fabricating an in-situ TiC/Ti alloyed layer on the Ti-6Al-4V titanium alloy through the preplacement of a mixture of graphite and nickel powders and subsequent pulsed Nd:YAG laser melting. The comprehensive effects of laser parameters, including scanning speed and energy density on the microstructural evolutions and hardness variations were investigated. It was found that the geometry of treated layers varied from 150 to 200 µm in thickness and 1200–1750 µm in width depending on the thickness of the preplaced layer and laser peak power. The promising results of X-ray diffraction patterns and scanning electron microscope observations manifested the formation of in-situ TiC and an increase in its content versus the energy density of the laser beam. The main mechanism of the in-situ formation of TiC in the matrix during laser irradiation was also discussed. The results indicated that the in-situ TiC phases had either dendritic or needle-like morphology. Laser parameters were crucial in establishing the TiC morphologies associated with temperature and chemical composition. The hardness values of the fabricated layers were directly proportional to the amount of TiC in the treated layers and varied from 1000 to 1400 HV0.3, which was nearly 3–4 times higher than that of the substrate.