Textural Characterization Research Articles

Curve smoothening for the analysis of fractal dimensions of blast-cleaned steel surface textures for tribological and adhesion interfaces

Abstract Fractal dimensions are increasingly used for the characterization of surface textures for tribological and adhesion applications. The resolution of 2D profiles acquired from various measurement methods can be adjusted via curve smoothing. It is still unclear whether curve smoothing would notably affect the estimated fractal dimensions. In this communication, 2D profiles of twelve blast-cleaned surface settings were derived by means of a data manipulation software, including a curve smoothing procedure. The fractal dimensions were estimated, and Design of Experiments was applied to analyze the relationships. Factors included abrasive type, preparation grade, roughness, and curve smoothing. Analysis of Variance indicated that the contribution of curve smoothing to the regression model was as low as 1.0%. Therefore, for blast-cleaned substrates, curve smoothing effects can be neglected with respect to the contributions of roughness and abrasive type, when estimating the fractal dimensions.

The Value of Fractal Analysis in Ultrasound Imaging: Exploring Intricate Patterns

Fractal analysis is a mathematical approach employed to study and describe complex patterns and structures across various disciplines, including mathematics, physics, computer science, biology and finance. Introduced by mathematician Benoit Mandelbrot in the 1970s, fractals are intricate, self-similar patterns that repeat at different scales, exhibiting consistent structures upon magnification or reduction. This analysis involves generating fractals through iterative processes or recursive equations, resulting in highly detailed and complex formations. Fractal analysis enhances medical images by removing noise while preserving details and improving diagnostic quality in magnetic resonance and computed tomography scans. However, there is a lack of comprehensive studies on its application in ultrasound imaging, prompting this narrative review to investigate its use and methodology in this context. Selected papers on the use of fractal analysis in ultrasound imaging were analyzed. Out of 186 records screened, 60 duplicates were removed and 28 were discarded. The text content of 98 potentially eligible papers was checked, with 65 not meeting inclusion criteria. Finally, 33 studies were included in the review. Fractal analysis enhances ultrasound imaging by providing detailed tissue texture characterization, aiding in the diagnosis of conditions like breast and lung cancer, osteoporosis and hypertensive disorders in pregnancy. It quantifies biological structure complexity and improves diagnostic accuracy and reliability. This technique supports clinicians in making informed decisions by offering critical insights into various medical conditions.

Development and Application of an Advanced Percolation Model for Pore Network Characterization by Physical Adsorption.

Physical adsorption is one of the most widely used techniques to characterize porous materials because it is reliable and able to assess micro- and mesopores within one approach. Challenges and open questions persist in characterizing disordered and hierarchically structured porous materials. This study introduces a pore network model aimed at enhancing the textural characterization of nanoporous materials. The model, based on percolation theory on a finite-sized Bethe lattice, includes all mechanisms known to contribute to adsorption hysteresis in mesoporous pore networks. The model accounts for delayed and initiated condensation during adsorption as well as equilibrium evaporation, pore blocking, and cavitation during desorption. Coupled with dedicated nonlocal-density functional theory kernels, the proposed method provides a unified framework for modeling the entire experimental adsorption-desorption isotherm, including desorption hysteresis scans. The applicability of the method is demonstrated on a selected set of nanoporous silica materials exhibiting distinct types of hysteresis loops (types H1, H2a, H1/H2a, and H5), including ordered mesoporous silica networks (KIT-6 and SBA-15/MCM-41 hybrid silica with plugged pores) and disordered mesoporous silica networks (hierarchical meso-macroporous monolith and porous Vycor glass). For all materials, a good correlation is found between calculated and experimental primary isotherms as well as desorption scans. The model allows us to determine key pore network characteristics such as pore connectivity and pore size distributions as well as a parameter correlated with the impact of pore network disorder on the adsorption behavior. The versatility and enriched textural insights provided by the proposed novel network model allow for a comprehensive characterization previously inaccessible and hence will contribute to further advancement in the textural characterization of novel nanoporous materials. It has the potential to provide important guidance for the design and selection of porous materials for optimizing various applications, including separation processes such as chromatography, heterogeneous catalysis and gas and energy storage.

Landmark-aware autonomous odometry correction and map pruning for planetary rovers

Planetary rover autonomous localization is paramount for a planetary surface exploration mission. However, existing methods demonstrate limited localization accuracy, mostly due to the unstructured texture characterization of planetary surface. In response, this study presents a novel Neural Radiance Field (NeRF) driven visual odometry correction method that allows for high-precision 6-DoF rover pose estimation and local map pruning. First, an innovative image saliency evaluation approach, combining binarization and feature detection, is introduced to meticulously select landmarks that are conducive to rover re-localization. Subsequently, we conduct 3D reconstruction and rendering of the chosen landmarks based on a-priori knowledge of planetary surface images and their Neural Radiance Field (NeRF) models. High-precision odometry correction is achieved through the optimization of photometric loss between NeRF rending images and real images. Simultaneously, the odometry correction mechanism is employed in an autonomous manner to refine the NeRF model of the corresponding landmark, leading to an improved local map and gradually enhanced rover localization accuracy. Numerical simulation and experiment trials are carried out to evaluate the performance of the proposed method, results of which demonstrate state-of-the-art rover re-localization accuracy and local map pruning.

Sintering process optimization of the additively manufactured pure copper parts through the metal paste deposited process

The fabrication process, sintering cycles through two sintering methods, microstructural and texture characterization, mechanical properties, and electrical conductivity of metal paste-deposited copper parts were investigated in this study. In the first condition, samples were air-debinded for carbon content removal followed by a sintering cycle. A sintering profile with the maximum sintering temperature and time of 1080 °C and 1 hr. was implemented after performing the air-debinding cycle at 250 °C for 2 hrs. In the second condition, samples were sintered in the environment of copper oxide for carbon removal in the early stages of the sintering cycle, i.e., 1070 °C for 1 hr and 1080 °C for 1, 2, and 3 hrs. The microstructural observations revealed coarser grains in the air-debinded samples, perhaps due to additional generated heat during carbon oxide formation, which may produce destructive effects on the boundary (HAGBs, twins, and CSL) volume and densification behavior of copper parts. However, through the second method, much finer grains and higher densities of boundaries were detected in the microstructure. Despite the significant effect of sintering conditions on the microstructure, texture interpretations revealed minor changes in the pole figures for different situations. Using the second sintering method and owing to the less carbon content and based on the density of the boundaries and their configurations, higher electrical conductivity (98.4±1.3 % IACS) was recorded by sintering the green parts. The comparison between the data from this study with other parts printed through other additive manufacturing techniques demonstrated a superior electrical conductivity level and acceptable balance between strain and strain notably with the sample sintered for 3 hrs.

Development, Chemical Composition, Textural Characterization and Sensory Acceptability of Oyster or Big Cup Mushroom Incorporated Chicken Meatloaves

ABSTRACT This study examined chemical and textural attributes as well as sensory acceptability of chicken and mushroom (oyster and big cup) meatloaves. Simplex lattice design was used to create eight formulations of chicken-oyster mushroom (COM) and chicken-big cup mushroom (CBM), respectively. The samples were analyzed for proximate and mineral composition, crust and crumb color, pH, and texture. The optimized meatloaf samples were subjected to sensory evaluation. The optimized chicken-mushroom ratios were determined to be 83.82% chicken meat and 16.18% oyster mushroom, and 84.78% chicken meat and 15.22% big cup mushroom. Chicken-oyster meatloaf was rated as more acceptable than chicken-big cup meatloaf and control samples in all aspects by sensory panelists. There was no significant difference (p > 0.05) between the sensory attributes, except for aroma (p < 0.05). The study concluded that inclusion of oyster or big cup mushroom in chicken meatloaf had significant influence (p < 0.05) on nutritional, color, pH, and texture characteristics of chicken meatloaf.

Reduction of 2,4-dichlorophenoxy acetic acid herbicide toxicity from aqueous media by adsorption: Experimental and theoretical study using DFT method

This work studies the possibility of reducing the toxicity of water laden with 2,4-dichlorophenoxy acetic acid (2,4-D) using a commercial activated carbon (AC). Multiple structural and textural characterization techniques including Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM/EDS), point of zero charge (pHzpc) determination, Boehm titration, iodine number, Methylene blue index, and BET analysis measurements were performed on the commercial AC. Various parameters affecting adsorption were studied and well-known isotherms models in their linear and non-linear forms were applied for fitting equilibrium data. The kinetic data was analyzed using intraparticle diffusion, pseudo-first and second-order kinetic models. Density functional modeling (DFT) of 2,4-dichlorophenoxyacetic acid was used to investigate the origin of the reactivity. The AC surface area was found to be 1017 m2⋅g−1. A contact time of 30 min, an AC dose of 4 g⋅L−1 and a pH of 6.2 resulted in a maximum adsorption capacity of 235.55 ± 6.43 mg⋅g−1. The thermodynamic study revealed that the adsorption process was physical, spontaneous and endothermic. The adsorption process was governed by second-order kinetics and controlled by intraparticle diffusion.

A Feature of the Horizontal Directional Solidification (HDS) Method Affects the Microstructure of Al2O3/YAG Eutectic Ceramics

The solidification processes of two compositions, hypereutectic (21.0 mol% Y2O3–79.0 mol% Al2O3) and eutectic (18.5 mol% Y2O3–81.5 mol% Al2O3), were used via the horizontal directional solidification (HDS) method to produce two ingots with dimensions of 317 × 220 × 35 mm and 210 × 180 × 35 mm, respectively. The first ingot was heterogeneous and characterized by a two-layer structure with an expressed horizontal boundary, which is parallel to the solidification direction (an experimental fact observed for the first time), separating eutectic-type ceramics in the upper layer from the lower one containing the YAG dendrites. Considering the heat transfer feature characteristic of the HDS method and its action during the solidification of materials scattering thermal radiation, an explanation of the occurrence of such structure has been proposed. On this basis, the solidification parameters of the second ingot, providing its homogeneous structure, were selected. Characterization of the crystallographic texture and microstructure of both ingots revealed the advantage of the second solidification processing conditions.

Understanding of the effect of concentration of green polysaccharide-based TiO2 for photoelectrochemical, photocatalytic, and antibacterial properties

Composites formed by TiO2/babassu mesocarp were synthesized by the sol-gel method with a percentage variation of 3 % and 5 % (w/v) called 3BBT and 5BBT, respectively. The materials were characterized by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), UV–Vis Diffuse Reflectance Spectroscopy, and surface area was calculated by the Brunauer–Emmett–Teller method (BET). Electrochemical studies were carried out, and photocurrent data was obtained as a function of the variation in gallic acid concentration and applied potential. The photocatalytic efficiency of the material was investigated by the degradation of the Methylene Blue (MB) dye under light. The antimicrobial activity of the materials was tested on Gram-positive and Gram-negative strains. XRD showed that the composites obtained are in the anatase crystallographic phase, and the increase in the percentage of babassu mesocarp influenced the reduction of peak intensity and crystallite size. The microscopy showed a more porous aspect of the 3BBT material and a denser aspect of the 5BBT material. It was confirmed by textural characterizations, which showed reduced pore volume and specific surface area of 5BBT compared to 3BBT. Increasing the percentage of polysaccharides caused a reduction in the band gap energy of TiO2 (Eg = 2.90 eV and Eg = 2.47 eV for 3BBT and 5BBT, respectively). The electrochemical study showed that the composites could detect gallic acid, providing increased sensitivity according to the increased applied photocurrent. They also showed good precision for the photoelectrochemical measurements, as verified in the repeatability test (2.66 % and 3.68 % RPD for 3BBT and 5BBT, respectively). The 3BBT showed greater photocatalytic capacity, discoloring 63.4 % of the MB dye in 120 min under light and electrons are the main species involved in photocatalytic activity demonstrated by 3BBT. Antibacterial tests indicated that the 5BBT material exhibits a greater capacity to inhibit E. coli and S. aureus bacteria.

Carbon-containing pyrite spherules: mineral biosignatures in black smokers?

Abstract. Sulfide- and sulfate-rich hydrothermal vents are involved in Earth's major geochemical cycles. An outstanding scientific question consists of finding out whether certain minerals found in hydrothermal chimneys are influenced more or less directly by microorganisms living at high temperatures (thermophiles or hyperthermophiles) in these environments. Here we report the morphological, textural and chemical characterization of pyrite crystals collected across a section of a chimney from the Trans-Atlantic Geotraverse hydrothermal site, sampled from the inner, hotter portion to the external, cooler portion, providing a promising approach to the search for hyperthermophilic biosignatures. The internal and middle portions of the chimney mainly harbour cube-shaped pyrite containing low quantities of hydrocarbons and thermally matured organic compounds. In contrast, the samples from the external portion contain pyrite spherules composed of a mosaic of slightly disoriented domains that include large amounts of organic material chemically consistent with thermally matured biogenic organic compounds. These characteristics make them comparable but not identical to pyrite spherules produced in the laboratory in the presence of hyperthermophilic archaea of the order Thermococcales. Differences include larger crystalline domains and more thermally matured organic compounds. Such features could be consistent with the thermal transformation of pyrite spherules produced by (or at least in the presence of) living cells. However, it remains impossible to completely rule out an abiotic origin without further isotopic investigation and experimental studies on the abiotic production of pyrite spherules in the presence of organic compounds and under hydrothermal conditions.

Synthesis and enhanced H2S gas sensing performances of Co-doped NiO@g-C3N4 heterocomposites

Metal doping is an efficient approach to improve H2S gas sensing performances, but the metal-doped NiO is still faced poor recovery capability at low working temperature. Herein, Co-doped NiO@g-C3N4 heterocomposites were constructed firstly via a simple solid phase reaction. Texture characterizations indicate that Co-doped NiO@g-C3N4 heterocomposites with the architecture of hierarchical microspheres show high specific surface areas and rich surface oxygen vacancies. The gas-sensitive measurements exhibit that the response value of the heterocomposites with g-C3N4 content of 30 wt% (Co-NiO@g-C3N4-3) increases to 45 toward 20 ppm H2S gas at 172 °C, which is about 1.8 times of Co-NiO (23), as well as response/recovery times decreased to ca. 100/130 s. Besides, excellent repeatability, stability and selectivity of Co-NiO@g-C3N4-3 sensors are obtained. The improved H2S gas sensing performances of Co-NiO@g-C3N4 heterocomposites is mainly contributed to the formation of nano-heterojunctions, which promotes electron accumulation at nano-heterojunctions near Co-NiO, facilitates O2 molecules adsorption on the material surface and accelerates the resistance change of the sensors, resulting the enhanced gas sensing performances.

Adsorption of Uranium (VI) From Aqueous Solution Using Melamine Formaldehyde Organo Clay Nanocomposite Foam as a Novel Adsorbent

Uranium is a toxic radioactive element and is usually found in the environment in hexavalent form. It has become necessary to remove uranium, which can be released into the environment in excessive amounts through nuclear industrial activities, from access waters. Melamine formaldehyde/organo clay nano composite foam (MFCNCF) was prepared as a novel adsorbent by hardening with thermal treatment. Structural, crystallographic textural and surface morphological characterization of the prepared adsorbent was made by Fourier transform infrared spectrophotometry (FTIR), X-Ray diffraction (XRD), Scanning electron microscopy (SEM) and High-resolution transmission electron microscopy (HRTEM) analyses. This study aimed to investigate the adsorption of U(VI) from aqueous solutions by MFCNCF and its dependence on various variables, such as initial uranium concentration, adsorption time, adsorbent dosage, initial pH, and temperature. Additionally, its adsorption isotherm analysis and adsorption kinetics and thermodynamics were also examined. For this purpose, batch adsorption experiments were carried out and the equilibrium concentration of U(VI) in the aqueous solution was measured with a UV-Vis spectrophotometer at a wavelength of 433 nm, which corresponds to its maximum absorptivity. The results regarding adsorption kinetics showed that 30 min was sufficient to reach adsorption equilibrium and the data showed a high fit to the pseudo-second-order kinetic model. Isotherm analysis also revealed a high fit of the data to the Type III isotherm and the Halsey model. Based on these fits, an adsorption mechanism involving two regions (electrostatic and complex formation) is proposed for the current adsorption system. The adsorption isosteric enthalpy and entropy values for the first and second regions were found to be −5.35 and 2.02 kJ/mol and −16.98 and 6.40 J/mol, respectively. The experimental results showed that the prepared nanocomposite foam adsorbent is an effective and potential alternative for the effective removal of U(VI) from aqueous solutions.

Tomato seed fractions enriched muffins: functional, textural, and qualitative characterisation

SummaryThe current study was undertaken to investigate the use of tomato seed oil (TSO) and defatted tomato seed meal (DTSM) individually and in combination for muffin preparation in an effort to utilise the fruit waste generated during food processing and harness its nutritional potential. The incorporation of DTSM and TSO at 0–25% led to a significant increase in the baking yield and weight of muffins, with a more pronounced effect in the case of DTSM‐incorporated muffins. Based on organoleptic evaluation, muffins with incorporation of DTSM and TSO at 20% and 15%, respectively, were most acceptable. Therefore, muffins (DTSM 20 + TSO 15) were prepared with DTSM and TSO replacement at 20% and 15%, respectively. The combined effect of DTSM and TSO resulted in a dietary fibre increase of 61.57% as compared to the control (wheat flour and margarine‐based muffins). As per texture profile analysis, the addition of DTSM led to a significant decrease in hardness, whereas a rise was noted for TSO‐incorporated muffins. Storage studies of muffins for 7 days in low‐density polyethylene pouches indicated no significant degradation in quality parameters. The results obtained in the study confirmed the efficient utilisation of tomato seed fractions for the preparation of nutritionally enriched muffins.

Crystallization kinetics as a tool to fine-tune the catalytic activity of Na-LTA zeolite precursors in the transesterification of glycerol to glycerol carbonate

Glycerol carbonate is a versatile molecule used as a fuel additive and a chemical building block. It is a prominent route for glycerol valorization, improving the biodiesel production chain. This base-catalyzed reaction can be carried out using sodium-type zeolites if accessibility to the basic sites is ensured. Herein, we report a facile strategy to fine-tune the number and access to basic sites of Na-LTA zeolite precursors via monitoring the crystallization kinetics of the microporous material. It is demonstrated that an optimal glycerol to glycerol carbonate conversion is obtained when using the solid obtained at the beginning of the crystallization (90 min at 100 °C of hydrothermal step). Textural and spectroscopy characterization reveals that semicrystalline material presents many basic aluminate anions in a very open structure, allowing facile access to glycerol and propylene carbonate. Moreover, it is shown that this catalyst is stable in four successive reaction cycles and active in different reactions conditions

Multi-parameterised surface texture characterisation for ultra-precision machined surfaces

Abstract In surface metrology, the multi-parameterised characterisation of surface texture measurement is beneficial not only for surface quality evaluation but also for manufacturing process inspection. To bridge this gap for ultra-precision machined surfaces, a white light interferometer was firstly employed for measuring surface texture generated by orthogonal ultra-precision machining experiments. Next, surface texture was filtered by the zero-order Gaussian regression filter to the limited scale bandwidth. Then, twenty-one surface texture parameters were calculated based on seventy-five S-L surfaces according to the ISO 25178-2. Finally, the outlier effect of surface measurement was investigated by the 95%-99% rule and the Spearman correlation coefficient matrix was proposed to determine their statistical correlation. The results revealed that most of the height parameters (Sp, Sv, Sz, Ssk, and Sku), several function and related parameters (Vmp, Vvv, Spk, and Svk), and the spatial parameter (Str) and hybrid parameter (Sdr) presented a strong sensitivity to the outlier effect. The height parameters (Sa, Sq, Sp, Sv, and Sz), the function and related parameters (Vmp, Vmc, Vvv, Vvc, Spk, Svk, and Sk), and the spatial parameters (Sdq and Sdr) showed a strong correlation to each other, while the miscellaneous parameter Std had a weak correlation to the other parameters. This study provides a systematic multi-parameterised surface texture characterisation for ultra-precision machined surfaces to promote the advancement of nanotechnology and nanometrology.

A Facile Method to Transform Pickled Olive Wastes Into Sulfur-Doped Carbon for Sodium-Ion Battery Electrode.

This work provides a novel, low-cost, and effective method to prepare disordered carbon materials for advanced sodium-ion batteries using biomass. A large amount of olive stone waste is yearly produced in the world, and it could be re-used for fine applications other than fuel for heat production. After treatment with sulfuric acid solution and carbonization process, wastes of olive stone are efficiently transformed into optimized carbon electrode material. XRD, XRF and XPS, electron microscopy, and physical gas adsorption are used for the compositional, microstructural, and textural characterization of the carbons. During the synthesis, impurities are removed, C-S links are formed and micropores pores are created. Sulfuric acid acts like S-dopant. The latent pores, or pores closed to nitrogen, can be found using CO2 adsorption, and are very suitable for accommodation for sodium. The results reveal that the reversible capacity is raised from ca. 200 mAh g-1 to ca. 250 mAh g-1 for the carbon obtained through treatment with sulfuric acid. The improved electrochemistry is the result of the s-doping and the porosity.

On the effect of material density in dimensional evaluations by X-ray computed tomography of metal-polymer multi-material parts

An important aspect to consider in the evaluation of parts and assemblies by X-ray computed tomography (XCT) is the attenuation coefficient of the different materials involved, which are directly related to their density; depending on this coefficient, the X-ray penetration varies and, therefore, varies the contrast between different materials and with the background. This becomes more critical in those assemblies in which materials are characterized by a high difference in density, where the lighter material could be difficult to be characterised. In this paper, the effect of the presence of metals in the dimensional evaluation of polymeric geometries (having lower density than the metal parts) is studied, to evaluate the errors caused in dimensional measurements of different geometries and surface texture characterization. Based on a common geometry, four scenarios have been experimentally tested with variations of metal amount, in which macro geometries (precision spheres made by different polymers) and micro geometries (inclined ramps manufactured by fused deposition modelling (FDM)) have been characterised. Results show errors in the surface determination of the polymeric features directly related to the presence of metal: a high amount of steel makes significantly difficult to accurately determine the interface between background and material due to the noise and artifacts created, while aluminium has less influence on the irregularities of the features extracted. This effect is more evident for polymers with lower density due to the higher difference. Numerically, most affected parameters are those sensible to variations in surface determination, such as spheres’ form error and ramps’ maximum surface texture (Sz), while more solid features as spheres’ diameters, distances and ramps’ average surface texture (Sa and Sq) remain more stable. In conclusion and to sum up, it has been found that the quantity of metal present in assemblies made of polymeric and metallic materials is correlated with distortions in the dimensional evaluation of polymeric features by XCT.

Quality, Textural, Bioactive, Molecular and Chromatographic Characterization of Citrus Pseudolimon from Different Geographical Locations in India

Quality, Textural, Bioactive, Molecular and Chromatographic Characterization of Citrus Pseudolimon from Different Geographical Locations in India

Hydrogen Storage Using Platinum‐Supported Ceria Dispersed on Activated Carbon

ABSTRACTIn the current work, carbon materials were used in the hydrogen adsorption process, specifically as carbons doped with platinum dispersed on ceria. The textural characterization results of the prepared samples and the starting carbon showed the presence of both micro‐ and mesopores. On the other hand, it has been observed that the specific areas were inversely proportional to the CeO2 loading. In addition, the amount of adsorbed hydrogen increased after doping the carbon with platinum and, even more, when the carbon was doped with Pt dispersed on ceria (2.2 mg/g at 25°C and 30 bar). However, there was a ceria optimum from which the adsorption capacity decreased (10% wt). The results of temperature‐programmed desorption (TPD) of hydrogen indicated a high affinity between Pt and H2 that enhanced H2 adsorption process by establishing chemical bonds between the metal particles and H2. Precisely, the presence of metallic Pt particles dispersed on ceria considerably promotes the spillover process of hydrogen on carbon. This can be confirmed by hydrogen adsorption–desorption isotherms, that showed that complete desorption of chemisorbed hydrogen required an increase of temperature.

Adsorption of methane by modified-biochar aiming to improve the gaseous fuels storage/transport capacity: process evaluation and modeling.

The CH4 storage by adsorption on activated carbons for natural gas handling has gained interest due to the appearance of lightweight materials with large surface areas and pore volumes. Consequently, kinetic parameters estimation of the adsorptive process can play a crucial role in understanding and scaling up the system. Concerning its versatility, banana peel (BP) is a biomass with potential for obtaining different products, such as biochar, a solid residue from the biomass' thermal decomposition of difficult disposal, where through an activation process, the material porous features are taken advantage to application as adsorbent of gaseous substances. This research reported data for the CH4 adsorption kinetic modeling by biochar from BP pyrolysis. The activated biochar textural characterization showed particles with fine mesoporous structure (pore diameter ranging between 29.39 and 55.62Å). Adsorption kinetic analysis indicated that a modified pseudo-first-order model was the most suitable to represent the experimental data, with equilibrium adsorption of 28mgg-1 for the samples activated with 20.0% vol wt.-1 of H3PO4 and pyrolysis at 500°C. The equilibrium constant was consistent with the Freundlich isotherm model, suggesting a physisorption mechanism, and led to a non-ideal, reversible, and not limited to monolayer CH4 adsorption.