Microscopy-energy Dispersive X-ray Spectroscopy Research Articles

Visualising microstructural dynamics of titanium aluminium nitride coatings under variable-temperature oxidation

Understanding the link between titanium-aluminium nitride’s (Ti1-xAlxN) physicochemical properties and structural dynamics during operation is essential to designing and fabricating advanced ceramic coatings. Here, we directly visualise the oxidation of Ti1-xAlxN (for x = 0, 0.18, 0.44, & 0.67) coatings from 100 to 1000 °C using environmental transmission electron microscopy (ETEM) imaging and energy dispersive X-ray spectroscopy (EDX) analysis. The high-frame-rate ETEM movies show that oxidation in TiN proceeds at the grain boundaries and cracks; in contrast, Ti1-xAlxN coatings transform from large as-deposited grains into oxide nanoparticles. Moreover, high-resolution ETEM imaging show the presence of anatase TiO2 at the early stages of oxidation across all compositions. Above ∼ 850 °C, the oxide nanoparticles grow through crystal merging, diffusion and recrystallisation to form rutile TiO2. The EDX elemental maps coupled with secondary electron imaging reveal a uniform TiO2 sublayer decorated with increasing coverage of Al2O3 particles for x = 0.18 to 0.44. In contrast, coatings with x = 0.67 reveal a complete in-plane phase separation of Al- and Ti-oxides, which can rationalise their decreasing long-term oxidation resistance. Finally, the study provides unique insight into the real-time structural dynamics underpinning the oxidation resistance of Ti1-xAlxN coatings.

Theoretical and experimental investigation of ash-related problems during coal co-firing with different types of biomass in a pulverized coal-fired boiler

Biomass waste can be utilized as a mixed co-firing fuel in power plants to reduce net carbon emissions. However, understanding the characteristics of biomass and its blend before being applied to actual power plants is required. Adding biomass to the existing power plant fuel may cause problems such as slagging and fouling due to ash deposits, affecting the plant's lifetime and operational and maintenance costs. This study comprehensively investigated the slagging and fouling potential when co-firing coal with four types of biomasses by combining theoretical calculations and experimental methods. The experimental method included combustion tests and a series of ash investigations, such as probe observation, scanning electron microscopy–energy dispersive X-ray spectroscopy, and X-ray diffraction. The results show that co-firing of coal with 25% of either palm oil empty fruit bunch–frond or wood chip yields a similar performance concerning combustion characteristics, gas emissions, ash deposits, and ash mineralogy. The addition of 25% rice husk needs consideration of soft scratches on the surface probe and the amount of ash deposit. The results also suggest that a co-firing with less than 25% solid recovered fuel needs further investigation to mitigate the slagging and fouling tendency. Finally, these findings are important for clarifying several types of biomasses as potential co-firing fuels for pulverized coal-fired power plants.

Occurrence Relationship between Sodium and Maceral Groups in Subbituminous Coal: A Case Study on Zhundong Coal and Shenfu Coal

The occurrence characteristics of sodium and its potential relationship with macerals in Zhundong coal, as well as in Shenfu coal with average sodium levels, are investigated in this study. A new five-step sequential extraction method was first conducted for determination. The occurrence status of sodium and its related macerals in samples was determined by microscope and SEM–EDS (scanning electron microscope–energy dispersive X-ray spectroscopy). Soluble sodium salts (H2O-Na) make up the primary proportion of sodium in Zhundong coal, at approximately 50%, while various sodium species are distributed in Shenfu coal with nonobvious differences. Inertinite contains more sodium than vitrinite does in both coals, and the highest enrichment degree of sodium was discovered in inertinite from Zhundong coal, which presented primarily as NaCl crystals (H2O-Na) in fusinite cells, with a local weight percentage of over 15%. More specifically, H2O-Na and insoluble Na both tend to enrich in fusinite. Additionally, it is found that maceral-rich products can be gathered using triboelectrostatic separation, and a portion of sodium can thus be removed from the coal by removing inertinite. This study may provide new insights and references regarding sodium removal from Zhundong coal.

Effect of Alkaline Pretreatment on the Fuel Properties of Torrefied Biomass from Rice Husk

Lignocellulosic biomass from rice husk (RH) is a renewable resource for fuel production, but it could pose ash-related challenges. This work focused on investigating the effects of pretreatment at different sodium hydroxide (NaOH) concentrations (i.e., 0.0, 0.25, 0.50, 0.75 and 1.00 M) on the calorific values and ash contents of treated RH products, and also finding the optimal torrefaction conditions. The results showed that alkaline pretreatment by sodium hydroxide (NaOH) reduced the ash content in the RH samples by over 85 wt%. Due to its relatively excellent calorific values and low ash content, the RH sample with 0.25 M NaOH pretreatment (i.e., RH-25) was chosen as a starting feedstock in the subsequent torrefaction experiments as a function of 240–360 °C for holding time of 0–90 min. In addition, the surface properties by scanning electron microscopy—energy dispersive X-ray spectroscopy (SEM-EDS) and Fourier-transform infrared spectroscopy (FTIR) were also used to observe the elemental compositions preliminarily. Based on the fuel properties of the torrefied RH products, the optimal torrefaction conditions can be found at around 280 °C for holding 30 min. As compared to the calorific value of the RH-25 (i.e., 18.74 MJ/kg) and its mass yield (i.e., 0.588), the calorific value, enhancement factor and energy yield of the optimal product were 28.97 MJ/kg, 1.55 and 0.91, respectively. Although the resulting product has a high calorific value like coal, it could have slight potential for slagging and fouling tendency and particulate matter emissions due to the relatively high contents of silicon (Si) and sodium (Na), based on the results of EDS and FTIR.

Efficient removal of Cd2+ by diatom frustules self-modified in situ with intercellular organic components

The organic modification of three-dimensional porous diatom frustules (biosilica) and their fossils (diatomite) is promising in heavy metal adsorption. However, the preparation of such materials involves complex processes, high costs, and environmental hazards. In this study, organic-biosilica composites based on in situ self-modification of diatoms were prepared by freeze-drying pretreatment. Freeze-drying resulted in the release of the intercellular organic components of diatoms, followed by loading on the surface of their diatom frustules. The bio-adsorbent exhibits outstanding Cd2+ adsorption capacity (up to 220.3 mg/g). The adsorption isotherms fitted the Langmuir model and the maximum adsorption capacity was 4 times greater than that of diatom biosilica (54.1 mg/g). The adsorption kinetics of Cd2+ was adequately described by a pseudo-second-order model and reached equilibrium within 30 min. By combining focused ion beam thinning with transmission electron microscopy–energy dispersive X-ray spectroscopy, the internal structure of the composite and the Cd2+ distribution were investigated. The results showed that the organic matter of the composite adsorbed approximately 10 times more Cd2+ than inorganic biosilica. The adsorption mechanism was dominated by complexation between the abundant organic functional groups (amide, carboxyl, and amino groups) on the surfaces of composite and Cd2+. The bio-adsorbent was demonstrated to have wide applicability in the presence of competitive cations (Na+, K+, Ca2+, and Mg2+) and under a wide range of pH (3–10) conditions. Thus, the self-modification of diatoms offers a promising organic–inorganic composite for heavy metal remediation.

Compositional tuning of gas-phase synthesized Pd-Cu nanoparticles.

Bimetallic nanoparticles have gained significant attention in catalysis as potential alternatives to expensive catalysts based on noble metals. In this study, we investigate the compositional tuning of Pd-Cu bimetallic nanoparticles using a physical synthesis method called spark ablation. By utilizing pure and alloyed electrodes in different configurations, we demonstrate the ability to tailor the chemical composition of nanoparticles within the range of approximately 80 : 20 at% to 40 : 60 at% (Pd : Cu), measured using X-ray fluorescence (XRF) and transmission electron microscopy energy dispersive X-ray spectroscopy (TEM-EDXS). Time-resolved XRF measurements revealed a shift in composition throughout the ablation process, potentially influenced by material transfer between electrodes. Powder X-ray diffraction confirmed the predominantly fcc phase of the nanoparticles while high-resolution TEM and scanning TEM-EDXS confirmed the mixing of Pd and Cu within individual nanoparticles. X-ray photoelectron and absorption spectroscopy were used to analyze the outermost atomic layers of the nanoparticles, which is highly important for catalytic applications. Such comprehensive analyses offer insights into the formation and structure of bimetallic nanoparticles and pave the way for the development of efficient and affordable catalysts for various applications.

Fabrication and characterization of RF magnetron sputtered composite MoS2 and ZrN coatings on Ti3SiC2 max phase for space applications

The lubrication effect of solid-based materials has been recognized for centuries, but their use as lubricants dates back to only about 50 years. Solid lubricants are used in applications where parts operate under severe operating conditions such as extreme temperatures and very high vacuum. Solid lubricants replace liquid based lubricants for operation under extreme environmental conditions that are beyond the capability of a liquid-based lubricant such as high or very high vacuum, high and cryogenic temperatures, radiation, corrosive gases, and fretting wear. Applications such as space mechanisms, satellites, space vehicles, turbopumps, nuclear reactors, refrigeration plants, etc are examples of such operating conditions. In this research, nano scale composite coatings of MoS2with varied proportions of ZrN (5%, 10% and 20%) were deposited on Ti3SiC2 Max phase substrate using Physical Vapour Deposition (PVD). The PVD technique used was the RF magnetron sputtering process. Material characterization was carried out using Field Emission Scanning Electron Microscope (FESEM) Spectroscopy and Energy Dispersive X-Ray Spectroscopy (EDS). Addition of ZrNis observed to reduce the porosity of the self-lubricating MoS2 coating.

Effect of pretreatment by shotblasting prior to lubrication for cold forging

Effect of pretreatment by shotblasting to workpieces before lubricating of a non-chemical conversion lubricant in cold forging was examined by making several surfaces with different topographies, using wet shotblasting. Backward-cup extrusion test estimated the performance of the pretreatment. This test provides extremely large surface expansion to bring severe tribological conditions. After the tests, the insides of the cup-like workpieces were observed with scanning electron microscope and surface-analyzed energy dispersive X-ray spectroscopy to measure the distributive amount of the lubricant on the workpiece. The pretreated surface resulting large aspect ratio (Ra / RSm) raised the potential of lubrication performance. Especially, the surface treated with angular shaped media indicated higher potential to improve anti-galling performance.

Rapid screening of wood and leaf tissues: investigating silicon-based phytoliths in Populus trichocarpa for carbon storage applications using laser-induced breakdown spectroscopy and scanning electron microscopy–energy dispersive X-ray spectroscopy

Phytoliths, which are noncrystalline particles of amorphous silica that form inside plant cells, contribute to the global carbon cycle through their ability to occlude organic carbon.

Novel research on polyamide 11 nanocomposites reinforced by Titania nanoparticle deposited jute fibres

The combination of jute fibres and polyamide 11 (PA11) to produce full biocomposites is expectance of scientists due to many benefits of both these materials such as high mechanical performances and environmentally friendly behaviors. Unfortunately, there is scarce published research on these bicomposites uptil now. In order to improve the interfacial interaction and adhesion between jute fibres and PA11 resin matrix, an important key in the fabrication of the composites. In this study, a combination of alkaline treatment and Tetraisopropyl orthotitanate (Tip) modification was employed to modify the surface of jute fibres. The deposition or grafting of TiO2 nanoparticles was proved by using Fourier transform infrared (FTIR), scanning electron microscopy (SEM) observations and energy dispersive X-ray spectroscopy (EDS/EDX) analysis. The improvement of the interfacial interaction and adhesion between surface modified jute fibres and PA11 resin as well as high performances (mechanical properties, thermal oxidative and water absorption stability) of obtained biocomposites were also clarified.

Catalytic Oxidative Desulfurization of Dibenzothiophene Utilizing Composite Based Zn/Al Layered Double Hydroxide

In this study, the Zn/Al-TiO2 and Zn/Al-ZnO was successfully synthesized. The catalysts were characterized by X-ray Diffraction (XRD), Fourier Transform Infra Red (FTIR), and Scanning Electron Microscope—Energy Dispersive X-ray Spectroscopy (SEM-EDS). The typical diffraction peaks of Zn/Al-LDH, TiO2, and ZnO still appear in the Zn/Al-TiO2 and Zn/Al-ZnO composites, indicating that the composite preparation did not change the form of precursors. FTIR spectra of Zn/Al-TiO2 and Zn/Al-ZnO showed absorption band at 3448, 1627, 1381, 832, 779, and 686 cm-1. The catalysts have an irregular structure where the percent mass of Ti and Zn on the composite at 10.6% and 55.6%, respectively. The acidity of Zn/Al-LDH composite increased after being composed with TiO2 and ZnO. The percentage conversion dibenzothiophene on Zn/Al-ZnO, Zn/Al-TiO2, ZnO, Zn/Al-LDH, and TiO2 was 99.38%, 96.01%, 95.36%, 94.71%, and 91.92%, respectively. The heterogeneous systems of catalytic reaction was used for reusability. After 3 cycles catalytic reactions at 50 oC for 30 min, the percentage conversion of dibenzothiophene on Zn/Al-LDH, TiO2, ZnO, Zn/Al-TiO2, and Zn/Al-ZnO were 77.42%, 83.19%, 82.34%, 84.91%, and 89.71 %, respectively. The composites of Zn/Al-TiO2 and Zn/Al-ZnO have better reusability test than Zn/Al-LDH, TiO2, and ZnO, which proofing that Zn/Al-TiO2 and Zn/Al-ZnO have a stable structure. Copyright © 2022 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Effective Approach by Computational Chemical Prediction and Experimental Verification to Elucidate SEI Formation Mechanism in LiPF6-, LiFSI-, and LiBF4-Containing Electrolyte Solutions

Solvation structures of ethylene carbonate-based electrolyte solutions containing 1 mol/L LiPF6, LiN(SO2F)2 (LiFSI), or LiBF4 are experimentally determined, and their electron affinity and lowest unoccupied molecular orbital (LUMO) distribution are calculated by density functional theory (DFT). The stability of the electrolyte solutions against reduction can be evaluated using electron affinity of the solvates, and the formation mechanism of the solid electrolyte interphase (SEI) can be predicted by their LUMO distributions. The calculation results suggest that 1 mol/L LiPF6 and LiFSI electrolyte solutions should form SEI consisting of carbonate and carboxylate which derives from solvent decomposition and LiF originating from anion decomposition. These predictions are verified experimentally by scanning electron microscopy–energy dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy measurements. On the other hand, intriguingly, the reductive decomposition of 1 mol/L LiBF4 electrolyte solution does not simply proceed as theoretically predicted, and the subsequent reactions of SEI need to be considered: further decomposition of the organic SEI and formation of inorganic particles containing lithium, fluoride, oxygen, and boron. These results are consistent with an increase in the resistance of SEI and interfacial lithium ion transfer at the graphite negative electrode. Thus, a combination of DFT prediction and experimental analysis is an effective approach to reveal SEI formation mechanisms and can be utilized as a versatile approach to develop new solvents, electrolyte salts, and additives and to design electrolyte solutions with an appropriate concentration.

Behaviour of Radio- Thermoluminescence (X-Ray Irradiated), Thermal and Structural Characterization of Limestone

In this study, it was reported radioluminescence properties of limestone from Kütahya, Turkey for the first time in this study, which has been the subject of many studies in both mineralogical and gemological fields. Limestone is the general name of carbonate roks, which is the mineral with typical colors according to the impurity elements in rock and exhibited luminescence properties under x-ray irradiation. The radio&thermoluminescence data were analyzed for limestone. Besides, x-ray diffraction pattern was created for structural characterization, scanning electron microscope images and energy dispersive x-ray spectroscopy maps were taken to determine morphological features. When the radioluminescence spectrum of the limestone was detailed, a broad emission consisting of several peaks was observed in the visible region. In the thermoluminescence spectrum taken after the x-ray excitation of the limestone, three thermoluminescence peaks were observed at 97 oC, 170oC and 320 oC. Also; TL kinetic parameters are reported; The activation energy (E) and frequency factor (s) of the first peak were determined in detail using the methods of peak shape and varying heating rates.

Structural Correlation of Random Lasing Performance in Plasma-Induced Surface-Modified Gallium Nitride

The surface of GaN has been modified by a simple method that irradiates the substrate with Ar plasma and impurity codeposition, which is termed CoDE (Co-Deposition Etching). Unique structures were formed by the assistance of a small amount of Mo deposition without degradation of the crystal structure. The size of protrusions on the structure is influenced by the amount of deposited Mo particles. The mechanism for the structure formation is discussed based on transmission electron microscopy (TEM) observations and energy dispersive X-ray spectroscopy (EDS) measurements. Based on the GaN surface roughness, we have demonstrated random laser action in the UV region under photoexcitation. The lowest threshold (0.06 J/cm2) for random lasing was observed where the size of the structure is larger than 0.05 μm2, which was formed under conditions with the least amount of deposition. The correlation between the submicro/nanosize structures generated by plasma irradiation and lasing was evaluated in detail. The critical parameter to optimize the random lasing was determined to be the size of structures that can be modified by the Mo deposition rate. The results confirmed that the emission properties can be controlled by the processing conditions. This random laser fabrication technique is expected to be widely applicable to various direct-bandgap compound semiconductors.

Mechanical, Thermal Stability, and Flame Retarding Properties of Phosphorus-Modified PET Blended with DOPO-POSS.

In this study, an antidroplet flame retardant system based on FRPET (phosphorus-containing copolyester) is constructed with DOPO-POSS (polyhedral oligomeric silsesquioxane containing DOPO) as an additive flame retardant. It is demonstrated that DOPO-POSS has good dispersibility at a lower amount. When the amount of DOPO-POSS is 9 wt %, the residual char of DOPO-POSS/FRPET at 700 °C increases to 23.56 from 18.16% of FRPET, and the maximum thermal weight loss rate also reduces. What is more is that the limiting oxygen index increases to 33 from 26% of FRPET. The flame burning time is shortened to 4.95 from 20.8 s, the phenomenon of self-extinguishing of the fire occurs, and the vertical combustion level is increased from V-2 to V-0. Compared with FRPET, the peak of the heat release rate decreases by 66.0%, the total heat release decreases by 32.4%, the flame retardancy index (FRI) reaches an excellent value, and the condensed-phase products significantly improve. The Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy-energy dispersive X-ray spectrometry (SEM-EDX), thermogravimetric-FTIR (TG-FTIR), and pyrolysis-gas chromatograph/mass spectrometry (Py-GC/MS) results indicate that DOPO-POSS contributes to the formation of char layers and decomposes to generate free radicals with a quenching effect. In a word, DOPO-POSS is an effective radical trapper and charring agent for PET and exerts a flame retardancy effect in gaseous and condensed phases simultaneously.

Mn2O3 nanoparticle impregnated glycine max husks for the optimization of oil remediation in contaminated water

The sorption of crude oil using raw (unmodified) and Mn2O3 nanoparticle-modified glycine max husks was investigated for treatment of oil-spilled water surfaces by batch sorption technique. Box-Behnken design was employed for optimization of the sorption process by response surface methodology using design expert software. The sorbents’ characterization was by Fourier-transform infrared spectroscopy, scanning electron microscope–energy dispersive X-ray spectroscopy, Brunauer-Emmett-Teller surface area analysis, X-ray diffraction analysis, and Thermogravimetric analysis. Equilibrium isotherm data were evaluated using Langmuir, Freundlich, Temkin, and Scatchard models. The Langmuir gave the best fit to the experimental data and maximum monolayer uptake capacities of 3.47 and 5.29 gg−1 were obtained for the raw and nanoparticle-modified glycine max husks (RGMH and NGMH), respectively. Kinetics showed that their sorption will be satisfactorily described using pseudo-second-order, based on their large R2 values and at equilibrium uptake time of 70 and 50 min for oil onto the RGMH and NGMH, respectively. Thermodynamic parameters revealed a process that is non-spontaneous for RGMH, and spontaneous and feasible for NGMH. Regeneration and reusability after three sets of sorption-desorption were better with NGMH. Thus, Mn2O3 NGMH has greater potential as a sorbent for the management of oil-spilled water surfaces than RGMH.

Alleviation of Cr(VI) Toxicity and Improve Phytostabilization Potential of Vigna radiata Using a Novel Cr(VI) Reducing Multi-Stress-Tolerant Plant Growth Promoting Rhizobacterial Strain Bacillus flexus M2

Chromium (Cr) is a toxic heavy metal discharged into the environment through various anthropogenic sources, which affects soil properties and fertility. Hence, an effective soil restoration strategy is the need of the hour. In this study, a potent Cr(VI)-reducing strain M2 was isolated from the rhizosphere of Zea mays L. grown in leather industrial effluent contaminated sites and identified as Bacillus flexus through 16S rDNA sequencing. Strain M2 exhibited strong tolerance to multi-stresses such as temperature (up to 45 °C), pH (up to 9.0), Sodium chloride (NaCl) (up to 7%) and PEG 6000 (up to 50%) and showed strong Cr(VI) reduction with the presence of multi-stresses. The interaction of Cr(VI) with strain M2 was elucidated through various instrumentation analyses. Fourier Transform Infra-red (FTIR) Spectroscopy analysis confirmed that Cr(VI) exposures induce significant changes in the cell-surface functional groups. Raman spectrum and Transmission Electron Microscopy–Energy Dispersive X-ray spectroscopy (TEM-EDX) analysis confirmed the bio-reduction of Cr(VI) to Cr(III) and their intracellular localization as Cr(III). Further, strain M2 produced a significant quantity of Indole acetic acid (IAA), ammonia, and exopolysaccharide (EPS) and showed positive results for various plant-growth-promoting activities with the presence of Cr(VI). In greenhouse experiments, the strain M2 inoculation progressively increased the plant growth parameters and stabilized the antioxidant system of Vigna radiata under Cr stress. However, Cr(VI) exposure decreased the growth parameters and increased the level of proline content, Hydrogen peroxide (H2O2) accumulation, and antioxidant enzymes expression in V. radiata. Interestingly, strain M2 inoculation significantly reduced the accumulation of Cr in root and shoot of V. radiata when compared to the uninoculated Cr(VI) treatment. Hence, this study confirms that rhizobacterial inoculation markedly reduced the negative impact of Cr toxicity and improved V. radiata growth even in harsh environments by stabilizing the mobility of Cr in the rhizosphere.

Elemental Characterization of Leaded and Lead-Free Inorganic Primer Gunshot Residue Standards Using Single Particle Inductively Coupled Plasma Time-of-Flight Mass Spectrometry.

This study describes the use of single particle inductively coupled plasma time-of-flight mass spectrometry (spICP-TOFMS) for the detection and classification of inorganic gunshot residue (IGSR) particles. To establish reliable multi-element criteria to classify IGSR particles, leaded and lead-free IGSR reference materials were analyzed, and the elemental compositions of the individual particles were quantified. The results suggest that expanded element compositions may be used to classify IGSR particles via spICP-TOFMS compared to those used in conventional IGSR analysis using scanning electron microscopy energy dispersive X-ray spectroscopy (SEM-EDS). For spICP-TOFMS analysis of leaded IGSR particles, classification may be based on the presence of lead (Pb), antimony (Sb), and barium (Ba) just as in SEM-EDS; however, additional particle types, such as lead-copper (Pb-Cu) particles, contribute significantly (∼30%) to the leaded IGSR particle population. In lead-free IGSR particles, the dominate multi-metal particle composition found is titanium-zinc (Ti-Zn) with a conserved Zn:Ti ratio of 1.4:1, but other elements, such as copper (Cu), are also characteristic. In mixtures of the two IGSR reference materials, we were able to classify over 80% of the multi-metal particles detected with no false-positive particle-type assignments. With spICP-TOFMS, particles smaller than those typically measured by SEM-EDS are detected, with estimated median diameters for leaded and lead-free IGSR of 180 and 320 nm, respectively. Through measuring these smaller particles, up to ∼two times more particles per mL are recorded by spICP-TOFMS compared to that found by SEM-EDS. Overall, high-sensitivity and high-throughput analysis using spICP-TOFMS enables quantitative, rapid multi-elemental characterization, and classification of individual IGSR particles.

Optimization Effect of Metakaolin on Macro- and Micro-Mechanical Properties of Composite Cementitious Materials under Different Curing Conditions

To provide the theoretical basis for the engineering application of metakaolin as aluminum-rich pozzolanic ash materials, the promoting effect of metakaolin on the macro- and micro-mechanical properties of composite cement-based composite materials was explored under high-temperature steam and standard curing conditions. Analysis techniques, which involved thermogravimetric and nanoindentation coupled with scanning electron microscopy-energy dispersive X-ray spectroscopy, were used. To analyze the experimental data, the ACI empirical formula and the copula function were used. The correlation among the hydration degree of the MK-cement cementation system, the Al/Si of the C-(A)-S-H phase, and the nanomechanical properties of the C-(A)-S-H gel phase was investigated. According to prior research, the macroscopic mechanical properties and the substitution rate of the MK-cement composite cementitious system can be improved under high-temperature curing conditions in a short period, in which the optimum substitution rate of metakaolin is 20%. The ACI empirical formula was used to demonstrate the functional relationship between the metakaolin replacement rate, curing time, and compressive strength. The MK-cement cementation system can eliminate the defect phase, reduce the CH phase content, and then increase the C-(A)-S-H gel phase content and bulk density. The micro-mechanical properties of the C-(A)-S-H gel phase rises due to its phase content and Al/Si ratio. Furthermore, the copula function verifies the dependence of the nanomechanical properties of C-(A)-S-H gel and Al/Si.

Evaluation of the suitability of Pleurotus as a fluid loss control agent using the chemical structural properties approach

One of the main functions of the drilling fluid is to prevent filtrate from entering the formation by exhibiting good fluid loss properties during oil and gas drilling operations by sealing off the walls of the wellbore. Pleurotus is a type of edible mushroom that has been discovered by researchers to play the role of fluid loss additives in the mud system. The Pleurotus sample was processed as per the API standard and measured accordingly using laboratory measurements such as Scanning Electron Microscope Energy Dispersive X-ray Spectroscopy (SEM-EDS) for characterization, the X-Ray diffraction (XRD) methods used by scanning the sample to determine the chemical structure, name, and physicochemical properties by matching the results obtained with a different library, such as the NIST and PubChem. The Fourier Transform Infrared Spectrometer-FTIR 8600S helped to discover some of the functional groups which then confirmed the results and the matching of the XRD. The key chemical composition of Pleurotus are Chitin, glucans, and glycoproteins and their functional groups are amine (NH) and hydroxyl (R-OH), its high fiber and cellulose contents from chitin and glucans are the main constituents in the fluid loss control characteristics for its effectiveness. The position of the carbon-carbon, nitrogen-hydrogen, and hydrogen-oxygen indicating the point of the double bond was confirmed from the FTIR. The result of the sample was matched and found to be Psilocin which gave the structures to be more amorphous since they are more organic materials.