Traditional Preparation Methods Research Articles

In silico interactions and deep neural network modeling for toxicity profile of methyl methanesulfonate.

In this study, the toxicity induced by the alkylating agent methyl methanesulfonate (MMS) in Allium cepa L. was investigated. For this aim, bulbs were divided into 4 groups as control and application (100, 500 and 4000µM MMS) and germinated for 72h at 22-24°C. At the end of the germination period root tips were collected and made ready for analysis by applying traditional preparation methods. Germination, root elongation, weight, mitotic index (MI) values, micronucleus (MN) and chromosomal abnormality (CAs) numbers, malondialdehyde (MDA) levels, superoxide dismutase (SOD) and catalase (CAT) activities and anatomical structures of bulbs were used as indicators to determine toxicity. Moreover the extent of DNA fragmentation induced by MMS was determined by comet assay. To confirm the DNA fragmentation induced by MMS, the DNA-MMS interaction was examined with molecular docking. Correlation and principal component analyses (PCA) were performed to examine the relationship between all parameters and understand the underlying structure and relationships among these parameters. In the present study, a deep neural network (DNN) with two hidden layers implemented in Matlab has been developed for the comparison of the estimated data with the real data. The effect of MDA levels, SOD and CAT activities at 4 different endpoints resulting from administration of various concentrations of MMS, including MN, MI, CAs and DNA damage, was attempted to be estimated by DNN model. It is assumed that the predicted results are in close agreement with the actual data. The effectiveness of the model was evaluated using 4 different metrics, MAE, MAPE, RMSE and R2, which together show that the model performs commendably. As a result, the highest germination, root elongation, weight gain and MI were measured in the control group. MMS application caused a decrease in all physiological parameters and an increase in cytogenetic (except MI) and biochemical parameters. MMS application caused an increase in antioxidant enzyme levels (SOD and CAT) up to a concentration of 500µM and a decrease at 4000µM. MMS application induced different types of CAs and anatomical damages in root meristem cells. The results of the comet assay showed that the severity of DNA fragmentation increased with increasing MMS concentration. Molecular docking analysis showed a strong DNA-MMS interaction. The results of correlation and PCA revealed significant positive and negative interactions between the studied parameters and confirmed the interactions of these parameters with MMS. It has been shown that the DNN model developed in this study is a valuable resource for predicting genotoxicity due to oxidative stress and lipid peroxidation. In addition, this model has the potential to help evaluate the genotoxicity status of various chemical compounds. At the end of the study, it was concluded that MMS strongly supports a versatile toxicity in plant cells and the selected parameters are suitable indicators for determining this toxicity.

Cold plasma‐induced N, Cu‐doping on carbon paper for high‐active catalytic electrode preparation

AbstractCarbon paper is commonly used for catalytic electrode preparation because of its high conductivity, corrosion resistance, and stability. However, traditional electrode preparation methods are inappropriate for highly hydrophobic carbon paper. In this paper, a high‐activity carbon paper catalytic electrode was prepared using multistrategies cold plasma modification to create atomic structural defects, dope N and Cu elements, and introduce oxygen‐containing functional groups. Analyses show that the bombardment of high‐energy particles caused atomic structural defects. Nitrogen and copper entered the carbon paper through plasma‐induced chemical recombination and physical adsorption, reaching 5.26% and 3.83%, respectively. Ethanol‐based plasma introduced oxygen‐containing functional groups to improve hydrophilicity. Finally, the plasma‐prepared electrode exhibited a reduction efficiency of 87.69% in an electrocatalytic nitrate reduction reaction.

Antioxidative Potentials of Annona muricata Pulp and Allium cepa Bulb Juices

Aim: To establish the in vitro antioxidative potentials of juice samples of Annona muricata (soursop) fruit pulp and Allium cepa (onion) bulb. 
 Study Design: The experimental research design was adopted in this study, but without intervention. 
 Place and Duration of Study: Springboard Laboratories, Awka, Nigeria, in June 2022. 
 Methodology: Traditional method of juice preparation was used to prepare the juices of the soursop fruit pulp and onion bulb. The parameters assayed for were; ferric reducing antioxidant power (FRAP), nitric oxide, ABTS (2,2'-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid), superoxide, hydrogen peroxide (H2O2), DPPH (2,2-diphenyl-1-picrylhydrazyl), hydroxyl radical scavenging activities, total phenol content, total antioxidant capacity, and total flavonoids content using standard laboratory techniques at 100, 200 and 300 mg/ml concentrations of the samples in triplicates. Appropriate standards were set up alongside the tests to compare antioxidant properties of the test sample. 
 Results: The results showed that Annona muricata pulp and Allium cepa bulb juices, at the concentrations studied, possessed these antioxidant properties studied in varying quantities. It was also observed that values for total antioxidant capacity for soursop juice at 300 mg/ml concentration, and ABTS scavenging activity for onion juice at all concentrations were significantly higher than the reference. The value obtained for DPPH scavenging activity for onion juice at 300 mg/ml concentration and total flavonoids content for onion juice were statistically similar to the reference. 
 Conclusion: Both juices are natural sources of exogenous antioxidants which can be exploited to benefit humans.

The Comparative Efficacy of Conventional and Crown-Down Root Canal Preparation Techniques in Relation to the Extrusion of Apical Debris

Numerous scientific investigations have been undertaken to assess the efficacy of standard root canal preparation methods and the crown-down procedure in mitigating the ejection of apical debris. The aforementioned research examines multiple facets, encompassing the efficacy of canal cleaning, the potential for debris extrusion, and their influence on the outcome of root canal therapy. The objective of this study is to evaluate the efficacy of conventional and crown-down root canal preparation methods in relation to the extrusion of apical debris. The literature search used a lot of different databases, like PubMed, Web of Sciences, EMBASE, Cochrane Libraries, and Google Scholar, to look into how well traditional and crown-down root canal preparation methods work for getting debris out of the root canal. Traditional methods of root canal preparation have been extensively employed in the field of endodontics. While root canal cleaning and shaping techniques have demonstrated efficacy, there is still a potential danger of apical debris extrusion. Several factors contribute to the level of risk involved in dental procedures. These factors encompass the use of instruments, the amount of pressure applied during preparation, the effectiveness of irrigation, and the level of experience possessed by the dentist. In conclusion, the efficacy of both methodologies is contingent upon various aspects, including the level of expertise possessed by the dentist, the specific instruments employed, the irrigation technique employed, and the thoroughness of the case examination. The particulars of each case and the dentist's personal preference should guide the choice of either procedure.

Preparation and characterization of cellulose nanocrystals with high stability from okara by green solvent pretreatment assisted TEMPO oxidation

Because the traditional preparation methods of cellulose nanocrystals (CNCs) involve chemical pollution issues, in this study, two typical green solvents, alkali/urea solvent (AUS) and deep-eutectic solvent (DES), were used to dissolve insoluble soybean fibers (ISF) extracted from okara and prepare regenerated CNCs (AUS/CNC and DES/CNC), which were further modified by TEMPO oxidation (AUS/T-CNC and DES/T-CNC). The recoveries of AUS and DES were 82.58 % and 84.00 %, respectively. Chemical composition analysis showed high cellulose purity (>95 %) of the regenerated CNCs. FTIR, XRD and 13C NMR analysis indicated the cellulose structure and polymorph of CNCs. Thermal analysis revealed that the maximum degradation peak of regenerated CNC shifted to a lower temperature. AFM revealed that CNCs exhibited rod-like fiber structures, while AUS-pretreated CNCs exhibited some special spherical fibers. TEMPO oxidation showed an enhancement effect on the characteristics of AUS/T-CNC and DES/T-CNC; DES/T-CNC exhibited higher stability and apparent viscosity than AUS/T-CNC. The DES/T-CNC-based cryogel displayed a higher adsorption capacity for anthocyanin (0.40 g/g) and curcumin (1.09 g/g) with good controlled release capacity. These results indicated that green solvent pretreatment-assisted TEMPO oxidation is a new environmentally friendly and low-cost method for the preparation of CNCs and shows excellent potential in the field of drug loading and controlled release.

Synergistic reaction kinetics of Pt single atoms/MoS2 and nanoparticles for energy-saving hydrogen production assisted by green electrosynthesis of azotetrazolate compound

Overall water splitting (OWS) involves two important half-reactions, namely hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). However, due to the high theoretical overpotential of OER, OWS needs to be realized with high energy consumption. Using anodic oxidation reaction with lower theoretical potential to replace oxygen evolution reaction (OER) can effectively reduce the energy consumption of overall water splitting (OWS) for hydrogen production. Here, we introduce a new oxidation reaction of green electrosynthesis of energetic materials (EMs) and coupled with OWS. The catalyst was prepared by electrodepositing Pt nanoparticles (Pt NPs) and Pt single atoms (Pt SAs) on MoS2 nanosheets, which drives highly-efficient hydrogen production of 35.6 mV to drive 10 mA cm−2. DFT calculations reveal the synergistic mechanism of Pt NPs and Pt SA/MoS2 substrate for promoting hydrogen production, is that the energy barrier of water dissociation was reduced on the Pt NC sites and the produced H* migrated to the adjacent S sites for Heyrovsky step, while the Pt SA sites served as electron regulator for more thermoneutral H* adsorption on S sites, realizing the synergistic reaction kinetics in MoS2/Pt for promoting alkaline HER. Importantly, by integrating the OWS and electrosynthesis of 5,5′-azotetrazole (ZT) EMs, the cell voltage can be significantly reduced to 1.29 V at 10 mA cm−2, realizing low-energy-consumption for hydrogen production. Meanwhile, the green electrosynthesis of ZT is achieved to avoid the hazardous process of traditional preparation methods. This study presents a new strategy for green electrosynthesis of EMs and low-energy-consumption hydrogen production.

Mechanistic insights into the leaching and environmental safety of arsenic in ceramsite prepared from fly ash

Utilizing fly ash to prepare ceramsite is a promising way to immobilize heavy metals and recycle industrial solid waste. However, traditional preparation method of fly ash ceramsite has the disadvantages of large ignition loss. Therefore, the present study applied the pressure molding method to enhance solid content and improve the strength of ceramsite. The optimal preparation conditions of ceramsite were suggested as preheating at 450 °C for 25 min followed by sintering at 1050 °C for 30 min. Under such conditions, ceramsite with high compressive strength of 10.8 Mpa, bulk density of 878 kg m−3, and 1-h water absorption of 18.5% was fabricated, in compliance with Chinese standard (GB/T 1743.1–2010). The arsenic leaching concentration from the resulting product was considerably lower than Chinese standard (GB 5085.3–2007). Moreover, arsenic volatilization during ceramsite calcination was insignificant, and the vast majority of arsenic remained in resulting ceramsite. A geochemical speciation model developed for the multiple component system in ceramsite suggested that FeAsO4, Ca5(OH) (AsO4)3, and hydrous ferric oxide adsorption are the primary mechanisms retaining arsenic in ceramsite. Additionally, based on density functional theory calculations and biotoxicity test, the binding site of arsenic atom on mineral components and the environmental safety of ceramsite was determined and evaluated.

Polydimethylsiloxane membrane formed by thiol-ene photopolymerization for bio-alcohols pervaporation

Pervaporation (PV) membranes dominate the PV separation process. However, traditional preparation methods are usually low-efficient and time-consuming. Herein, we reported thiol-ene photopolymerization for fabricating PV membranes which had advantages in low shrinkage and low oxygen sensitivity compared with other photocuring systems. The membrane preparation could be completely finished within 10 s. In addition, the prepared PV membranes showed an excellent performance in separating bio-alcohols (methanol, ethanol, isopropanol and 2-butanol) and have a superior operation stability during 120 h. The thiol-ene method provides a universal strategy for fabricating PV separation membranes.

Enhancing bifunctional oxygen electrocatalysis with in-situ etching of oxide overlayers on sulfur-vacancy enriched CuCo2O4/CuCo2S4

Transition metal sulfide (TMS) are considered promising alternatives to noble metals for high-efficiency oxygen reduction and oxygen evolution (ORR/OER). However, traditional preparation methods or post-treatment processes can lead to the formation of oxide overlayers on the TMS catalysts, which can hinder their electrochemical performance. Herein, a sulfur-vacancy enriched CuCo2O4/CuCo2S4 heterostructure was prepared using cold plasma. Plasma also achieved the in-situ etching of oxide overlayers on the surface of catalysts. There is a strong correlation between the oxide overlayers and ORR/OER activity. Specifically, the number of ORR electrons transferred increased (n: from 2.8 to 3.7), while the OER overpotential decreased (η: from 417 to 330 mV) in 0.1 M KOH with the decrease of the oxide overlayer concentration (SO42−/SM−S: from 1.795 to 0.798). The theoretical calculation reveals the influence of oxide overlayers and S vacancy on the binding energy of the intermediate. The findings suggest that this work provides a new idea for designing metal sulfide electrochemical catalyst.

Research on the Preparation Process of SBS-Modified Asphalt Using Early Shearing Instead of High-Speed Shearing of Modifier

To investigate the effect of pre-shredding as a replacement for high-speed shearing in the preparation process of SBS-modified asphalt, the particle size and mixing time of pre-shredded SBS modifier were studied. Laser confocal microscopy was used to observe the morphological changes and dispersion state of the SBS modifier during the mixing process, and process parameters were determined through rheological performance tests. FTIR tests were conducted on the original asphalt and PAV-aged modified asphalt to assess the impact of the pre-shredding process on the chemical composition and aging resistance of the modified asphalt. The specific conclusions were as follows. During the preparation process of the SBS modifier using low-speed mixing, the morphological changes of the SBS modifier can be summarized as follows: It cycles through edge networking, mesh fiberization, and filamentous granulation, and eventually presents a granular atomization form after multiple cycles. It is recommended that the mixing time be maintained between 30 and 60 min, which results in the microstructure of the modified asphalt consisting of filamentous and point-like combinations. This asphalt exhibited excellent performance in high-temperature rut resistance, fatigue resistance, and low-temperature crack resistance. When the mixing time was too long, the SBS modifier formed small granules in an atomized state, which weakened the strength of the mesh structure and led to a decrease in overall performance. It is recommended that the SBS be shredded into particles sized between 18 and 30 mesh or 30 and 100 mesh. SBS-modified asphalt with SBS particles sized between 18 and 30 mesh exhibited greater hardness in the mesh structure, resulting in better high-temperature rut resistance. SBS-modified asphalt with SBS particles sized between 30 and 100 mesh had better extensibility in the mesh structure, leading to superior performance in medium-temperature fatigue resistance and low-temperature crack resistance. Compared to the conventional process, the pre-shredding process for preparing SBS-modified asphalt improved aging resistance by 10% to 13%. Additionally, SBS-modified asphalt prepared using the pre-shredding process saved 1 to 3 h of processing time compared to the traditional preparation method, reducing energy consumption. Furthermore, the asphalt produced through the new process exhibited better performance, reducing road wear and saving maintenance costs.

A Systemic Review on Comparative Study of Traditional And Modern Methods of Preparation of Ayurvedic Medicines

Affordable, high-quality Ayurvedic remedies may be the answer to today's healthcare demands of the Indian and worldwide communities. In order to scale up manufacturing of the medications, which is required to satisfy the rising demand, it is vital to relate Ayurvedic preparations with modern processing principles. For bettering the dosage forms, it's also crucial to comprehend the basic Ayurvedic concepts behind formulation and processing. There has been no systematic research to compare ancient and contemporary processing methods, despite the fact that the Ayurvedic sector has included technology from the food, chemical, and pharmaceutical industries. This study makes an effort to show a potential relationship between modern processing principles and Ayurvedic processing techniques. By gathering data from English translations of old Ayurvedic writings on medication preparation techniques, a thorough literature analysis was carried out to determine the Ayurvedic processing procedures. Based on the methods employed in Ayurvedic medication processing, a correlation between traditional and modern processing principles was conducted. Extraction and separation were found to be the two main types of procedures used in the manufacture of Ayurvedic medicines. Separation employs volatility, adsorption, and size-exclusion principles whereas extraction relies on membrane rupturing and solute diffusion principles. The study offers systematic recording of the Ayurvedic processes for making Ayurvedic medicines, coupled with an explanation of those processes in terms of modern processing principles. This is the initial stage that can lead to the advancement or replacement of conventional methods.

The system of preparing future teachers for providing moral education of schoolchildren within the digital learning environment: A comparative analysis of undergraduates and academics’ evaluative opinions

Introduction. The article is devoted to the problem of preparing future teachers for providing moral education of school students within the digital learning environment. The purpose of the study is to compare the attitudes of academics, who are developing the system of preparing future teachers for providing moral education of school students within the digital learning environment with students’ opinions about the effectiveness of its components. Materials and Methods. The research follows the systemic, activity-based and personality-oriented methodological approaches. The systemic approach allows to study the preparation of future teachers for providing moral education of schoolchildren in the digital learning environment as a system. The activity-based approach makes it possible to identify specific types of activities within the system. The personality-oriented approach contributes to selecting the contents according to the interests of future teachers. In order to achieve the purpose of the study, the authors used theoretical (analysis of scholarly literature, analysis of university work experience, generalization) and empirical (ranking, survey, interview) research methods. Statistical data processing was conducted by means of the Mann-Whitney U-test. The sample consisted of Education undergraduates (n = 122), newly-qualified teachers (the graduates of the university) (n =10), and academics (n=40). Results. The results of the theoretical research demonstrate that preparation of future teachers for providing moral education of school students within the digital learning environment has systemic characteristics and is implemented in the process of studying education disciplines, work placements, independent learning, participation in extra-curricular activities organized by the university, their own school experience, information obtained from the Internet, and studying experience of teaching staff at schools. The research supports the opinion that transferring skills between learning environments is a complicated task. Consequently, targeted work is required on order to prepare future teachers for educating school students in the digital learning environment. In the process of empirical research, it was revealed that the most effective ways of teacher training today are work placements, education disciplines, and personal learning experience of prospective teachers. The authors emphasized that students consider traditional methods of preparation, for example, independent learning, to be more effective than obtaining information from the Internet, while the academics have the opposite point of view. The results of the study have proven that the balance between the real and digital environments is significant for effective teacher preparation. Conclusions. The article concludes that the system of teacher education should be supplemented by the electronic learning environment which comprises theoretical and practical issues of providing moral education of school students within the digital learning environment. The preferences of future teachers and academics largely coincide, that can contribute to the effectiveness of education. However, academics overestimate the theoretical component of the curriculum.

Medicinal syrup for children from the association of significant parts of anti-COVID-19 medicinal plants from the Centre, Cameroon

Abstract. Lamy GML, Nnanga LS, Mahama, Ossongo AF, Elomo LB, Tagne RS, Mbo JA, Likeng JLN, Nga EN, Harmsen K. 2023. Medicinal syrup for children from the association of significant parts of anti-COVID-19 medicinal plants from the Centre, Cameroon. Asian J Nat Prod Biochem 21: 58-66. In Africa, Improved Traditional Medication (ITM) has been promoted since 1970 and classified into four categories. The import-substitution policy under the "Made in Cameroon" label encourages local production. Globally, there is an urgent need for anti-COVID-19 drugs, especially for children. The mechanisms of action of SARS-CoV-2 can be attenuated by combination therapy of the parts of anti-COVID-19 medicinal plants. A plant has several parts whose therapeutic properties generally differ. From 2020 to 2022, the most cited anti-COVID-19 plants in the literature were Allium sativum L., Citrus ×limon (L.) Burm.fil., Cymbopogon citratus (DC.) Stapf, and Zingiber officinale Roscoe. Unfortunately, a gap exists in the names of the significant parts of these plants. For example, were the barks, leaves, roots, or flowers used? In addition, the significant association of said plants and the majority of traditional preparation methods are not specified. The objective was to determine the significant parts of 4 anti-COVID plants, their significant association, and the majority traditional method of preparation allowing the pre-formulation of an infant anti-COVID ITM syrup. An ethnomedicinal survey, ANOVA, and the pre-formulation protocol of a medicated syrup were used. Altogether, 180 informants from several ethnic groups participated. The bulb and rhizome parts for A. sativum and Z. officinal showed a significant difference (P<0.05) between plants. The leaves and fruits of C. citratus and C. limon showed a highly significant difference (P<0.000) between plants. The association of four significant plants and infusion, the majority traditional mode of preparation, allowed the pre-formulation of the infant syrup named COVID-Med, an ITM category 2. The bulbs, rhizomes, leaves, and fruits were significant parts of A. sativum, Z. officinale, C. citratus, and C. limon.

КЛИНИЧЕСКАЯ ОЦЕНКА СОСТОЯНИЯ РЕСТАВРАЦИЙ В ОБЛАСТИ КЛИНОВИДНЫХ ДЕФЕКТОВ ПОСЛЕ ИСПОЛЬЗОВАНИЯ ХРОМ-ЭРБИЕВОГО ЛАЗЕРА WATERLASE IPLUS И ТРАДИЦИОННОГО МЕТОДА ПРЕПАРИРОВАНИЯ

Subject. Our study evaluated the effectiveness of two methods for the preparation of wedge-shaped defects of the teeth before performing aesthetic restorations: the traditional method of preparation and using Er,Cr:YSGG laser in three different modes. Evaluation of the effectiveness of these methods was carried out the next day after treatment, as well as after 6 and 12 months.
 Objectives. To evaluate the clinical condition of restorations using the Er,Cr:YSGG laser and the traditional preparation method.
 Methodology. In study i 80 patients were divided into 2 equal groups. The 1st group included patients with wedge-shaped teeth defects, who were prepared by the traditional method, the 2nd group included patients with wedge-shaped teeth defects, who were prepared with the Waterlase Iplus erbium laser (Biolase, USA). The second group was divided into 3 subgroups (13–14 people each), depending on the preparation mode used. All wedge-shaped defects were restored using Filtek Ultimate Flowable and Filtek Ultimate (3M ESPE, USA) composite material with preconditioning with 37% phosphoric acid and application of Adper Single Bond 2 adhesive (3M ESPE, USA).
 The condition of the restorations was assessed according to G. Ryge's clinically modified criteria on the next day after treatment, after 6 and 12 months.
 Results. Immediately after treatment and after 6 months, the condition of the restored teeth in both groups of traditional and laser preparations was not changed. The first changes in the state of the restorations appeared after 12 months. None of the restorations fell out during the entire treatment period.
 Conclusion. Restorations after the treatment of wedge-shaped defects with the Er,Cr:YSGG laser in accordance with G. Ryge's clinical modified criteria for 12 months do not change in 90% of cases and have ALPHA scores for all criteria; with the traditional method of preparation – in 87.5% of cases.

Influence of nitrogen sources on N-doped reduced TiO2 prepared using atmospheric plasma spraying for photocatalytic tetracycline and ciprofloxacin degradation

N-doped reduced TiO2 porous photocatalyst coatings are prepared by atmospheric plasma spraying (APS) technology combined with the geomimetic concept. Unlike traditional photocatalyst preparation methods, this method can be manufactured on a large scale and considerably shortens the preparation time by only 15 min. In this study, acetamide and urea, with one or two nitrogen atoms in the structure, were used as dopants to prepare N-doped TiO2 (T1N and T2N) for photocatalytic antibiotic degradation. Tetracycline (TC, 20 ppm/100 mL) and ciprofloxacin (CIP, 20 ppm/100 mL) were photodegraded under AM1.5G solar simulator illumination. The T1N obtained a higher lattice-nitrogen ratio than T2N, which gave T1N better photocatalytic activity. The rate constants of photodegradation of TC and CIP under simulated solar irradiation are 1.70 and 1.42 (×10−2 min−1), which are more than twice that of T2N and nearly 20 times higher than that of pristine TiO2. Moreover, after 10 rounds of recycling tests, the photocatalyst showed good performance and structural stability. The scavenger test suggested that ̇O2− is the most important reactive species in TC degradation, while ̇OH and h+ play an important role in CIP degradation. The degradation pathways of TC and CIP were proposed. This photocatalyst coating preparation method is suitable for large-scale production and is a time-saving, sustainable, diversified, and future-looking technology.

A New Method for Preparing Titanium Aluminium Alloy Powder

Due to TiAl alloys’ excellent properties, TiAl alloys have received widespread attention from researchers. However, the high energy consumption and lengthy process of traditional preparation methods have always limited the large-scale application of TiAl alloys. This article develops a new method for preparing TiAl-based alloy powder via the magnesium thermal reduction of TiO2 in AlCl3-KCl molten salt. In this study, the proportion of AlCl3&KCl molten salts was determined. We conducted phase analysis on the final product by studying the changes in temperature and time. It was found that the TiAl3 alloy powder could be obtained by being kept at 750 °C for 2 h, with an oxygen content of 3.91 wt%. The reaction process for the entire experiment was determined through thermodynamic calculations and experimental analysis, and the principles of the reduction process are discussed.

Ultrafast synthesis of 3D porous flash graphene and its adsorption properties

3D hierarchical porous graphene (3D HPG) has recently captured significant attention due to its unique porosities, excellent electron transport capability, and multifunctionality. However, given that the traditional preparation method of 3D HPG is time-consuming, energy-consuming and seriously polluting, which seriously block its wide application. This study leveraged the capabilities of flash Joule heating (FJH) to ultrafast synthesize 3D porous flash graphene (3D PFG) with good dispersion and adsorption properties from bituminous coal (BC) within 21 s. The thermal shock generated by carbonate pyrolysis and the thermal expansion generated by Joule heating were used to produce the stable porous structure. Moreover, the specific surface area of 3D PFG was as high as 504 m2g−1, and displayed the characteristics of hierarchical porous structure of micropores, mesopores and macropores. The porous structure changes of 3D PFG synthesized by FJH under different carbonate ratios and different flash voltages were investigated, and the controllable synthesis conditions of hierarchical pore structures during FJH were obtained accordingly. As the experimental and simulation results show, the 3D PFG displays good dispersibility and good adsorption performance as adsorbent for methylene blue and methyl orange. This environmentally friendly synthetic process of FJH not only simplifies the preparation process of 3D HPG but also provides a valuable way for the high value-added utilization of coal.

Mechanical crystallization induced Sm3+-doped CsPbBr3 quantum dots glass for high-sensitivity temperature sensing

The traditional preparation methods of quantum dots (QDs) for temperature sensing are limited to self-crystallization and secondary heat treatment processes, which requires precise control of the experimental equipment and conditions. In this paper, CsPbBr3 QDs are successfully obtained by friction crystallization in the prepared precursor glass. The results show that when the glass network structure is subjected to continuous mechanical impact, the thermal kinetic energy of the fracture surface increases. Therefore, the combination of relatively loose structure and local thermal energy supply more excellent space for the nucleation and growth of CsPbBr3 QDs. Furthermore, the PL enhancement is confirmed to be occur in Sm3+ ions doped CsPbBr3 QDs, which is due to the increase of density of exciton states near the edge of the band, thus facilitating radiative recombination. Significantly, this material has a favorable performance of temperature sensing and thermal stability, with the maximum relative sensitivity of 3.09 % K−1. This work provides an energy-saving and green way for the preparation of Sm3+ ions doped QDs, and the materials provide potential applications in the field of temperature sensing.

Molecular dynamics simulations guided the preparation of nano-silica/polyimide/cellulose composite insulating paper

Following the surge in power loads and continuous improvement in the voltage level, insulating papers' mechanical and electrical properties face new challenges. However, traditional inefficient “tentative” trial and error experiments are formidable to rapidly and efficiently prepare cellulose composite insulating paper because the direct scientific theory or simulation guidance is insufficient. To solve this problem, the nano-silica(nano-SiO2)/polyimide(PI)/cellulose composite models were designed and their mechanical, and dielectric properties were predicted by molecular dynamics (MD) simulation. The preparation of corresponding nano-SiO2/PI/cellulose insulating paper was guided by the MD simulation results and their surface morphology, mechanical properties, and electrical properties were investigated. The experimental results are in good agreement with the MD simulation results and confirmed that P3 insulating paper possesses the best comprehensive performance, and its tensile strength, relative permittivity, dielectric loss, volume resistivity, and breakdown strength are 71.44 MPa, 2.39, 0.2%, 5.16 × 1015 Ω∙m, and 75.8 kV∙mm−1, respectively. This work proves the feasibility and effectiveness of using MD simulation to guide the development of new insulating papers, and compared with the existing traditional preparation methods, this method is expected to be applied to study various new materials in the future and promote the vigorous development of new materials.

Preparation of Al-Ni Alloys of Different Phases Through Direct Electro-Deoxidation of Al2O3-NiO in CaCl2-NaCl Molten Salt

Al-Ni alloys have several common thermodynamically stable alloy phases. These alloys showed distinct physical properties and were applied in different fields, including aerospace and electrochemical catalysis. However, it is difficult to prepare Al-Ni alloys with the certain phase composition through traditional preparation methods, such as casting and mechanical alloying. Herein, Al-Ni alloys were prepared through electro-deoxidation in CaCl2-NaCl molten salt. Pure Al-Ni alloys phases (AlNi3, AlNi and Al3Ni2) were obtained after optimizing the electro-deoxidation conditions, such as the molar ratio of Al and Ni in the original tablet, the sintering temperature of the precursor, electro-deoxidation time and the molten salt temperature. The deoxidation processes of the Al2O3-NiO composite were investigated through various electrochemical methods, such as cyclic voltammetry, chronoamperometric curve and constant potential electro-deoxidation experiment. The loss of Al2O3 in the molten salt was confirmed to be responsible for the loss of Al in the electro-deoxidation processes. Meanwhile, it was proposed that the loss of Al could be efficiently delayed by increasing the precursor’s sintering temperature and the molten salt temperature. The obtained Al-Ni alloys (AlNi3, AlNi and Al3Ni2) could be used as efficient additives in the cathode of lithium–sulfur batteries to improve the charging/discharging capacity.