TG-DSC Analysis Research Articles

Li/Na/K carbonate solar salts for enhanced and integrated carbon capture and utilization via reverse water gas shift (ICCU-RWGS)

This study introduces a novel ICCU-RWGS process using Li, Na, and K carbonates mixed with boric acid as dual functional materials, enhancing CO2 capture and conversion without traditional CaO adsorbents. These molten salts, compatible with solar energy systems, enable efficient integration with CSP, storing heat from CO2 capture for utilization. The addition of boric acid significantly boosts CO2 uptake and conversion, achieving 2.0 mmol, 1.1 mmol, and 1.3 mmol CO2 uptake with conversion of 51.1 %, 58.3 %, and 57.6 % over three cycles, respectively. A 10-cycle test confirmed stable performance, with conversion rates between 53.0 % and 58.7 %. Characterization techniques (XRD, SEM, TEM, XPS, in-situ DRIFTS) revealed new borate phases after CO2 capture. TG-DSC analysis showed exothermic peaks during CO2 capture and RWGS stages, indicating that molten salt has the potential to generate heat for CSP systems, thus offering efficient CO2 conversion and sustainable energy recovery.

Comparative Analysis of Dielectric Behavior under Temperature and UV Radiation Exposure of Insulating Paints for Electrical Equipment Protection—The Necessity of a New Standard?

This paper describes the behavior of some epoxy, acrylic and polyurethane paints used in the protection of electrical equipment under the action of different degradation factors. The degradation factors chosen were temperature and UV radiation. The behavior of the paints under the action of these factors was interpreted by the variation of the tangent of the dielectric loss angle (tg Delta) as well as by FTIR and TG DSC analyses. Tg Delta was considered the reference dielectric characteristic because it best simulates the functionality of the material. The results presented in this paper lead to the conclusion that exposure to thermal cycles and UV radiation is necessary for each paint to give indications about their possibility of use in these conditions. At the same time, the evaluation of thermal stability, even if the exposure is at lower temperatures (than those at which we performed the tests) and/or for shorter periods, is very important for placing the paint in an insulation class. The tests that were the subject of this work provide us with the following information about the three types of paints analyzed: the highest resistance to thermal cycles is presented by S3, followed by S2 and then S1; thermal endurance tests place the polyurethane paint (S3) in insulation class E and the epoxy paint (S1) in insulation class B; and the tests to determine resistance to UV radiation qualify the best paint as acrylic (S2) and the worst as polyurethane (S3). Thus, it can be said that in applications where it is necessary for the protective film to withstand high temperatures, the use of S3 paint (polyurethane) is recommended, and in applications where the films are kept under the influence of UV radiation for a longer time, it is recommended to use coded paint S2 (acrylic). The results presented in this paper lead to the conclusion that the exposure to thermal cycles simulating the use in outdoor conditions and the resilience of paints under UV radiation conditions must be performed for each paint according to its specific use, and the dielectric characteristics must be carefully evaluated because they can reach values under the accepted limit—e.g., thermal stability evaluation—even if the exposure is at lower temperatures and/or for shorter periods. The conclusions of the experimental work must be generalized at different types of electrical insulating paints, and maybe a new standard is necessary to assess the paints’ behavior under usage conditions, with the paints needing to be treated separately from the classical polymeric insulation systems.

Thermal behavior of the dielectric response of composites based on poly(vinylidene fluoride) filled with two-dimensional V2CTx MXenes.

In this study, two-dimensional V2CTx MXenes were prepared by an accessible and rapid method, which involved aluminothermic combustion synthesis of the V2AlC MAX phase and its further processing in an HCl/LiF mixture under hydrothermal conditions. The resulting V2CTx MXene was characterised by XRD, SEM, TEM and XANES. A colloidal solution of the V2CTx MXene in dimethylformamide was used to prepare nanocomposites based on a poly(vinylidene fluoride) polymer matrix with a conductive filler content of 2.5 to 20 wt%. The nanocomposites were characterised by XRD, SEM and simultaneous DSC-TG analysis. The dielectric properties of the nanocomposites were studied using impedance spectroscopy in the frequency range from 100 Hz to 1 MHz at temperatures from -50 to +140 °C. The results showed that adding 20 wt% V2CTx to PVDF allows increasing the permittivity to 425.3 with a dielectric loss tangent of 0.54 at a frequency of 10 kHz. Studies of the temperature behavior of the dielectric response of composites have shown that the nature of the temperature dependence of the permittivity and dielectric loss tangent was determined mainly by the characteristics of the PVDF polymer matrix, while the filler had a significant effect only on the interfacial polarization, which increased with increasing V2CTx filler concentration and temperature.

Preparation of lightweight porous slag-based geopolymer highly hydrophobic materials for efficient oil-water separation

Surface hydrophobic modification is a critical technology for enhancing the application properties of materials, crucial for the development of geopolymer materials in oil-water separation. in this study, a lightweight porous slag-based geopolymer highly hydrophobic materials (PSGHHMs) were successfully prepared in-situ using slag and liquid water glass by varying different influencing factors, such as the amount of water/foaming agent/polymethylhydrosiloxane (PMHS) and the curing temperature. The PSGHHMs exhibited high strength, large flux and excellent highly hydrophobic properties, with contact angle reaching 156.14° and a sliding angle of less than 2°. SEM-EDS, TG-DSC and FT-IR analysis reveal that the in-situ modification mechanism of PSGHHMs involves the hydrolysis of Si-H in PMHS under alkaline conditions to form Si-OH. This subsequently reacts with Ca-OH in C-S-H gel to produce Ca-O-Si. Consequently, the PSGHHMs retained their excellent highly hydrophobicity even after calcination at 450℃ for 2.5 h. The PSGHHMs demonstrated robust resistance to acid/alkali/salt corrosion, as well as to friction, with the ability to quickly restore damaged highly hydrophobic properties. Additionally, the PSGHHMs could quickly absorb light/heavy oils, and achieving a desorption efficiency of over 99 %. They were also capable of continuously separation of oil-in-water emulsions and oil-water mixtures. Given these properties, the PSGHHMs have broad potential applications in antifreezing, antifogging, drag reduction and oil-water separation.

Study on the Preparation and Compressive Strength of Boron Mud-Based Basic Magnesium Sulfate Cement.

The direct discharge of boron mud poses significant environmental hazards to soil and groundwater. Despite extensive research efforts, the reprocessing of boron mud has not yielded significant advancements. Recently, the development of magnesium cement has spurred interest in the reutilization of boron mud. However, the direct treatment of boron mud remains challenging, necessitating pre-treatment in most studies to achieve substantial results. Consequently, research on the direct incorporation of untreated boron mud is scarce. This study explores the feasibility of using uncalcined boron mud as a base material in basic magnesium sulfate cement (BMSC), composed of lightly calcined magnesia and magnesium sulfate heptahydrate. The effects of varying boron mud content on the compressive strength of the BMSC system were investigated. The results indicate that the 5·1·7 phase is the primary strength phase of BMSC. When the boron mud content is 30%, the uncalcined boron mud has a minimal impact on the formation of the 5·1·7 phase. Additionally, the 28 days compressive strength of BMSC-B30 showed a slight difference compared to the control group BMSC-C, registering at 66.7 MPa. TG-DSC analysis revealed that the presence of a small amount of boron mud inhibits the micro-expansion trend of the BMSC structure. Furthermore, XRD and SEM analyses confirmed that the addition of uncalcined boron mud does not significantly alter the phase structure of the 5·1·7 phase in BMSC. This study provides a foundational basis for the long-term development of direct boron mud treatment.

Sorption Drying of Wheat Seeds Using Kieserite as a Solid Desiccant

The moisture content (MC) of wheat seeds must be reduced before storage using appropriate dehydration processes. Desiccant drying is a promising alternative to conventional drying methods because it improves seed quality while providing overall energy efficiency. This study explores the sorption drying of wheat seeds using granulated kieserite MgSO4·H2O as a solid desiccant, which has a high water capacity and is regenerated at low temperatures <100 °C. Desiccant characterization was conducted using SEM-EDS, XRD, DSC-TG, and particle size analysis. Wheat seeds mixed directly with kieserite in various mass ratios were dried under uniform stirring and controlled temperature conditions. A 240-min drying time was required to reduce the initial MC of wheat from 21.5% to 15.1% at a desiccant-to-grain ratio of 1:1. After 360 min, a final MC of 14.4% was achieved. The germination energy and seed capacity after sorption drying were 91 ± 1% and 97 ± 2%, respectively. Due to the available water capacity of kieserite, several batches of seeds can be dried without intermediate desiccant regeneration. This study is useful for developing low-cost, non-thermal, and sustainable drying technology for various agricultural products.

From hydratable alumina bonded high chrome castables to shaped product for coal water slurry gasifier

The gasifier is a key equipment of coal gasification technology, enabling efficient and clean utilization of coal resources. However, the aluminum phosphate bonded high chrome brick lining in the gasifier experienced premature failure due to the migration of phosphate in reducing gases such as H2 and CO, as well as increased slag penetration and thermal spalling. In this study, a high chrome castable was prepared using hydratable alumina as a binder and fired at 1600 ℃ to replace the traditional phosphate bonded high chrome brick. The impact of curing temperatures (25℃, 40 ℃, and 60 ℃) on the properties of the high chrome castable was investigated, with corresponding hydrates examined through XRD, FTIR, TG-DSC, and SEM analyses. Results revealed that higher curing temperatures accelerated the hydration process of hydratable alumina. At higher curing temperatures, more well-developed micro-nano sized boehmite and bayerite phases were formed within the castables, filling their pores effectively and enhancing their properties after drying at 110 ℃. Moreover, during heat treatment these micro-nano sized hydrates decomposed into submicron/nano sized alumina which readily reacted with Cr2O3 to form (Cr-Al)2O3 solid solution. This phenomenon facilitated the sintering of castables fired at 1600 ℃ and optimized internal structure, ultimately leading to the enhanced mechanical properties and improved slag resistance.

Synthesis and characterization of energy-efficient Mq2 (M=Zn, and Pb) organometallic complexes for OLED display applications: Illuminating the future of visual technology

In recent years, display technology has made significant advancements, with Organic Light Emitting Diode (OLED) displays standing out as one of the most groundbreaking developments. OLEDs have fundamentally transformed the landscape of visual technology by offering vibrant, energy-efficient, and flexible displays utilized in a wide array of products, from smartphones to large-scale television screens. This study focused on nanoparticles of bis-(2-methyl-8-hydroxyquinoline) zinc (Znq2) and bis-(2-methyl-8-hydroxyquinoline) lead (Pbq2). A straightforward chemical precipitation process was employed for their synthesis. Organometallic complexes, a class of substances that significantly enhance the efficiency, color purity, and durability of these advanced displays, play a crucial role in the outstanding performance of OLEDs. The nanoparticles' crystalline nature was characterized using powder X-ray diffraction (PXRD). Morphology and elemental content were examined using energy dispersive X-ray analysis (EDAX). Fourier transform infrared (FTIR) spectroscopy was employed to investigate the compound's functional groups. Thermal stability was assessed through TG-DSC analysis of the particles. Optical characteristics were studied using UV–visible spectroscopy. The potential luminescence property of the synthesized particles was confirmed through examination of the photoluminescence spectrum.

The Synthesis, Structural Characterization, and DFT Calculation of a New Binuclear Gd(III) Complex with 4-Aacetylphenoxyacetic Acid and 1,10-Phenanthroline Ligands and Its Roles in Catalytic Activity.

A new binuclear Gd(III) complex, [Gd2(L)6(Phen)2]·4H2O, was synthesized via the reaction of gadolinium(III) nitrate hexahydrate, 4-acetylphenoxyacetic acid (HL), NaOH, and 1,10-phenanthroline (Phen) in a solution of water-ethanol (v:v = 1:1). The Gd(III) complex was characterized using IR, UV-vis, TG-DSC, fluorescence, and single-crystal X-ray diffraction analyses. The results showed that the Gd(III) complex crystallizes in the triclinic system, space group P-1, and each Gd(III) ion was coordinated with two nitrogen atoms (N1, N2, or N1a, and N2a) from two Phen ligands and seven oxygen atoms (O1, O2, O7a, O9, O8, O8a, O10a, or O1a, O2a, O7, O8, O8a, O9a, and O10) from six L ligands, respectively, forming a nine-coordinated coordination mode. The Gd(III) complex molecules formed a one-dimensional chained and three-dimensional network structure via benzenering π-π stacking. The Hirschfeld surface analysis and the calculations of the electron density distributions of the frontier molecular orbitals of the Gd(III) complex were performed. The catalytic activities of the photocatalytic CO2 reduction and benzyl alcohol oxidation using the Gd(III) complex as a catalyst were performed. The results of the photocatalytic CO2 reduction showed that the yield and the selectivity of CO reached 41.5 μmol/g and more than 99% after four hours, respectively. The results of the benzyl alcohol oxidation showed that the yield of benzaldehyde was 45.7% at 120 °C with THF as the solvent under 0.5 MPa O2 within 2 h.

Structural Evolution of Mn-Substituted FeOOH and Its Adsorption Mechanism for U(VI): Effect of the Mole Ratio of Mn/(Fe + Mn)

Mn-substituted FeOOH with different Mn/(Mn + Fe) molar ratios are synthesized, and characterized using FESEM, XRD, FTIR, ICP-OES, BET, Zeta potential, TG-DSC, XPS, and VSM. The results show that the actual doping amounts of Mn are 0%, 3.05%, 6.13%, 9.04%, 12.70%, and 15.14%, respectively. The substitution of Mn promotes the transformation of goethite from FeOOH to MnFe2O4, resulting in a saturation magnetization intensity of up to 14.90 emu/g for G-Mn15%, laying a theoretical foundation for magnetic recovery. The specific surface area of Mn-substituted FeOOH increases from 57.15 m2/g to 315.26 m2/g with an increasing Mn substitution amount. Combined with the abundant oxygen-containing functional groups such as -OH, Fe-O, and Mn-O on the surface, sufficient active sites are provided for the efficient adsorption of U(VI). The TG-DSC analysis results indicate that the substitution of Mn improves the thermal stability of goethite. In addition, XPS analysis results indicate that the substitution of Mn leads to the conversion of Fe3+ to Fe2+ in goethite, and the conversion of Mn2+ to Mn3+ replaces Fe3+ in the structure of goethite. Fe-O and Mn-O coordinate participate in the adsorption and reduction process of U(VI). The batch experiment results show that the substitution of Mn promotes the adsorption performance of goethite for U(VI). When T = 303 K, pH = 4.0, m/V = 0.5 g/L, and I = 0.01 mol/L NaCl, the maximum adsorption capacity of G-Mn15% for U(VI) is 79.24 mg/g, indicating the potential value of Mn substitution for goethite in the treatment of uranium-containing wastewater.

Impact of Lime Saturation Factor on Alite-Ye'Elimite Cement Synthesis and Hydration.

Alite(C3S)-Ye'elimite(C4A3$) cement is a high cementitious material that incorporates a precise proportion of ye'elimite into the ordinary Portland cement. The synthesis and hydration behavior of Alite-Ye'elimite clinker with different lime saturation factors were investigated. The clinkers were synthesized using a secondary thermal treatment process, and their compositions were characterized. The hydrated pastes were analyzed for their hydration products, pore structure, mechanical strength, and microstructure. The clinkers and hydration products were characterized using XRD, TG-DSC, SEM, and MIP analysis. The results showed that the Alite-Ye'elimite cement clinker with a lime saturation factor (KH) of 0.93, prepared through secondary heat treatment, contained 64.88% C3S and 2.06% C4A3$. At this composition, the Alite-Ye'elimite cement clinker demonstrated the highest 28-day strength. The addition of SO3 to the clinkers decreased the content of tricalcium aluminate (C3A) and the ratio of Alite/Belite (C3S/C2S), resulting in a preference for belite formation. The pore structure of the hydrated pastes was also investigated, revealing a distribution of pore sizes ranging from 0.01 to 10 μm, with two peaks on each differential distribution curve corresponding to micron and sub-micron pores. The pore volume decreased from 0.22 ± 0.03 to 0.15 ± 0.18 cm3 g-1, and the main peak of pore distribution shifted towards smaller sizes with increasing hydration time.

Solid-liquid equilibrium of in some pure solvents and binary solvents from 293.15 K to 318.15 K

The solubility of nicotinohydrazide in two binary solvents were determined by a static weight method from 293.15 to 318.15 K. It found that the solubility of nicotinohydrazide was influenced by temperature, solvent polarity, and solvent composition. Meanwhile, the TG-DSC analysis was used to obtain the weight change and thermal effect of nicotinohydrazide. The XRD analysis indicated that the crystal morphology of nicotinohydrazide was coincident in five different solvents. Furthermore, the models including modified Apelblat equation, Van’t Hoff equation, Jouyban-Acree model, and CNIBS/R-K model were used to fit the experimental data. It was concluded that the four models were reliable in fitting the experimental data. Then the dissolution apparent thermodynamic was obtained, which explained well the dissolution of nicotinohydrazide. This study could help optimize and control the industrial crystallization of nicotinohydrazide.

Industrial Two-Phase Olive Pomace Slurry-Derived Hydrochar Fuel for Energy Applications.

The present study aims to resolve the existing research gaps on olive pomace (OP) hydrochars application as a fuel by evaluating its molecular structures (FTIR and solid NMR analysis), identifying influential characteristics (Pearson correlation analysis), process optimization (response surface methodology), slagging-fouling risks (empirical indices), and combustion performance (TG-DSC analysis). The response surfaces plot for hydrothermal carbonization (HTC) of OP slurry performed in a pressure reactor under varied temperatures (180-250 °C) and residence times (2-30 min) revealed 250 °C for 30 min to be optimal conditions for producing hydrochar fuel with a higher heating value (32.20 MJ·Kg-1) and energy densification ratio (1.40). However, in terms of process efficiency and cost-effectiveness, the optimal HTC conditions for producing the hydrochar with the highest energy yield of 87.9% were 202.7 °C and 2.0 min. The molecular structure of hydrochar was mainly comprised of aromatic rings with methyl groups, alpha-C atoms of esters, and ether bond linkages of lignin fractions. The slagging and fouling risks of hydrochars were comparatively lower than those of raw OP, as indicated by low slagging and fouling indices. The Pearson correlation analysis emphasized that the enrichment of acid-insoluble lignin and extractive contents, carbon densification, and reduced ash content were the main pivotal factors for hydrochar to exhibit better biofuel characteristics for energy applications.

Efficient Extraction of Lithium from Calcined Kaolin Lithium Clay with Dilute Sulfuric Acid

In this study, the structure and phase transition of kaolin lithium clay at different calcination temperatures were studied and discussed; subsequently, the effects of Li leaching with sulfuric acid under various factors were investigated in detail. The experimental results indicated that an optimal Li leaching rate of 81.1% could be achieved when kaolin lithium clay was calcined at 600 °C for 1 h, followed by leaching with 15.0% sulfuric acid at 80 °C for 2 h. The TG-DSC, XRD, and SEM analyses showed that the layered structure of the clay was not destroyed during the leaching and calcination processes. During the process of calcination, kaolinite was converted to metakaolinite via dehydroxylation. During the process of leaching, the Al on the surface of the metakaolinite was dissolved by sulfuric acid, resulting in the destruction of the Al-O structure; then, Li+ was exchanged for H+ to the surface of the mineral and entered the solution under the action of diffusion. The leaching kinetics showed that the leaching process was controlled by a diffusion model, and the activation energy (Ea) was 41.3 kJ/mol. The rapid extraction of Li from calcined kaolin lithium clay with sulfuric acid leaching offers a high-efficiency, low-energy-consumption strategy for the utilization of new lithium resources.

In-situ synthesis of MEMS compatible Al/Cu2HIO6/PVDF Metastable composites film with high combustion performance

To address the challenges related to significant pressure loss and weakened combustion performance of energetic materials when ignited on Micro-Electro-Mechanical Systems (MEMS), periodate-based MICs (Metastable Intermolecular Composites) have emerged as promising candidates due to their high energy density and combustion pressure. However, the integration of periodate-based MICs onto MEMS has not been effectively achieved thus far. Herein, we propose a simple, environmentally friendly, and cost-effective approach to fabricate a MEMS-compatible Al/Cu2HIO6/PVDF (polyvinylidene difluoride) energetic composite film. Our method involves utilizing a Cu(OH)2 array as a template and employing an in-situ and spin-coating process. The resulting Al/Cu2HIO6/PVDF film was characterized using various techniques including SEM, TEM, XRD, and XPS. These analyses reveal a tightly packed nano array morphology with a porous structure. DSC-TG analysis was conducted to investigate the thermal reaction of the Al/Cu2HIO6/PVDF composite film. The results demonstrate that the thermal reaction involved a complex multi-step process, with higher heat release (1121 J g-1), a faster reaction rate, and a lower initial reaction temperature (294.5 °C) compared to the Al/CuO/PVDF composite film. the reaction process of Al/Cu2HIO6/PVDF film was also been proposed by analyzing the products at different temperatures. combustion diagnostic tests were carried out to evaluate the combustion performance of the Al/Cu2HIO6/PVDF composite film. The results indicate that as CuO transformed into Cu2HIO6, the film exhibits a reduced ignition delay (8 ms) and combustion duration (50 ms), higher combustion temperature (3710 K), and stronger flame intensity (8630 a.u.).

FeS-assisted restructuring of zinc-bearing phases into sulfated compounds for efficient zinc extraction from hazardous electric furnace dust

Electric arc furnace dust (EAFD) is a hazardous solid waste generated as a byproduct in the steelmaking process, containing significant amounts of zinc and iron, making it a primary secondary source of zinc. The separation of zinc and iron in an environmentally-friendly and efficient manner poses a crucial technological challenge for the safe disposal and resource utilization of EAFD, facilitating the recovery of valuable zinc and the direct reuse of iron as raw materials for ironmaking. In this study, a novel method for restructuring zinc-bearing phases into sulfated compounds through low-temperature roasting by introducing FeS in EAFD were proposed. Simultaneously, the iron-containing phases undergo a transformation into Fe2O3. Subsequently, efficient separation of zinc and iron is achieved through a leaching process using dilute sulfuric acid. The conditions for the theoretical transformation of zinc-containing phases into ZnSO4 and iron-containing phases into Fe2O3 in EAFD were determined by thermodynamic calculations incorporating FeS. The temperature range for sulfation calcination was determined to be within 550–700 °C based on TG-DSC analysis and the evaluation of SO2 release during the decomposition of FeS. The optimal conditions for the roasting process were determined as an E/F ratio of 1:3, a temperature of 650 °C, and a duration of 3 h. In addition, the optimal conditions for the leaching process were determined as the addition of 1 mL of 1 M H2SO4 and a liquid–solid ratio of 25 mL/g. Under these conditions, the extractions of Zn and Fe reached 95.33 % and 0.17 %, respectively. The mechanism of phase reconstruction from zinc-containing phases to sulfate phases in EAFD was thoroughly analyzed, revealing that the Zn species in EAFD were transformed into Zn3O(SO4)2 through solid–solid and gas–solid reactions, while the majority of Fe species in EAFD and FeS were converted into Fe2O3. Effective separation of zinc and iron was achieved by dissolving Zn3O(SO4)2 in diluted sulfuric acid while retaining Fe2O3 in the residue. This study provides a fresh perspective on the recovery of zinc from zinc-containing solid waste resources, offering significant potential for the sustainable management and utilization of EAFD.

Radiation-chemical synthesis and characterization of ferrihydrite from iron (III) nitrate

In this study, 2-line ferrihydrite (2L Fh) nanoparticles (NPles)were synthesized by radiation-chemical method from an alcoholic solution of iron (III) nitrate for the first time. The X-ray diffraction analysis confirmed that the synthetic powder exhibited the characteristic pattern of 2L Fh NPles. DSC-TG analysis conducted in air atmosphere further verified the formation of 2L Fh. SEM analysis showed the presence of mesoporous plate-like structures in the 2L Fh powder, consisting of aggregates of NPs with an average size of approximately 20 nm. The absence of impurity peaks on the X-ray diffractograms and energy dispersion spectra (EDX) confirmed the chemical purity of the produced 2L Fh NPles. Additionally, the XPS method detected the presence of nitrogen and carbon adsorbed to the developed surface of the 2L Fh plates. 2L Fh NPles, when dried in air at a temperature of 50 °C, rapidly dissolved in water. 2L Fh NPles alcohol suspensions were stabilized using surfactants polyethylenimine (PEI) and acetylacetone (AcAs). 2L Fh NPles showed good photocatalytic properties when irradiated with ultraviolet light of methyl violet (MV) dye. These 2L Fh NPles, synthesized using an environmentally friendly radiation-chemical method, have immense potential for applications in biomedicine and photocatalysis.

Application of microencapsulated fibrous carrier inhibitors in suppressing flake aluminum dust explosion: Performance and mechanism

Flake aluminum powder (FAl), due to its larger specific surface area and higher reactivity, posing a potential threat to the process safety of involved enterprises. To mitigate the explosion caused during the production of FAl, a green composite inhibitor, Sep@CS@PA-Na, was successfully prepared in the aqueous phase using microencapsulation technology with sepiolite (Sep), chitosan (CS), and sodium phytate (PA-Na) as raw materials. The suppression of FAl explosions in a vertical combustion duct system by inhibitors with different inerting ratios (α) was investigated. The results showed that after adding Sep@CS@PA-Na with an α of 0.75, the maximum flame propagation velocity (Vmax), the average flame velocity (Vavg), and the velocity of the flame reaching the pipeline top (Vtop) decreased by 79.6%, 75.1%, and 86.2%, respectively, and the reduction of the maximum flame front pressure (Pmax) and the maximum flame pressure rise rate ((dP/dt)max) were 90.4% and 89.8%, respectively, and the peak temperature (Tp) dropped to 505°C. Combined with TG-DSC and explosion product analysis, Sep@CS@PA-Na possessed both gas-phase reaction and surface reaction suppression functions, which were mainly reflected in the dilution effect, quenching effect, and barrier effect. This work will provide technical support for the emergency prevention and control of energetic metal dust explosions.

Synthesis of new-type, cost-effective and insensitive energetic materials via nitration of solid bituminous hydrocarbons.

A global trend for the development of energetic materials using various sources is promoted by researchers annually. Solid bituminous hydrocarbons can play a key role in carbon science as abundant, low-cost, and mineral carbonaceous substrates. This study focuses on the design and synthesis of a series of new energetic materials from natural asphalt (NA), petroleum pitch (PP) and petroleum bitumen (PB) as industrial and available solid bituminous hydrocarbons. Energetic materials NA-NO2, PP-NO2 and PB-NO2 were synthesized through the nitrification reaction. The heat of combustion, thermal behaviors and FTIR, elemental, BET, UV-vis, SEM, EDX-map, AFM, GC-MS and TG-DSC analyses were applied to identify and confirm that all were prepared successfully. Further, the physicochemical and energy properties of NA-NO2, PP-NO2 and PB-NO2 were calculated using EMDB V 1.0 software. Thermal analysis showed thermal stability and insensitivity of NA-NO2, PP-NO2 and PB-NO2 toward mechanical stimuli. The combustion heats of NA-NO2, PP-NO2 and PB-NO2 were measured using a calorimeter bomb via the ASTM D240 method and evolved high amounts of energy of 23 500, 23 450 and 23 360 kJ kg-1, respectively. The density of NA-NO2 was measured using the ASTM-D8176 test and confirmed to be 0.5 g cm-3, which can be considered the lightest energetic material. Based on the conducted studies and analyses, new energetic materials synthesized based on solid bituminous hydrocarbons are classified as first-generation energetic materials.

Structure and performance regulation of energetic complexes through multifunctional molecular self-assembly.

The design of novel energetic compounds constitutes a pivotal research direction within the field of energetic materials. However, exploring the intricate relationship between their molecular structure and properties, in order to uncover their potential applications, remains a challenging endeavor. Therefore, employing multi-molecule assembly techniques to modulate the structure and performance of energetic materials holds immense significance. This approach enables the creation of a new generation of energetic materials, fueling research and development efforts in this field. In this study, a series of coordination compounds are synthesized by utilizing tetranitroethide (TNE) as an anion, which possesses a high nitrogen and oxygen content. The synthesis involves the synergistic modification between metal ions and small molecule ligands. Characterization of the obtained compounds is carried out using various techniques, including single crystal X-ray diffraction, IR spectroscopy, elemental analysis, and simultaneous TG-DSC analysis. Additionally, the energy of formation for these compounds is calculated using bomb calorimetry, based on the heat of combustion. The detonation performances of the compounds are determined through calculations using the EXPLO 5 software, and their sensitivities to external stimuli are evaluated.