Specific Pore Structure Research Articles

Injectable Antibacterial Hydrogel with Asiaticoside-Loaded Liposomes and Ultrafine Silver Nanosilver Particles Promotes Healing of Burn-Infected Wounds.

Post-injury infection and wound healing are recurrent daily life problems. Therefore, the necessity of developing a biomaterial with antibacterial and wound-healing properties is paramount. Based on the special porous structure of hydrogel, we modified recombinant collagen and quaternary ammonium chitosan and fused them with silver nanoparticles (Ag@mental-organic framework (MOF)) with antibacterial properties, and asiaticoside-loaded liposomes (Lip@AS) with anti-inflammatory/vascularization effects to form the rColMA/QCSG/LIP@AS/Ag@MOF (RQLAg) hydrogel. The prepared hydrogel possessed good sustainable release capabilities of Ag+ and AS and exhibited concentration-dependent swelling properties, pore size, and compressive strength. Cellular experiments showed that the hydrogel exhibited good cell compatibility and promoted cell migration, angiogenesis, and M1 macrophage polarization. Additionally, the hydrogels exhibited excellent antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) in vitro. In vivo, Sprague Dawley (SD) rats burn-wound infection model showed that the RQLAg hydrogel could efficiently promote wound healing and had stronger healing promoting abilities than those of Aquacel Ag. In summary, the RQLAg hydrogel is expected to be an excellent material for accelerating open wound healing and preventing bacterial infections. This article is protected by copyright. All rights reserved.

Effect of the combination of inverse opal photon superficial areaic crystal and heterojunction on active free radicals and its effect on the mechanism of photocatalytic removal of organic pollutants

For the inverse opal photocatalyst, hydraulic pressure and other problems caused by the ordered structure of the inverse opal photocatalyst make it difficult for the pollutants to enter the structure quickly and effectively, so the effective control of its structure has become an urgent problem to be solved. Here, multi-heterojunction inverse opal structure catalyst with multi-level branched pore structure is prepared by the sol-gel method. The special three-dimensional dendritic porous structure solves the problem that a pollutant solution is difficult to effectively enter a skeleton with the traditional ordered inverse opal photocatalyst. This structure can also lead to the nanocrystallization of TZS powders, thus promoting the formation of the intermediate product ZrTiO4 and optimizing the heterogeneous interface in the TiO2–ZrO2 heterojunction, thereby successfully constructing the multi-heterostructure and effectively improving the redox ability. Furthermore, by adjusting the loading amount of TZS, the matching of the heterojunction and the inverse opal structure can be effectively controlled, the matching of the photonic band gap and the forbidden bandwidth can be effectively adjusted, and the degradation efficiency is greatly improved. This study provides a new idea for effective collaboration between multi-heterogeneous interfaces and 3D branch fractal structures.

Engineering of N, P co-doped hierarchical porous carbon from sugarcane bagasse for high-performance supercapacitors and sodium ion batteries

Porous carbon is one of the most promising electrode materials for energy conversion and storage devices due to its high specific surface area, low cost, sustainability, appropriate charging/discharging voltage platform and high interlayer spacing. However, the disadvantage of insufficient energy storage capacity frustrates its wide applications. Herein, a novel N, P co-doped porous carbon derived from sugarcane bagasse (SBNPk) was prepared by hydrothermal method combined with KOH activation and carbonization, and was applied to supercapacitors (SCs) and sodium-ion batteries (SIBs). The SBNPK possesses a special hierarchical porous structure, improved surface area, larger interlayer spacing, and moderate N, P doping level. Specifically, the SBNPk carbonization at 600 °C (SBNPk-600) exhibits the highest specific capacitance (356.4 F g−1 at 1 A g−1), good rate capability and excellent cycle stability (5% loss over 10,000 cycles) in a three-electrode system. Further assembled in a symmetrical two-electrode system, the SBNPK-600//SBNPK-600 can still provide a higher energy density of 6.5 Wh kg−1 at 251.9 W kg−1 and superior cycle performance (96.5% of capacitance retention at 2 A g−1 after 20,000 cycles). Surprisingly, the SBNPK-600 as an anode for SIBs also delivers a high reversible capacity of 304.1 mAh g−1 at 25 mA g−1 and excellent cycle performance (225.7 mAh g−1 after 1000 cycles at 500 mA g−1), indicating its superior sodium storage capability. This work provides a simple and new way to enhance the electrochemical performance of biomass waste-derived carbon by heteroatom doping, which is helpful to further boost its application in the field of energy storage.

β-cyclodextrin-based porous carbon with tunable pore and interface allows efficient removal of chlorophenols from aqueous solution

Chlorophenols (CPs), a kind of important intermediate for fine chemicals, exists widely in the aqueous environment and poses a significant danger to humans. Therefore, developing advanced materials to enable the effective capture of CPs is highly desired. Herein, β-cyclodextrin-based porous carbon (CPAC) with exceptional capacities for CPs has been designed and tested. These porous carbon adsorbents were successfully synthesized via stepwise carbonization, affording abundant N and O functional groups, high surface area (as high as 3982 m2·g−1) and controlled pore size to optimize for rapid CPs uptake. According to the CPs uptake measurements, CPAC exhibited exceptional CPs adsorption performance. CPAC showed high adsorption capacities (1085.08 mg·g−1 for 2,4,6-trichlorophenol) and fast adsorption kinetics for CPs. CPAC can effectively recover multi-component CPs from complex aqueous media, and the special pore structure reduces the competitive adsorption between CPs. And the recyclability studies showed that CPAC maintained its structural integrity and the initial CPs uptake capacity, highlighting its potential for practical application. Besides, DFT calculations indicate that hydrogen bonding and π-π interactions are key factors. Among them, the molecular conformation of CPs and the number of chlorine atoms on phenol play a crucial role in the adsorption behavior and adsorption energy.

Efficient removal of methylene blue via two-step modification hazelnut shell biochar: Process intensification, kinetics and thermodynamics

Porous carbon materials with ultra-high specific surface area and adjustable pore structure characteristics were prepared from food industry waste hazelnut shells for the adsorption of methylene blue (MB) wastewater by two-step activation by impregnation with ZnCl2 followed by chemical activation with KOH. The Fusso effect, which can reduce the size of MB molecules, was further used to enhance the adsorption of MB on porous carbon. The results show that both HSBC-a and HSBC-a-b have ultra-high specific surface area (2979.59 m2/g for HSBC-a, 2882.73 m2/g for HSBC-a-b). The mesopore ratio of HSBC-a-b (Vmeso/Vtotal % = 14.05%) was doubled compared to HSBC-a. It showed an excellent adsorption performance of 694.03 mg/g for MB. It showed a fast adsorption kinetics and the adsorbed amount increased to 882.46 mg/g at 0.1 M NaCl solution. In addition, adsorption processes were studied using adsorption kinetics and adsorption isotherm model fitting. The results of this research confirm that hazelnut shell is a kind of promising and sustainable porous carbon raw material, and its ultra-high specific surface area and adjustable pore structure characteristics are favorable for the efficient treatment of MB from dyeing wastewater. This work could provide potential guidance for the high-value utilization of waste hazelnut shell biochar.

Intumescent closed-cell porous molecular engineering towards high flame retardancy and ultra-low smoke release epoxy resin

Wide applications of high-flammable epoxy resin (EP) bring potential fire risks with huge heat and smoke hazards. Although effective strategies for flame retardancy and heat suppression have been developed, there are still few measures for reducing smoke release synchronously. Herein, 2-aminobenzimidazole modified ammonium polyphosphate intumescent flame-retardant co-curing agent (ABMZ-APP), possessing excellent char-forming performance, is designed and endows EP/ABMZ-APP thermosets with excellent flame retardancy, heat suppressing, and smoke suppressing performance. It is worth mentioning that the total smoke production (TSP), and maximum smoke density (DSmax) of EP with 20 wt% ABMZ-APP decrease by 73.2%, and 67.6%, respectively. Deep investigation illustrates EP/ABMZ-APP suppresses the smoke by obstructing soot-precursor transfer through the special porous char structure, rather than altering the chemical changes in nucleation and growth processes of mature soot. Meanwhile, the closed-cell porous char layers, acting as physical barriers, obstruct the heat/fuels transfer simultaneously which is beneficial for suppressing sustained burning.

One-step synthesis of porous thin-layered graphitic carbon nitride for enhanced photocatalytic dye degradation

The application of graphitic carbon nitride (g-C3N4) as a non-metallic photocatalyst for removing harmful pollutants in the wastewater environment has received considerable attention in recent years. Nevertheless, its low activity is primarily restricted by a high rate of charge carrier recombination. Herein, a green and straightforward method for synthesizing small-sized porous thin g-C3N4 nanosheets directly from urea solution has been developed. This new photocatalyst can effectively remove 99.3% of rhodamine B within 15 min, exhibiting a degradation rate 16.8 times greater than that of conventionally synthesized bulk g-C3N4, under visible light irradiation. Additionally, this photocatalytic efficiency is comparable or even superior to that of previously reported literature, while requiring significantly less catalyst usage. From the experimental results, we have confirmed that the outstanding structural property as well as the stronger oxidizability of the valence-band holes (h+) are responsible for its greater photocatalytic activity. Its increased specific surface area and abundant pore structure significantly improve contaminant adsorption and charge separation and transfer. Meanwhile, the positive shift of the valence band enhances the oxidation of photogenerated h+, resulting in higher photocatalytic activity. This work can provide newly insights for designing highly efficient and easily-constructed g-C3N4 photocatalysts for practical photocatalytic water treatment applications.

Polycaprolactone with multiscale porosity and patterned surface topography prepared using sacrificial 3D printed moulds: Towards tailor-made scaffolds

Biocompatible three-dimensional porous scaffolds are widely used in multiple biomedical applications. However, the fabrication of tailor-made 3D structures with controlled and combined multiscale macroscopic-microscopic, surface and inner porosities in a straightforward manner is still a current challenge. Herein, we use multimaterial fused deposition modeling (FDM) to generate poly (vinyl alcohol) (PVA) sacrificial moulds filled with poly (Ɛ-caprolactone) (PCL) to generate well defined PCL 3D objects. Further on, the supercritical CO2 (SCCO2) technique, as well as the breath figures mechanism (BFs), were additionally employed to fabricate specific porous structures at the core and surfaces of the 3D PCL object, respectively. The biocompatibility of the resulting multiporous 3D structures was tested in vitro and in vivo, and the versatility of the approach was assessed by generating a vertebra model fully tunable at multiple pore size levels. In sum, the combinatorial strategy to generate porous scaffolds offers unique possibilities to fabricate intricate structures by combining the advantages of additive manufacturing (AM), which provides flexibility and versatility to generate large sized 3D structures, with advantages of the SCCO2 and BFs techniques, which allow to finely tune the macro and micro porosity at material surface and material core levels.

Preparation of Reusable Porous Carbon Nanofibers from Oxidized Coal Liquefaction Residue for Efficient Adsorption in Water Treatment.

Porous carbon nanofibers are commonly used for adsorption processes owing to their high specific surface area and rich pore structure. However, the poor mechanical properties of polyacrylonitrile (PAN)-based porous carbon nanofibers have limited their applications. Herein, we introduced solid waste-derived oxidized coal liquefaction residue (OCLR) into PAN-based nanofibers to obtain activated reinforced porous carbon nanofibers (ARCNF) with enhanced mechanical properties and regeneration for efficient adsorption of organic dyes in wastewater. This study examined the effects of contact time, concentration, temperature, pH, and salinity on the adsorption capacity. The adsorption processes of the dyes in ARCNF are appropriately described by the pseudo-second-order kinetic model. The maximum adsorption capacity for malachite green (MG) on ARCNF is 2712.84 mg g-1 according to the fitted parameters of the Langmuir model. Adsorption thermodynamics indicated that the adsorptions of the five dyes are spontaneous and endothermic processes. In addition, ARCNF have good regenerative performance, and the adsorption capacity of MG is still higher than 76% after 5 adsorption-desorption cycles. Our prepared ARCNF can efficiently adsorb organic dyes in wastewater, reducing the pollution to the environment and providing a new idea for solid waste recycling and water treatment.

Reactive adsorption desulfurization of FCC gasoline over self-sulfidation adsorbent

NiSO4/ZnO-Al2O3-SiO2 adsorbent, as a novel reactive adsorption desulfurization (RADS)adsorbent, has self-sulfidation ability and high desulfurization performance when treating model fuel. However, the RADS performance of the adsorbent under FCC gasoline feedstock is not well understood. Here, we compare the performance of the adsorbent under FCC gasoline with model fuel to test the effect of the hydrocarbon composition of the feedstock. The complex composition of FCC gasoline makes it sensitive to the nickel loading amount of the adsorbent. Under the influence of specific surface area and pore structure, the adsorbent loaded with 3 wt% nickel shows better desulfurization activity when treating FCC gasoline. As hydrocarbons in FCC gasoline compete with sulfur compounds for active Ni sites, the reaction conditions have been tested and optimized to achieve deep desulfurization while maintaining low olefin loss to ensure the octane number of the product. By experimental tests and characterization, it has been proved that NiSx and NiO acted as active Ni sites of the adsorbent. Based on these observations, the mechanism of RADS of FCC gasoline over NiSO4/ZnO-Al2O3-SiO2 adsorbent has been proposed, which provides theoretical support for the development of new adsorbents and the optimization of RADS process.

Construction of nitrogen-doped graphene-based ternary magnetic composite aerogel towards excellent electromagnetic absorption in the Ku-band

The development of advanced electromagnetic wave (EMW) absorbing materials with broad bandwidth, strong absorption, low filler loading ratio and small thickness remains a great challenge. In this work, nitrogen-doped reduced graphene oxide/multi-walled carbon nanotubes/hollow nickel ferrite (NRGO/MWCNTs/hollow NiFe2O4) ternary magnetic composite aerogel with the ultralow bulk density was synthesized via the two-step route of solvothermal synthesis and hydrothermal self-assembly. Results of microscopic morphology characterization showed that as-synthesized binary and ternary magnetic composite aerogels exhibited the special three-dimensional hierarchical porous network structure. Moreover, the EMW absorption performance of ternary composite aerogel was obviously enhanced in comparison with NRGO/MWCNTs and NRGO/hollow NiFe2O4 binary composite aerogels. Remarkably, the attained NRGO/MWCNTs/hollow NiFe2O4 ternary composite aerogel showed the maximum absorption bandwidth of 6.7 GHz (11.3–18.0 GHz) and robust absorbing intensity of − 42.8 dB at a thin matching thickness of 2.0 mm and a low loading ratio of 12.5 wt%. It was worth noting that when the matching thickness was slightly increased to 2.1 mm, the optimal minimum reflection loss could reach − 69.0 dB. The special hierarchical porous network structure and magnetodielectric synergy in the ternary composite aerogel optimized the impedance matching, and notably enhanced the EMW absorbing capacity. Therefore, this work could contribute to the construction of graphene-based hybrid nanocomposites as advanced EMW absorbers.

Facile synthesis of a novel Zn2Ti3O8 aerogel with porous structure for high-efficient degradation of antibiotics under simulated sunlight

Photocatalytic degradation, as advanced oxidation methods with high efficiency and good stability, is considered a promising method to alleviate antibiotic pollution. Herein, we prepared a novel Zn2Ti3O8 aerogel by a simple sol-gel method based on the advantages of the abundant pore structure of aerogel material and the high photocatalytic activity of zinc titanate. The Zn2Ti3O8 aerogel shows a typical homogeneous structure and low band gap width (3.32 eV), which could achieve photogenerated carrier separation and transfer under simulated sunlight. The material has high specific surface area (120.1 m2/g) and abundant pore structure, which can provide multiple diffusion channels for pollutant molecules and generate massive reactive sites. In the absence of cocatalysts, the prepared Zn2Ti3O8 aerogel can achieve more than 95% degradation efficiency for 50 mg/L of ofloxacin (OFL) contaminated solution in 60 min. Electrochemical impedance spectroscopy (EIS) and transient photocurrent test results display that Zn2Ti3O8 aerogel exhibits the highest photocurrent density and lower charge transfer resistance. Meanwhile, the results of density functional theory (DFT) are consistent with the characterization results of electron spin resonance (ESR). The ·OH and ·O2− generated in the catalytic reaction could attack OFL molecules from different regions to achieve the purpose of decomposition. We believe that the as-prepared Zn2Ti3O8 aerogels are expected to be used in the practical treatment of catalytic degradation of OFL and other antibiotic pollutants.

One-step synthesis of nitrogen and sulfur co-doped hierarchical porous carbon derived from acesulfame potassium as a dual-function agent for supercapacitors and lithium‑sulfur batteries

Acesulfame potassium (AK) is an artificial sweetener that contains N and S functional groups in its organic moiety and is suitable as porous carbon precursor. In this study, AK derived carbon (AKC) was obtained via direct carbonization and in situ doping without additives under the dual conditions of inert gas protection and high temperatures. The obtained AKCs exhibited high porosity structure with a specific surface area of 2043 m2 g−1 and 3.22 wt% N and 8.61 wt% S dual heteroatom doping. When applied to the supercapacitor electrode, the AKC ensured a high capacitance of 264 F g−1 at 0.5 A g−1, which maintained 86.1 % of the initial capacitance after 5000 cycles at 5 A g−1, and an ultra-high energy density of 16.3 Wh kg−1 in a full cell device. By analyzing its application in the lithium‑sulfur battery cathode, the S-loaded AKC exhibited a high capacity of 1075 mAh g−1 at 0.1C, and 490.5 mAh g−1 after 150 cycles with 66.5 % of capacity retention. The excellent performance of AKC can be attributed to its high specific surface area, pore structure, and sulfur and nitrogen co-doping combine effect. Overall, AKCs exhibited excellent electrochemical performances, thereby proposing a new synthetic strategy of preparing dual heteroatom doped porous carbon for high-performance electrode materials through a single precursor and low-cost perspective.

Sensitive and Selective Electrochemical Detection of Lead(II) Based on Waste-Biomass-Derived Carbon Quantum Dots@Zeolitic Imidazolate Framework-8.

An electrochemical sensor based on carbon quantum dots (CQDs) and zeolitic imidazolate framework-8 (ZIF-8) composite was fabricated to detect lead(II). The CQDs (2.47 ± 0.52 nm) were synthesized from platanus acerifoli leaves by carbonization and the hydrothermal method. Under the optimal conditions, the fabricated electrochemical sensor had excellent performance in detecting Pb2+. The linear range for Pb2+ was 1 nM-1 μM, and the limit of detection (LOD) was 0.04 nM and the limit of quantification (LOQ) was 0.14 nM. Moreover, when the solution contained Pb2+ and Cd2+, the linear range for Pb2+ was 50 nM to 1 μM and the LOD was 0.02 nM. When the solution contained Pb2+ and Cu2+, the linear range for Pb2+ was 50 nM-750 nM and LOD was 0.07 nM. Furthermore, even if the solution contained Pb2+, Cd2+ and Cu2+, the linear range for Pb2+ was 50 nM-1 μM and the LOD was 0.04 nM. The X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectrometer (FTIR) and Brunauer-Emmet-Teller (BET) results indicated that the composite electrode materials had abundant oxygen-containing functional groups, a large specific surface area and pore structure, which are conducive to the adsorption of heavy metal ions and improve the detection performance.

Fabrication of core-shell structure NiFe2O4@SiO2 decorated nitrogen-doped graphene composite aerogels towards excellent electromagnetic absorption in the Ku band

The fabrication of advanced electromagnetic wave absorbents with wide bandwidth, robust absorption and small filling ratio remains a great challenge. In this work, the ternary composite aerogel of nitrogen-doped reduced graphene oxide/nickel ferrite@silicon dioxide modified by amino groups (NRGO/NiFe2O4@m-SiO2) was synthesized via the three-step route of solvothermal synthesis, Stöber method and hydrothermal self-assembly. Microscopic morphology characterization results indicated that the acquired binary and ternary magnetic composite aerogels exhibited a special three-dimensional porous network architecture. Moreover, the electromagnetic absorbing capacity of NRGO/NiFe2O4 composite aerogel could be obviously enhanced by coating SiO2 and modifying amino groups on the surfaces of SiO2. Remarkably, the as-fabricated NRGO/NiFe2O4@m-SiO2 composite aerogel possessed the broadest effective absorption bandwidth of 7.04 GHz (10.96–18.0 GHz) and robust absorbing intensity of −30.8 dB at 2.1 mm under a small filling ratio of 12.5 wt%. It was worth mentioning that the optimal minimum reflection loss could reach −56.0 dB when the matching thickness was increased to 3.4 mm. Besides, a minimum radar cross section value of −51.1 dB m2 could be achieved in the far-filed condition. The special porous network structure and magnetodielectric synergy in the ternary composite aerogel optimized the electromagnetic impedance, and notably enhanced the electromagnetic absorbing capacity. It was believed that this study would provide a novel approach for the construction of highly efficient carbon-based electromagnetic wave absorbers.

Impact of Surface Structure on SEI for Carbon Materials in Alkali Ion Batteries: A Review

Due to their low cost, suitable working potential and high stability, carbon materials have become an irreplaceable anode material for alkali ion batteries, such as lithium ion batteries, sodium ion batteries and potassium ion batteries. During the initial charge, electrolyte is reduced to form a solid electrolyte interphase (SEI) on the carbon anode surface, which is an electron insulator but a good ion conductor. Thus, a stable surface passivation is obtained, preventing the decomposition of electrolyte in the following cycles. It has been widely accepted that SEI is essential for the long-term performance of batteries, such as calendar life and cycle life. Additionally, the initial coulombic efficiency, rate capability as well as safety of the batteries are dramatically influenced by the SEI. Extensive research efforts have been made to develop advanced SEI on carbon materials via optimization of electrolytes, including solutes, solvents and additives, etc. However, SEI is produced via the catalytic decomposition of electrolyte by the surface of electrode materials. The surface structure of the carbon material is another important aspect that determines the structure and property of SEI, which little attention has been paid to in previous years. Hence, this review is dedicated to summarizing the impact of the surface structure of carbon materials on the composition, structure and electrochemical performance of the SEI in terms of surface atoms exposed, surface functionalization, specific surface area and pore structure. Some insights into the future development of SEI from the perspective of carbon surface are also offered.

Imaging Solvent‐Triggered Gaseous Iodine Uptake on Single Covalent Organic Frameworks

AbstractCovalent organic frameworks (COFs) are promising solid absorbents for the treatment of gaseous iodine. However, extensive efforts are still focused on empirical optimizations of specific binding sites and pore structures in COFs, and the chemical control of gaseous iodine uptake on COFs remains challenging. In this study, the chemically triggered sorption properties of COF‐300 for I2 vapors at the single‐particle level with the dark‐field microscope (DFM) are explored. The present operando single‐particle DFM imaging method enables the direct visualization of an adsorption activity transformation from inactive COF‐300 to active solvated COF‐300 toward gaseous I2 vapors. Exploiting the useful reaction information from time‐lapsed DFM images, the tunable adsorption performance of solvated COF‐300 is quantitatively compared by various solvents. The results illustrate that the isopropanol (IPA)‐solvated COF‐300 achieves the optimum adsorption capacity for I2 among the absorbents. The reaction mechanism is elucidated to be the channel size enlargement and modification of internal surface chemistry in the IPA‐solvated COF‐300, producing a stable I2/IPA‐solvated COF‐300 complex after the sorption reaction. The present chemical control of the sorption behavior of COF‐300 revealed by DFM opens up a new fundamental paradigm for rationally developing high‐performance COF‐based absorbents for removing I2 vapors.

Metal-organic framework-derived molybdenum phosphide@mesoporous carbon composite for electrochemical acetaminophen detection

Electrochemical methods have attracted great attention in the detection of acetaminophen (AP) due to their high sensitivity, rapidity, and simplicity. Molybdenum phosphide (MoP) with excellent catalytic activity and redox property has been widely used for electrochemical applications. In this work, MoP nanoparticles loaded with mesoporous carbon (MoP@C-D2) were successfully synthesized and characterized by powder X-ray diffraction (PXRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) method, and X-ray photoelectron spectroscopy (XPS). It is shown that the temperature rising process and the amount of polyoxometalate and NaH2PO2 can significantly affect the specific surface areas and pore structures of the product, thereby affecting their sensing performances. Structural studies indicated that MoP nanoparticles in MoP@C-D2 were uniformly dispersed in mesoporous carbon matrix, endowing the composite high conductivity, large specific surface area, and good catalytic activity. MoP@C-D2 modified electrode showed a wide linear detection range of 1.24–1071.4 μM, the detection of limit (LOD) of 0.008 μM, high stability, and good selectivity for AP detection. In addition, the constructed electrode can also be used to detect the content of AP in commercial medicine. This work extends the application of mesoporous MoP-based composite in electrochemical sensing.

Experimental study on the interaction mechanism between fracturing fluid and continental shale oil reservoir

ABSTRACT Onshore shale oil is difficult to develop due to its special pore structure and low permeability characteristics. Artificial fracturing causes a large amount of fracturing fluid to intrude into the reservoir, resulting in a complex reservoir seepage pattern. Therefore, this paper aims to explore the changes in the reservoir at the macro and micro levels due to the interaction between fracturing fluids and shale oil reservoirs. For this, four rock samples from shale oil reservoirs and two fracturing fluids commonly used in the mine were used. Then, core repulsion, scanning electron microscopy, X-ray diffraction and CT scanning experiments were carried out successively. The following results were derived from our analyses. (1) Permeability of the rock samples was reduced by an average of 24.47% after replacement by fracturing fluid, while the experimental groups with larger fluid-grain sizes and well-developed fracture networks suffered more significant solid-phase damage and fluid-phase trapping. (2) Fracturing fluids have different effects on fractures at different scales; large fractures (>7.71 μm) were widened, while small fractures (<3.47 μm) were shrunk or even plugged. (3) Based on the water-sensitive effect, fracturing fluids can disperse and transport clay minerals, resulting in fluid-phase damage and an average decrease of 14.33% in clay content in the reservoir. (4) Analysis of the digital core model shows that fracturing fluid intrusion and retention can cause solid-phase damage to the reservoir matrix, with 38.14% and 60% damage to the pore and throat channels, respectively. This paper uses a combination of physical experiments and numerical analysis to investigate the interaction mechanism between fracturing fluids and shale oil reservoirs from both microscopic and macroscopic perspectives. Overall, the results of this study provide experimental support for future studies on the seepage characteristics of this type of reservoir and the design of fracturing construction schemes.

Effects of volatiles and active AAEMs interaction with char on char characteristics during co-pyrolysis

The interactions between volatile substances (volatiles and volatile alkali and alkaline earth metals) released from pyrolysis and char have a crucial influence on the co-gasification process. The influence mechanism of volatiles-char interaction and volatile substances-char interaction in the co-pyrolysis of coal (RSM) and corn stover (RCS) was studied. The findings indicated that volatiles-char interaction suppressed the progression of specific surface area (SSA) and pore structures of char. Volatile active alkali and alkaline earth metals (Ac-AAEMs) of RCS/RSM attenuated the unfavorable effects of volatiles and facilitated the progression of pore structures and SSA of coal/RCS char. Besides, volatiles could react with char through small aromatic ring structures and oxygen-containing groups. The presence of volatile Ac-AAEMs could inhibit the depletion of small aromatic ring structures and oxygen-containing groups caused by volatiles-char interaction. Among them, RCS volatile Ac-AAEMs suppressed the consumption of 11% oxygen-containing groups. RSM volatile Ac-AAEMs inhibited the depletion of 4% oxygen-containing groups. Finally, RCS volatiles-char interaction could inhibit the reactivity of RSM char. The existence of RCS volatile Ac-AAEMs could alleviate the inhibition of volatiles and significantly promote the reactivity of RSM char. Nevertheless, the volatiles and volatile Ac-AAEMs from RSM exhibited minor impacts on RCS char reactivity.