The structure and composition of the oxide layer on the surface of 316L SS after exposure to high-temperature and high-pressure water with different concentrations of chloride ions (0, 50, and 200 μg/kg) for 500 h were characterized using various analysis methods and DFT calculations. The oxide layer had a double-layer structure. With the increase in chloride ion concentration, the thickness of the inner oxide layer became thinner, and the growth rates became similar. DFT results show that the Cl and O adsorption on the matrix and oxide surface differ. On the surface of the substrate, Cl adsorbs more readily than O. On the oxide surface, O adsorption is prior to Cl adsorption. After the formation of stable oxides, the effect of Cl is weakened, which corresponds to the approaching corrosion rate in different solutions after 500 h.

Although microbial self-healing concrete technology has been widely studied, limited attention has been paid to the effect of the dosage of microbial self-healing materials on concrete crack repair performance. To address this, this study investigates the influence of the dosage of microbial self-healing materials on the crack repair performance of concrete using planar thin-plate specimens. The results are summarized as follows: (1) Increasing the dosage of microbial self-healing materials effectively delays the initial cracking time of concrete specimens. When the dosage levels were 10%, 20%, and 30%, the initial cracking time was prolonged by 50%, 65%, and 70%, respectively, compared with the blank group without microbial addition. (2) After 28 d of water spraying and coating curing, the total crack area of concrete decreased significantly compared with that at the early age (1 d). For dosages of 0%, 10%, 20%, and 30% of microbial self-healing materials, the total crack area per unit surface area decreased by 12.2%, 21.9%, 22.7%, and 31.8%, respectively, compared with the initial stage. (3) Through X-ray diffraction (XRD), thermogravimetric analysis (TG/DTG), and morphological characterization, the presence of microbial mineralization products, including calcite and vaterite, on the concrete crack surfaces was confirmed.

The excessive fibrosis and immunosuppression characteristic of pancreatic ductal adenocarcinoma (PDAC) necessitate multi-targeted tumor microenvironment (TME) regulation. Multi-functional integration in these platforms raises preparation, stability and biosafety concerns, whereas structurally simple materials that enable equivalent TME modulation provide a streamlined solution. Herein, we report a carrier-free system (C8DSe) constructed solely from diselenide. Iron-free C8DSe effectively induces oxidative stress to trigger ferroptosis in tumor cells, while reversing TGF-β induced NIH-3T3 cells activation through simultaneous targeting of the TGF-β/Smad and antioxidant non-canonical NRF2-ARE pathways. It overcomes activated NIH-3T3 cells-mediated ferroptosis resistance by increasing ferrous ion content, inhibiting antioxidant systems, and promoting lipid peroxidation. In orthotopic fibrotic PDAC models, C8DSe exhibits potent antitumor efficacy through direct cytotoxicity, fibrosis reduction, and immune activation. These findings establish diselenide as multi-target agent for TME regulation, providing a template for single-compound therapies and advancing diselenide-based therapeutics.

Concrete, as a widely used construction material, suffers from performance degradation due to chloride penetration and sulfate attack in harsh environments. Conventional performance-enhancing methods are costly and emit high levels of carbon dioxide. This study modified graphene oxide (GO) with polycarboxylate superplasticizer (PCE) alone or PCE synergized with a rubber viscosity reducer, optimized dispersion (50 degrees C water bath for 1 h), and prepared C50 modified concrete (500 kg/m3 cementitious materials, w/b = 0.33). GO contents were 0%, 0.001%, 0.003%, 0.005%; a group with 8% reduced cementitious materials (460 kg/m3) was also tested. Results showed PCE-viscosity reducer synergy better dispersed GO, improving concrete workability. GO accelerated cement hydration via nucleation, refining C-S-H gel and reducing porosity. At 0.005% GO, 56 d drying shrinkage dropped by 29.3% vs. the blank, and 56 d chloride penetration electric flux was 586 C, meeting 100-year service life. Sulfate resistance also improved with higher GO content. Even with 8% less cementitious materials, modified concrete outperformed the blank. This provides support for GO's application in cement-based materials.

Coal gangue, as the industrial solid waste with the largest discharge and stockpile volume in China, has seen its resource utilization become a critical issue in promoting the green development of the coal industry. This paper systematically reviews the technical principles, process methods, product characteristics, and application prospects of producing ceramsite from coal gangue. It provides an in-depth analysis of the potential of coal gangue for ceramsite production and offers a detailed comparison of the technical features of different preparation processes. Research indicates that the chemical composition of coal gangue is highly similar to that of traditional raw materials for ceramsite, being rich in ceramic-forming components such as SiO₂ and Al₂O₃, as well as gas-generating substances like Fe₂O₃. By optimizing raw material ratios and improving preparation processes, high-performance ceramsite products can be produced. This paper also highlights the technical challenges currently faced in industrialization and outlines future development prospects, aiming to provide a reference for the high-value resource utilization of coal gangue.

In-situ polymerization is an effective approach to enhance the toughness of cementitious materials; however, the associated hydration retardation often leads to significant compressive strength loss. In this study, low-dosage nano-silica (NS) was incorporated into in-situ polymerization-modified cement systems (IPMCs) to regulate hydration kinetics and strengthen the polymer-cement interaction. Calorimetry, phase analysis, polymerization characterization, and microstructural observations revealed that 0.2% NS markedly accelerated hydration and increased the overall reaction degree. Consequently, the 28-day compressive and flexural strengths increased to 50.17 MPa and 17.73 MPa. These enhancements stem from the synergistic effects of NS, including its nucleationinduced hydration acceleration, pozzolanic production of additional C-S-H, and refinement of pore structure. Moreover, hydrogen bonding between NS and polymer chains increased the polymer network's crosslink density, while C-S-H formed from NS-driven rehydration bridged with polymer chains via Ca2+, reinforcing the organicinorganic interface. This coupled mechanism effectively offsets the hydration inhibition caused by polymerization and provides new insights for designing high-performance polymer-cement composites.

Copper components are prone to severe corrosion failure in aggressive tropical marine atmospheres, yet the fundamental growth-dissolution dynamics governing this process remain unclear. To resolve this issue, the atmospheric corrosion of TP2 copper exposed for 12 months in Wenchang City, China, was investigated through a multiscale approach that combined surface characterization, weight gain, electrochemical measurements and first-principles calculations. The process initiated with the formation of a Cu2O layer that thickened via the Point Defect Model mechanism, driven by the migration of Cu+ vacancies. Chloride ions (Cl-) spontaneously adsorbed onto the Cu2O surface, forming ionic Cu-Cl bonds and weakening the adjacent Cu-O bonds, which facilitated the dissolution of Cu2O and the release of Cu+ ions. These ions subsequently reacted with Cl-and OH-to form a bi-layer structure: an inner layer of Cu2O and an outer layer of Cu2O and Cu2Cl(OH)3. The corrosion products were protective, and over time, the protectiveness of the corrosion layer increased due to the progressive thickening of the inner Cu2O layer and an improvement in its crystal regularity. This study provides atomic-scale insights into the Cl--induced dissolution of Cu2O and elucidates the dynamic growth-dissolution process governing copper corrosion in aggressive marine environments.

The incorporation of microencapsulated phase change materials (MPCM) into cement-based materials has been a notable preference for passive storage of thermal energy in buildings. Existing researches show that the properties of cementitious materials will be dramatically affected due to the incorporation of microencapsulated PCM (MPCM). In this work, MPCM with n-octadecane as the core and SiO2 as the shell in nano-scale (Nano-MPCM) and micro-scale (Micro-MPCM) was synthesized and their effect on hydration and volume deformation of cement-based materials was systematically evaluated. The results showed that MPCM acts as a heterogeneous nucleation site and reduces the apparent activation energy of hydration, thus it accelerates the hydration process of cement. The hydration heat and chemical shrinkage of Nano-MPCM dosed pastes are higher than that of Micro-MPCM. The drying shrinkage is positively correlated with the dosage of Nano-MPCM, but inversely correlated with the dosage of Micro-MPCM. At a volume fraction of 15

Promoting construction waste utilization, this study explores using 30% mass fraction recycled micro powder (brick/concrete/hybrid) to replace cement in A03 foam concrete, as well as microbial foaming agents for insulation boards. The results show that hybrid micro powder foam concrete achieved higher compressive strength (0.7 MPa, 0.65 MPa) than pure brick (0.54 MPa) and concrete powder (0.61 MPa). For 30% hybrid micro powder insulation boards (brick:concrete ratios 2:8-8:2), when the ratio is 4:6, their performance meets JC/T 2200-2013 standards. At this point, the compressive strength is 0.43 MPa, the drying shrinkage is 0.29 mm, and the thermal conductivity 0.062 is W/(m·K). As the proportion of recycled brick powder increases, the material properties first improve and then decline, indicating that the proportion of recycled brick powder has a significant impact on the material's overall performance; within an appropriate range, optimal performance can be achieved.

In refractory multi-principal element alloys (RMPEAs), the rapid atomic diffusion occurring near dislocations facilitates local segregation and chemical ordering, leading to the formation of unique atomic environments capable of pinning dislocations on slip planes. However, previous atomistic simulations have largely overlooked how dislocations induce these unique atomic environments and influence the strengthening mechanism. In this study, we systematically investigate the atomic environments generated by dislocations during annealing and their effects on the mechanical properties of body-centered-cubic (BCC) RMPEAs using hybrid Monte Carlo/molecular dynamics simulations. A machine-learning interatomic potential is specifically trained for these RMPEAs. Our results reveal that the dislocation-core energy, elemental mixing energy, and dislocation-stress field collectively determine unique atomic environments, which strongly pin dislocations and significantly increase the critical resolved shear stress. As the atomic rearrangement near the dislocation core progresses, the enhanced pinning effect of edge dislocations arises from the continuous narrowing of the dislocation-core width, while the increased pinning of screw dislocations is attributed to the dislocation line becoming more kinked. In particular, edge dislocations exhibit a much stronger pinning effect than screw dislocations, consistent with recent experimental results.

The widespread use of Portland cement (OPC) has driven a continuous rise in CO2 emissions within the construction sector, posing a significant threat to the global climate. Low-carbon cements enriched in C3S2 and CS hold promise for drastically reducing CO2 output in the cement industry; however, the inherent lack of hydraulic reactivity in C3S2 and CS limits their practical application. Carbon capture, utilization, and storage (CCUS) technologies can rapidly enhance the mechanical performance of C3S2 and CS, thereby unlocking new avenues for low-carbon cement utilization. In this study, we evaluate the degree of carbonation and the post-curing compressive strength of low-calcium sulfoaluminate cements (C3S2/CS-C4A3 S) with varying C3S2 and CS contents under CO2 curing. The carbonation products, carbon sequestration capacity, micro-structural features, and pore architecture are characterized by XRD, TGA, SEM, and MIP analyses. The results indicate that when the C3S2 and CS contents reach 80 wt %, both the C3S2-C4A3 S (C1.5-80) and CS-C4A3 S (C-80) cements exhibit high carbonation rates and excellent mechanical performance. Specifically, the compressive strengths (CO2 sequestration capacities) of C1.5-80 and C-80 reach 46.64 MPa (0.16 g CO2/g) and 44.72 MPa (0.16 g CO2/g), respectively. XRD and SEM analyses reveal that the CaCO3 polymorph distribution strongly depends on the Ca/Si molar ratio of the silicate clinker: in the C3S2-C4A3 S system, aragonite and vaterite coexist with aragonite predominating, whereas in the CS-C4A3 S system vaterite is dominant, with only minor aragonite. This study thus provides valuable insights into the formulation, property tuning, and carbonation-curing efficiency of C3S2/CS-based cements, offering a practical reference for advancing carbon-neutrality in the cement industry.

Lead–zinc tailings (LZT), a low-value mining waste, pose significant environmental and health risks due to their massive accumulation. This study addresses the need for harmless and efficient treatment of LZT by successfully producing lightweight aggregates (LWA) from 100

The alkali-activated slag (AAS) system faces challenges due to its heavy reliance on commercial alkaline activators and the necessity of utilizing 100 % slag as precursor. Additionally, the substantial annual quantity of corn stalks limits disposal options for the corn stover ash (CSA) residues. This study investigates the feasibility of using CSA as a partial substitute for slag in AAS pastes. The effects of CSA calcination temperature, CSA dosage and alkali equivalent on the workability, hydration, shrinkage, and mechanical properties of AAS system with CSA are evaluated. The study indicates that incorporating CSA reduces the fluidity of AAS paste and prolongs the final setting time. Replacing 10 % ground granulated blast-furnace slag (GGBS) with CSA calcined at 600 degrees C enhances hydration and strength development, at a 4 % alkali equivalent. The 72 h cumulative heat release and the 28 d compressive strength increase by 19.9 % and 16.9 % respectively at this case. However, excessive CSA incorporation negatively impacts the hydration process of AAS system, leading a reduction of overall performance. CSA calcined at 600 degrees C exhibits the highest pozzolanic activity, providing the most significant improvements in hydration and mechanical properties of AAS paste with CSA. The results indicate that the CSA can be utilized as slag replacement in AAS paste and provides a feasible solution for the resource utilization of agricultural waste.

Ordinary Portland cement (OPC) is one of the most widely used building materials, but its hydration and setting are challenging to control on demand. In this article, phase change material (PCM) was successfully coated on the surface of sodium silicate (SS) using a facile vibration coating method to fabricate thermo-sensitive SS@PCM (SP) microcapsules. The microcapsules were utilized to accelerate the hydration and setting of cement paste using heat as a trigger on demand. The results showed that PCM powder can be melted and uniformly coated on the surface of SS to form a core-shell structure, and the heat-triggering temperature of SP microcapsules reached 60 degrees C. Before heat triggering, the PCM acts as a barrier preventing SS from reacting with OPC so that a long setting time, high fluidity and extremely low dynamic yield stress could be realized. After heat triggering, the PCM shell disintegrated, followed by the release of SS, the accelerator. SS and residual heat accelerated the hydration of OPC, as evidenced by the rapid increase of storage modulus, the rising of loss modulus, and the decrease of loss factor in several minutes. This led to the setting time decreasing from hours to minutes, losing fluidity, and gaining high static yield stress. The PCM usage of 15 % is beneficial for early hydration within 2-4 h and early compressive strength development. A 3D printing test verified that the paste could achieve the goal of setting on demand by simple addition of SP microcapsules and application of heating.

This study presents a novel cement-based composite exhibiting dual functionality for both absorbing electromagnetic waves and storing thermal energy. The composite was fabricated by incorporating nano-silica-encapsulated phase change microcapsules (n-OD@SiO2, MPCM) and a carbonyl iron powder/amorphous carbon composite absorber (CIP@SiO2@C). Its workability, hydration kinetics, electromagnetic properties, thermal behavior, mechanical performance, and internal microstructure were systematically characterized using isothermal calorimetry (TAM), a microwave vector network analyzer (VNA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and three-dimensional X-ray microtomography (Micro-CT). The results show that the combined addition of MPCM and CIP@SiO2@C markedly enhances both thermal regulation and electromagnetic wave absorption. The composite containing 20 vol% MPCM and 10 wt% CIP@SiO2@C achieved optimal electromagnetic performance, with absorption rates exceeding 80 % across nearly the entire 2-18 GHz and surpassing 85 % within 8-18 GHz. This formulation also demonstrated outstanding thermal regulation, reducing the heating rate by 73 % compared with ordinary cement. Although its mechanical strength was slightly lower than that of plain cement, the optimized composite maintained a 28-day compressive strength of 42.6 MPa, indicating satisfactory structural integrity. The findings underscore the success of the proposed cement-based composite in electromagnetic wave attenuation and thermal management, highlighting its strong potential for applications in electromagnetic pollution mitigation and energy-efficient building materials.

The utilization of aeolian sand (AS) as a substitute for river sand (RS) in ultra-high-performance concrete (UHPC) offers a sustainable solution to address natural sand resource shortages while enhancing AS utilization. This study systematically evaluates the influence of AS content (0-100% RS replacement by mass) on the workability, mechanical properties, and microstructure of UHPC under different curing regimes. All mixtures incorporate 0.65% by volume of straight steel fibers to ensure adequate fiber reinforcement. The results reveal that the spherical morphology, smooth surface nature, and fine particle size of AS enhance the matrix fluidity and reduce the early autogenous shrinkage of UHPC. By employing steam curing at 90 °C for 2 d followed by standard curing for 7 d (M3), UHPC samples with a 60% and 80% AS substitution achieve a compressive strength of 132.4 MPa and 130.8 MPa, respectively; a flexural strength exceeding 18 MPa; a porosity below 10%; and a gel pore content exceeding 60%. The steel fiber reinforcement contributes significantly to the flexural performance, with the fiber-matrix interface quality maintained even at high AS replacement levels. These findings highlight the feasibility of AS as an alternative fine aggregate in UHPC.

Preparing clinker-free cementitious materials by using lithium slag (LS) as silica-alumina precursors is an effective means to address environmental issues caused by LS emission. This paper attempted to explore the feasibility of preparing LS-based supersulfate cement (SSC) and the effect of phosphogypsum type (hemihydrate phosphogypsum (HPG) and dihydrate phosphogypsum (DPG)) on the early reaction characteristics of LS-based SSC was systematically investigated. The results showed that the setting time of LS-based SSC decreased with the increase of HPG content, while increased as DPG was dosed. HPG series behaved like Herschel-Bulkley fluid, whereas DPG series fitted well with Bingham mode. In comparison with DPG, an increase in HPG dosage led to a reduction in plastic viscosity and yield stress of LS-based SSC, and consequently, a decreasing tendency in fluidity was observed. HPG could more efficiently activate the hydration of LS than DPG thus leading to a higher compressive strength. At the age of 7 d, the strength exhibited an increasing trend with the increase of phosphogypsum dosage and the maximum value of the HPG series and DPG series could reach 26.8 MPa and 16.6 MPa, respectively. It is technically feasible to prepare SSC using LS and phosphogypsum.

Efficient grinding is one of the important means to reduce energy consumption in cement production, and the development of efficient grinding aids based on molecular structure design is currently a research hotspot. In this work, 2-acrylamido-2-methylpropanesulfonic acid (AMPS), hydroxypropyl acrylate (HPA), and diethylene glycol monovinyl ether (DEGVE) as monomers was applied to synthesize a novel low molecular weight polymer. A polymer-based grinding aid for cement clinker was prepared by incorporating polymeric polylol, and its structure-activity relationship was systematically evaluated. The results showed that the optimal performance was achieved when the amounts of initiator and chain transfer agent were 1.39% and 5.84%, respectively, and the ratio of n (DEGVE): n (AMPS): n (HPA) was 1:1.85:0.5. It should be noted that the optimal grinding performance is determined by the D50 value and the 45 µm sieve residue, not by the particle specific surface area or the strength of cement hydration, which are not the primary indicators for evaluating grinding performance. Compared with alcohol amine grinding aids, the prepared grinding aid could significantly optimize particle size distribution of cement. The volume fraction of particles above 0-32 µm and 64 µm was decreased by 1.5% and 51.7%, respectively, while increased by 59.5% for 32-64 µm; Compared with the alcohol amine grinding aid, the compressive strength of cement at 3 d and 28 d increased by 3.4% and 8.3%, respectively.

This study develops innovative cement-based composites with integrated electromagnetic wave absorption and thermal energy storage capabilities by incorporating Fe3O4/n-OD@SiO2@C core-shell microcapsules. These microcapsules feature a hierarchical structure consisting of a Fe3O4/n-octadecane (n-OD) composite core, an intermediate amorphous SiO2 layer, and an outer carbon coating. Structural and functional characterization using scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and vector network analysis (VNA) confirmed the structural integrity and multifunctionality of Fe3O4/n-OD@SiO2@C. The results demonstrate that the incorporation of Fe3O4/n-OD@SiO2@C significantly enhances both electromagnetic wave absorption and thermal energy storage in cement-based materials. The composite containing 50 vol% expanded polystyrene (EPS), 10 wt% Fe3O4/n-OD@SiO2@C, and 5 wt% adhesive exhibits optimal electromagnetic wave absorption performance, dissipating 80 % of electromagnetic wave absorption rate across the 8.5-18 GHz frequency spectrum. Simultaneously, this formulation demonstrates exceptional thermal regulation capabilities, decreasing the heating rate by 90.6 % compared to conventional Portland cement. While the addition of EPS and micro-capsules leads to a reduction in compressive strength, the composite still meets non-load-bearing structural requirements while enabling simultaneous electromagnetic wave absorption and thermal energy regulation. These findings highlight the potential of this material for advanced building envelopes in energy-efficient infrastructure, offering dual electromagnetic and thermal management capabilities.