In cold and high-salt environments, the combined effects of ice accretion and chloride ion ingress pose severe threats to the service life of cementitious infrastructure, necessitating durable, multifunctional surface modifications that go beyond conventional coatings. This study introduces a magnetically induced strategy using fluorinated organosilane copolymer-coated magnetic microspheres to simultaneously enhance chloride resistance and anti/de-icing performance. Under an external magnetic field during hydration, these microspheres migrate to the cement near-surface region, forming an integral hydrophobic layer chemically anchored via Si–O–Si bonds. The optimized modified cement yields a 14.91-fold increase in water contact angle relative to the reference, maintaining exceptional stability after aggressive aging. Concurrently, it reduces chloride penetration by 37.34% and boosts compressive strength by 24.22%, attributed to microstructural densification and pore refinement. Furthermore, the surface significantly delays ice formation and reduces adhesion strength, while accelerating melting under solar irradiation through synergistic hydrophobicity and photothermal conversion. This integrated approach provides a general durable and effective solution with tailored functionality for infrastructure exposed to harsh cold and high-salt environments.

Autogenous shrinkage presents a significant challenge to the durability of high-performance cementitious composites due to their inherently low water-to-binder ratios. While superabsorbent polymers (SAPs) offer internal curing, they inherently introduce large voids that compromise mechanical integrity. To address this limitation, this study proposes a novel Reactive Hydrogel Precursor Solution (RHPS) based on 2-acrylamido-2methylpropanesulfonic acid (AMPS). A multi-scale experimental program integrated with molecular dynamics (MD) simulations was conducted to elucidate the underlying mechanism. MD results demonstrate that unlike acrylic acid, the sulfonate groups in AMPS exhibit weak adsorption on tricalcium silicate surfaces, ensuring uniform dispersion of monomers in the pore solution for effective network formation. Macroscopically, the incorporation of 3% RHPS reduces 7-day autogenous shrinkage by 99.6%, effectively mitigating dimensional instability. Mechanistically, low-field NMR reveals a dynamic water regulation process: the polymer network initially sequesters mobile water to mitigate early heat evolution and subsequently releases it to sustain continuous hydration. This mechanism, combined with the polymer bridging effect, refines the pore structure that decreasing total porosity to 8.24% at 28 days while the incorporation of soft polymer domains resulted in a moderate reduction in compressive strength, the flexural strength was enhanced by 26.1%. This work establishes a new and effective strategy for internal curing that simultaneously controls shrinkage and refines microstructure without introducing voids.

Achieving simultaneous improvement in strength and toughness remains a long-standing challenge in cementitious materials due to their inherently brittle nature and the strength-toughness trade-off. This study proposes a novel synergistic modification strategy that combines acrylamide (AM) in-situ polymerization with nano-silica (NS) incorporation to overcome this limitation and develop high-performance cementitious composites. The synergistic effects of AM in-situ polymerization and NS incorporation on the hydration behavior, microstructure, mechanical performance, and durability properties of cementitious materials were systematically investigated. Results show that NS effectively offsets the hydration retardation induced by in-situ polymerization of AM and promotes the formation of additional C-S-H gel. Microstructural analysis demonstrates that the rigid C-S-H skeleton and flexible PAM network interpenetrate to form a dual-network architecture, which enhances both load-bearing capacity and crack resistance. Compared with the reference sample, NS1-AM2 sample exhibits a refined pore structure, with a 58.0 % reduction in critical pore size and an 82.0 % decrease in capillary-pore fraction. The NS-AM composites demonstrate dual enhancements in strength and toughness with NS1-AM1 sample showing compressive strength and flexural strength 9.7 % and 47.0 % higher than the control samples, respectively. The capillary absorption coefficient of NS-AM composites decreased by up to 48.0 %, confirming improved impermeability and durability. This synergistic approach provides a viable route for designing next-generation cementitious materials with balanced strength, toughness, and durability.

Carbide slag (CS), a calcium and alkali-rich industrial byproduct, shows potential for CO2 capture but is limited by the low dissolution rate of calcium ions during carbonation. This study proposes a triethanolamine (TEA)modified carbonation approach to enhance CO2 uptake efficiency and application of CS in cement-based materials. Results show that the addition of 10 g/L TEA significantly enhances the CO2 uptake of CS from 12.58 % (without TEA) to 21.35 % by accelerating calcium ion dissolution during the carbonation process. Besides, TEAmodified carbonation also promotes the formation of needle-like calcite with a high aspect ratio, which could be attributed to the site-selective adsorption of TEA molecules on the planes of CaCO3 crystals based on the molecular modeling analysis. Considering the incorporation of TEA-modified carbonated CS (TCCS) into cementbased materials, the compressive strengths are significantly increased by 10-25 % and 5.2-12.6 % at 1 d and 28 d, respectively. Further analysis indicates that the adsorbed TEA-CO2 complexes on the surface of TCCS facilitate the formation of nano-CaCO3 particles and enhance the dissolution of aluminate phases, which can enhance cement hydration and increase the formation of hydration products. This work provides new insights into alkanolamine-regulated carbonation mechanisms and offers a sustainable strategy for CO2 capture and solid waste utilization in low-carbon cementitious materials.

Improving cement waterproof durability is crucial for enhancing their long-term performance in corrosive environments. In this study, hydrophobic magnetic microspheres (PFnMA@nano-Fe3O4) were synthesized by coating nano-Fe3O4 particles with a fluoropolymer and subsequently directed to the cement surface using an external magnetic field. This resulted in a significant increase in water contact angle (133.66°, a 27.81-fold increase) and compressive strength (37.70 MPa, a 13.45% increase), balancing hydrophobicity and mechanical performance. Modified cement exhibited a 37.40% reduction in water absorption and a 94.83% improvement in chloride ion penetration resistance. Unlike conventional cement waterproofing coatings, this method integrates hydrophobic functionality within the cement matrix via in situ enrichment, eliminating interfacial incompatibility and ensuring long-term stability of the waterproofing effect. After undergoing waterproof durability tests (such as immersion, spraying, UV exposure and abrasion), the modified cement still maintains excellent hydrophobicity. This approach offers a promising strategy for developing durable and sustainable cementitious materials.

Triethanolamine (TEA) is widely used to enhance early strength in cement-based materials; however, its effects on the principal binding phase, calcium silicate hydrate (C-S-H), remain unclear. In the study, the effects of TEA on the micromechanical properties of C-S-H phases with varying densities within hardened cement paste (hcp) were investigated using microscratch testing. Results indicate that the addition of 0.02 % TEA (by mass ratio of cement) decreased the volume fractions of low-density and high-density C-S-H phase, while significantly increasing the volume fraction of ultra-high-density C-S-H phase by approximately 70 %. This increase in the volume fraction of UHD C-S-H phase mainly arises from the formation of lamellar-type Ca(OH)2 with an increased specific surface area in the presence of TEA, which enhances the interfacial contact between Ca(OH)2 and C-S-H gel, thereby promoting the formation of ultra-high-density C-S-H. The TEA-induced formation of C-S-H gel with a higher density enhances the development of a tougher and more stable bonding framework within the cement matrix. Consequently, the 1 d compressive strength of hcp increased by 32 % with the addition of 0.02 % TEA. This work offers new insights into the role of TEA in regulating the C-S-H phase in cement-based systems and highlights the utility of microscratch as an effective multiscale characterization technique, thereby providing a valuable reference for future research.

Reducing resource waste due to structural degradation and limited lifespan of cement is a key challenge in developing a low-carbon economy. A major contributor to cement deterioration in natural environments is chloride ion-induced reduction in strength and durability. This study explores the synergistic use of cationic polymer-grafted nano-silica (SiO2-g-PDEMAQA, NS), silica fume, and fly ash to enhance cement durability and compressive strength. At optimal dosages (1.0 wt% NS, 5.0 wt% silica fume, and 20.0 wt% fly ash), a 97.50 % strength increase and an 18.11 % improvement in chloride ion resistance were achieved. Compared to samples containing only 1.0 wt% NS, the combined additions resulted in a further 2.19 % improvement in chloride ion permeability resistance and an 87.71 % increase in compressive strength, significantly enhancing the durability of cementitious materials. This improvement is attributed to both the 'micro-filling' effect and high pozzolanic activity of silica fume and fly ash, which promote cement hydration and refine the internal pore structure. Furthermore, when used in conjunction with silica fume or fly ash, NS enhances performance not only by promoting hydration but also by increasing chloride ion adsorption through its surface-modified cationic polymer in the alkaline environment. This synergistic approach offers a viable strategy for improving cement performance and durability, contributing to sustainable cement development and carbon emission reduction, with potential for versatile application in construction systems.

Conductive gels hold promise for human‐machine interaction (HMI) devices but face limitations in brittleness, solvent reliance, and fatigue resistance. These challenges are addressed by designing a solvent‐free, stretch‐oriented double‐network eutectogel integrating high‐molecular‐weight polyacrylamide (structural reinforcement) with a dynamic poly(acrylic acid)/choline chloride deep eutectic network (ionic conductivity). Synergistic effects between molecular chain entanglements and stretch‐induced alignment enhance mechanical robustness and energy dissipation, achieving tensile strength of 30.70 MPa, elongation of 703%, and record‐high toughness of 133.86 MJ m −3 (surpassing reported eutectogels). Crucially, the aligned microstructure preserves conductive pathways, enabling multimodal sensing with high sensitivity ( GF = 1.4 at 250% strain; TCR = 14.7% °C −1 ) and stability (>300 cycles, without abrupt signal drift). Solution‐based processing compatibility facilitates scalable fabrication of ultrathin coatings and printed patterns, demonstrated in functional HMI devices: a somatosensory glove (joint motion accuracy, latency <17 ms), and capacitive touchscreens (latency <34 ms), and temperature sensors (high thermal resolution). By resolving the strength‐flexibility paradox, this work provides a platform for wearable HMI systems requiring transparency, ultrahigh strength, intrinsic flexibility, and environmental adaptability.

This study investigates an alkali-resistant superabsorbent polymer (SAP-I) for cement-based materials, featuring a specialized "claw" distribution in concrete structures after pre-absorption water. To evaluate the performance changes in cement-based materials with SAPs, we compared laboratory-prepared alkali-resistant SAP (SAP-I) with commercially available ones (SAP-S). Firstly, the alkali-resistant SAP's adsorption capacity in tap water (185 g/g) is similar to commercial SAPs. However, its adsorption capacity in cement pores (21.63 g/g) far exceeds that of commercial SAPs (2.67 g/g), indicating a more significant internal curing effect. Secondly, the strength increase in cement-based materials with alkali-resistant SAP is significantly greater than with commercial SAPs. The alkali-resistant SAP maintains higher internal relative humidity in cement-based materials, promoting hydration and compensating for pore structure degradation. Thirdly, adding alkali-resistant SAP significantly improves the shrinkage performance of cementbased materials, with SAP-I having a mitigate shrinkage 2.11 times that of commercial SAPs. The combination of SAP particles with the cement forms an organic-inorganic interface, ensuring more uniform water release and significantly reducing autogenous shrinkage effects. In summary, compared to commercial SAPs, alkali-resistant SAPs show better compatibility with cement-based materials and greater potential for large-scale production, making them suitable for specific engineering applications.

Internal curing in high-performance cementitious materials (HPCM) is effectively achieved using superabsorbent polymers (SAP), which significantly mitigate autogenous shrinkage. However, the efficiency of internal curing is determined by factors such as the particle size, absorption capacity, and dosage of the SAP. Currently, the scientific community has not reached a consensus on the optimal SAP system for HPCM. This study examines the compatibility of SAP's absorption capacity, dosage, and particle size with HPCM through orthogonal experiments, focusing on their effects on mechanical properties and shrinkage performance. Additionally, the compatibility of SAPs with various chemical structures and the optimal SAP system was evaluated. Range and variance analysis results show that the optimal SAP system includes a dosage of 0.20 %, a particle size of 100-50 mu m, and an absorption capacity of 19.7 g/g. Compared to the control group (without SAP), the 28-day compressive strength decreased by only 0.77 %, while autogenous shrinkage reduced by 40.32 %. The optimal SAP system facilitated the hydration process of HPCM, reduced porosity, and increased the proportion of transition pore volume, significantly improving the pore structure. Furthermore, autogenous shrinkage decreased significantly with higher SAP dosage, smaller particle size, and greater absorption capacity. However, this also caused a substantial reduction in material strength and a marked increase in porosity, adversely affecting durability. The proposed optimal SAP system is compatible with superabsorbent polymers of various chemical structures. These findings offer valuable insights into SAP applications in HPCM, facilitating its broader adoption in practical engineering projects.

Understanding the in-situ polymerization mechanism of polymer monomers and its impact on the multi-scale mechanical properties of cementitious materials is critical for enhancing crack resistance and toughness. This study investigates the influence of varying acrylamide (AM) monomer contents on the multi-scale mechanical performance of composites prepared by in-situ polymerization of acrylamide monomers (IPAM). Macro-scale behavior was assessed through compressive and flexural tests, while nanoindentation and micro-scratch techniques evaluated micromechanical properties. Additionally, multi-scale homogenization models were used to correlate microstructure with macroscopic performance. Results show that incorporating an optimal AM dosage (similar to 2 wt%) forms a dense organic-inorganic interpenetrating network, improving flexural strength by 61.5 % and flexural energy by 140.7 % of cementitious materials. An increase in AM monomer doping decreases the indentation modulus and hardness of each microscopic phase in IPAM materials, primarily due to polymer absorption effects and the inherently low stiffness of the polymer. Moreover, polymer addition significantly alters the proportion and distribution of microphases, thereby influencing the toughness and crack resistance of IPAM materials. Multi-scale homogenization analysis reveals that changes in microphase proportions and their mechanical properties directly affect macroscopic elastic modulus and overall mechanical performance. These findings provide a theoretical foundation for modulating macroscopic properties through precise control of microstructural characteristics.

Superabsorbent polymers (SAPs) are widely studied as internal curing agents in high-performance concrete, but their adverse effects on pore structure remain a challenge. This study introduces an innovative cement-integrated SAP (CiSAP) by modifying the interface, using KH570-modified cement (KMC) as the functional core. By optimizing KMC content, the microstructure was improved, leading to enhanced performance. Structural characterization confirmed that KMC was successfully embedded into the polymer network. CiSAP30 reduced shrinkage by 61.4 % due to its excellent desorption efficiency. The 28-day strength retention of CiSAP in cement-based materials varied from 93.4 % to 99.6 %, compared to the reference group without CiSAP. MIP and fractal dimension analysis indicated that CiSAP refined the microstructure by reducing large capillary pores and filling macropores. The sustained water release from CiSAP, along with KMC hydration, promoted long-term densification and controlled autogenous shrinkage. This study provides a novel strategy for designing internal curing agents for high-performance cement-based materials.

Understanding the influence of alkali-resistant superabsorbent polymers (SAPs) on the performance of cementitious materials based on Portland Cement (PC) is crucial for optimizing their applications in construction. This study primarily focuses on the effects of varying SAP content on the multiple properties and hydration process of PC materials. The optimal dosage of alkali-resistant SAP (with an absorption capacity of 21.63 g/g in cement) for Portland cement with an effective water-to-cement ratio (w/c) eff = 0.20 is 0.20 m%. Under the condition of maintaining the same fluidity as the control group, strength decreased by only 2.1%, autogenous shrinkage was reduced by 36.7%, hydration of the cement-based material was enhanced, and the porosity of the matrix was reduced. As the SAP dosage increased (from 0.35 m% to 0.80 m%), the degree of cement hydration increased and autogenous shrinkage further decreased, but excessive SAP content led to an increase in residual pores within the matrix, reducing porosity and resulting in lower strength. Although SAP compensates for the negative effects on pore structure in the early stages of hydration, residual effects still contribute to reduced material strength. The study's findings reveal the interaction between SAP content and cementitious material performance, aiming to guide future optimization of SAP incorporation for enhanced material properties and sustainable construction practices.

The degradation and loss of structural integrity in concrete due to chloride ion-induced corrosion of steel reinforcement represent significant challenges that limit the service life of concrete structures. To combat this, cationic polymer (polydimethylaminoethyl methacrylate quaternary ammonium, PDEMAQA) grafted nano-silica (SiO2-g-PDEMAQA) was prepared by atom-transfer radical-polymerization (ATRP) reaction to enhance the chloride ion penetration resistance of cement. On one hand, cationic polymer provides the ability to facilitate the dispersion of nano-SiO2 within cement, thereby promoting cement hydration. On the other hand, the substantial presence of quaternary amine groups in cationic polymer enhances the capacity to effectively bind free chloride ions in cement. Consequently, the incorporation of a modest quantity of organic polymer-modified nano-silica could lead to marked improvements in both the resistance to chloride ion penetration and the compressive strength of cement. The experimental results demonstrate that cement doped with just 1.0 wt% SiO2-g-PDEMAQA could not only significantly improve early resistance to chloride ion penetration by 66.91 %, but also increase the compressive strength by 9.79 % after 28 days of curing. Benefiting from the synergistic effect of cationic polymer and nano-SiO2, SiO2-g-PDEMAQA exhibits highly efficient chloride ion penetration resistance and enhanced compressive strength. This work will develop a strategy of improving resistance to chloride corrosion in cement with high efficiency, and will contribute to the sustainable advancement of concrete technology.

This study investigates the impact of the chemical composition of superabsorbent polymers (SAPs) on their effectiveness in internal curing within high-performance cementitious materials. Although the use of commercial SAPs in cementitious systems has been widely researched, there is still no consensus on how different SAP structures influence material properties. For the first time, this research employs photoinitiated free radical polymerization technology to synthesize three structurally distinct SAPs: SAP with sulfonic acid groups (PAMPS), SAP with amide groups (PAM), and SAP with carboxyl groups (PAAs). The effects of these SAPs on the cement hydration process and microstructure were examined by analyzing their water absorption behavior in cement filtrate. The residual cation content on the SAP surface was evaluated using EDS, while XRD and TGA were used to study how SAP structure affects cement hydration products. Furthermore, the impact of these SAPs on the strength and autogenous shrinkage of the material was investigated. The results indicate that PAMPS, with its sulfonic acid groups, exhibited stable water absorption performance in the alkaline cement environment, promoting hydration reactions and increasing the formation of needle-shaped C-S-H. This stability contributed to mitigating the negative effects on mechanical properties. While the inclusion of SAPs generally reduced the strength of the cement matrix, PAMPS was the most effective in mitigating autogenous shrinkage, achieving a shrinkage mitigation efficiency of 86 %. These findings highlight the importance of SAP chemical structure in influencing cement hydration and material performance, offering insights for the development of effective internal curing agents to enhance high-performance concrete.

In this work, epoxy resin (EP)-based aqueous polyurethane (PU) anionic PU dispersion was synthesized by the prepolymer and self-emulsification method. The PU prepolymer was first synthesized to serve as seeds. Then, trimethylolpropane and A-type EP (E-51) were introduced into it, followed by neutralization and emulsification reactions, and, finally, it formed a crosslinking network structural waterborne PU emulsion. The effect of epoxy contents on the particle size, rheological properties, storage stability, thermal stability, mechanical properties, and hydrophilicity of the resulting PU films was systematically investigated. The results showed that the PU dispersions displayed excellent storage stability and crosslinking density, and the glass transition temperature of the composite films was increased. The properties of self-made epoxy-modified polyurethane emulsion and polyester-cotton fabric before and after finishing were tested. The wrinkle resistance, hydrophobicity, and strength of the finished polyester/cotton fabric are improved, and it exhibits better color fastness to washing and rubbing.

水性聚氨酯(WPU)是一种优异的绿色环保型高分子材料,广泛用于纺织材料、合成工业、建筑建造、生物医疗等领域,如纺织品涂层整理剂、水性木器涂料、皮革涂饰剂、固色剂、胶黏剂、沥青等,受广泛重视.目前WPU改性已成为多领域研究热点,是毒性溶剂型聚氨酯材料有前途的替代品之一.文章综述环氧树脂(EP)对WPU单组分改性和辅以其他适应性基材复合改性研究进展,并展望未来水性聚氨酯发展趋势.

In recent years, conductive polymer composites have been widely studied for their electrical conductivity and electromagnetic shielding effects due to their advantages of light weight, simple preparation methods, and structural design versatility. In this study, oxidized multi-walled carbon nanotubes/waterborne polyurethane composites (OCNT/WPU) were prepared by grafting oxidized carbon nanotubes onto polyurethane molecular chains through in situ polymerization, using environmentally friendly waterborne polyurethane as the polymer matrix. Then, the OCNT/WPU structure was broken by high shear force, and the loading of CNTs was increased by adsorption, and a new composite structure was designed (denoted by OCWPU). The structure and morphology of OCNT/WPU and OCWPU were characterized by FT-IR and SEM. The structure and morphology of OCWPU with different multi-walled carbon nanotube loadings (CNTs/OCWPU) were characterized by SEM, Raman. Finally, the electrical conductivity and the electromagnetic shielding properties of the composites were investigated. It was found that after application of high shear force, the structure of OCWPU was disrupted and the surface activity of the material increased. With the increase in CNTs content, CNTs formed a rosette structure in the polyurethane matrix and covered the surface, and its electromagnetic shielding effect in X-bond (8.2–12.4 Ghz) would be able to reach 23 dB at 5% CNTs/OCWPU and 66.5 dB at 50% CNTs/OCWPU to meet the commercial needs. With 50% CNTs/OCWPU, an electrical conductivity of 5.1 S/cm could be achieved. This work provides a novel idea for the structural design of conductive polymer composites, which can achieve greater performance with the same carbon nanotube content.

Despite the significant progress made in polymer/graphene nanocomposites, the development of high-performance polymer/graphene nanocomposites, combined with excellent mechanical and electromagnetic shielding properties, remains a priority and a challenge. The lanthanum doping large-size graphene oxide (La-LsG) was obtained via static oxidation and thermal treatment. The effects of static oxidation and lanthanum doping on the property and morphologies of graphene and composites were investigated. The physicochemical property of considerable graphene oxide (GO), large-size graphene oxide (LsGO), lanthanum-doped graphene oxide (La-GO), La-LsG was analyzed by transmission electron microscopy (TEM), scanning electron microscopy (SEM), Raman spectroscopy, and X-ray energy spectroscopy (EDS). SEM and EDS characterized the microstructure of the composite material, and the mechanical properties and electromagnetic shielding performance of the composite material were studied. La-GO and La-LsG exhibited good dispersion and structural integrity, as well as enhancing the strength of the composites. The La-LsG/poly (methyl methacrylate) (PMMA) composites exhibited excellent mechanical properties (is ca. 73.6 MPa) and electromagnetic shielding effectiveness (is ca. 28 dB) in X-band frequencies (8.2–12.4 GHz), which may be assumed to be a promising integrated material of structure and function.

The uniform dispersion of oxidized multi-wall carbon nanotubes (OCNT) in waterborne polyurethane (WPU) matrix was achieved by in-situ polymerization, endowing the OCNT/WPU composite film with enhanced tensile strength, thermal stability, and excellent elongation at break. The structure of multi-wall carbon nanotubes (CNT) and OCNT was characterized by TEM, XRD, XPS, and the structure and morphology of composites were characterized by particle size analysis, SEM and FT-IR. Compared with pure WPU and OCNT/WPU composite, the breaking strength and the thermal degradation temperatures of 20 % weight loss of the OCNT/WPU com-posite were increased by 175 % and 353 degrees C, respectively. The oxygen-containing functional groups effectively improved the surface active of OCNT, making it easier for OCNT to react with polyurethane prepolymers. After addition of only 1 % OCNT, the tensile strength approaches 77 MPa while the elongation at break remains at 277 %. In addition to having outstanding chemical and mechanical properties, OCNT have a better dispersibility rate than multiwalled carbon nanotubes, which means that they will have a broader application range.