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Highlights: [•] Catalysts of Mn-Ce-M/TiO2 (M=Fe, Ni) prepared by co-precipitation method for low temperature selective catalytic reduction (SCR). [•] Using carbamide solution, ammonia and hydrogen peroxide as precipitation agents, showed good activity in low temperature and resistance performance of K+ cation (K/Mn=0.5). [•] Poisoning mechanism occurs via chemical bonding of the K+ cation to the M OH sites, the so-called Brønsted acid sites. [ABSTRACT FROM AUTHOR]

• The construction of inherent reactive XPSF surface by ultraviolet-zone. • The fabrication of covalently bonded XPSF/mortar interfaces. • The thorough investigation of the reactions between APTES and XPSF surface. The inert surface of extruded polystyrene foams (XPSF) was activated by ultraviolet-ozone (UVO) for the first time to improve the interfacial compatibility with mortar. From the structural analysis (X-ray photoelectron spectroscopic (XPS) and contact angle (CA)), it was suggested that a 10 min UVO exposure was efficient enough to introduce oxygen-contained elements (such as carboxyl groups) upon the obtained UVO-XPSF surface, leading to the increased bonding strength (BS) from 0.058 MPa of neat XPSF/mortar composites to 0.088 MPa. Then, 3-aminopropyl triethoxysilane (APTES) was selected as the promoter to further enhance the BS value of XPSF/mortar composites. The presence of the silane was confirmed by CA, Fourier transform infrared-attenuated total reflection (FTIR-ATR) and XPS. By optimizing the reaction conditions (activation and reaction time: 7 and 3 min, concentration of APTES: 2% and pH value of the silane solution: 10), a maximum BS of 0.168 MPa could be obtained. Through the mechanism analysis, it was demonstrated that APTES acted as a chemical bridge that covalently jointed XPSF by the formation of amide peptide and inorganic mortar by the condensation of silanols. [ABSTRACT FROM AUTHOR]

Abstract  β-1,3-Glucanases are a group of pathogenesis-related proteins that have been reported to be involved in plant defense against pathogens in many other plant-pathogen systems. However, it was not clear if these genes play similar role in wheat (Triticum aestivum L.) against Puccinia striiformis f. sp. tritici (Pst), the stripe rust pathogen. To investigate the role of β-1,3-glucanase (EC 3.2.1.39) in the resistance response of wheat (cv. Suwon 11) to stripe rust, a wheat β-1,3-glucanase gene induced by Pst, designated as TaGlu, was cloned and characterized. TaGlu was predicted to encode a basic protein of 334 amino acids. Quantitative real-time PCR analyses revealed that the transcription of TaGlu was induced during both compatible and incompatible interactions with Pst, but the transcription level was much higher in the incompatible interaction than that in the compatible interaction. TaGlu also showed noticeable induction of gene expression in young green leaf tissues treated with salicylic acid, methyl jasmonate or ethylene. Immunogold labeling assays showed that the enzyme were localized mainly in the host cell wall and over the extrahaustorial matrix, and the labeling densities were found significantly higher in the incompatible interaction than those in the compatible interaction. [ABSTRACT FROM AUTHOR]

The chemical structures of four types of superplasticizers (SPs) and their adsorptive behaviors on β-C2S were investigated. The adsorption properties of SPs on β-C2S were measured and the relationship between the adsorption quantity and the specific surface of β-C2S was analyzed. The experimental results show that the adsorption quantity increases with the surface area increase of β-C2S, but the adsorption quantity per surface area is similar, which means that the main adsorbent is β-C2S itself. Polycarboxylic ester (PCE) showed the highest adsorption amount on β-C2S, followed by β-naphthalene sulfonates (NSF) and formaldehyde-acetone condensates sulfonates (FAS), amino sulphonate (AS) showed the least adsorption amount on β-C2S. PCE affected the surface potential of β-C2S particles in water differently in comparison with other types of SPs. The adsorption capacity of SPs on β-C2S is determined by factors such as molecular structure, functional groups and molecular weight of SPs. [ABSTRACT FROM AUTHOR]

Pb SA -Cu/PC with a three-dimensional structure was demonstrated as an efficient CO 2 reduction catalyst to formate. Pb inhibited the formation of COOH*, reduced the energy barrier of rate determining step in the formate formation process, and achieved 97% high formate selectivity. [Display omitted] • Pb SA100 -Cu/CP catalyst is developed by an economical and low-energy method. • The FE formate is 97 % with a partial current density of 27.9 mA cm−2 at − 0.9 V. • The catalyst exhibits ultra-long stability for more than 60 h. • The synergistic action of Pb SA and Cu atoms lowers the RDS for CO 2 RR to fromate. • Single-atom Pb induces Cu charge redistribution and inhibits the formation of COOH*. Exploring highly selective and stable electrocatalysts is of great significance for the electrochemical conversion of CO 2 into fuel. Herein, a three-dimensional (3D) nanostructure catalyst was developed by doping Pb single-atom (Pb SA) in-situ on carbon paper (Pb SA100 -Cu/CP) through a low-energy and economical method. The designed catalyst exhibited abundant active sites and was beneficial to CO 2 adsorption, activation, and subsequent conversion to fuel. Interestingly, Pb SA100 -Cu/CP showed a prominent Faraday efficiency (FE) of 97 % at –0.9 V versus reversible hydrogen electrode (vs. RHE) and a high partial current density of 27.9 mA·cm−2 for formate. Also, the catalyst remained significantly stable for 60 h during the durability test. The reaction mechanism was investigated by density functional theory (DFT), demonstrating that the doping Pb SA induced the electrons redistribution, promoted the formate generation, reduced the rate-determining step (RDS) energy barrier, and inhibited the hydrogen evolution reaction. The study aims to provide a new strategy for developing of single-atom catalysts with high selectivity and stability, which will help reduce environmental pressure and alleviate energy problems. [ABSTRACT FROM AUTHOR]

In the cement industry, SO2 and NOx are generally removed separately. There are many problems, such as large area, high investment cost, secondary pollution and so on. Desulfurization and denitrification technology have become a frontier research direction in the field of air pollution control. In this paper, rice husk ash and carbide slag were compounded and modified to prepare modified rice husk ash-carbide slag composite absorbent, and its desulfurization and denitrification performance and mechanism were studied. The results showed that the NO conversion and SO2 conversion of the modified rice husk ash-carbide slag composite absorbent increased by 44% and 2%, respectively, at 700 °C. Fibrous calcium silicate and calcium silicoaluminate hydrates were formed during the hydration process, which made the specific surface area of the absorbent larger and provided more reactive sites. The hydration process increases the content of oxygen-containing functional groups, decreases the hydroxyl/ether C–O functional groups, and increases the content of carboxyl–COO functional groups are conducive to the denitrification reaction. [ABSTRACT FROM AUTHOR]

Nitrogen oxide (NOx) emissions have attracted much attention for increasing concern on the quality of the atmospheric environment. In view of NO decomposition in the cement production process, the preparation of Cu-Al/SiO2 porous material and its effect on NO decomposition were studied, and the denitrification mechanism was proposed in this paper. The NO decomposition performance of the Cu-Al/SiO2 porous material was tested via the experimental setup and infrared spectrometer and micro gas chromatography (GC). The result shows that the Cu-Al/SiO2 porous material with the template of cetyltrimethylammonium bromide (CTAB) had a better NO decomposition rate than materials with other templates when the temperature was above 500 °C, and NO decomposition rate could approach 100% at high temperatures above 750 °C. Structure analysis indicates that the prepared Cu-Al/SiO2 material structure was a mesoporous structure. The X-Ray Diffraction (XRD) and Ultraviolet–visible spectrophotometry (UV–Vis) results of the denitrification product show that the Cu-Al/SiO2 material mainly decomposed to Cu2O and Si2O, and the CuO decomposed to Cu2O and O2 at high temperature. The Cu(I)O was considered as the active phase. The redox process between Cu(II)O and Cu(I)O was thought to be the denitrification mechanism of the Cu-Al/SiO2 porous material. [ABSTRACT FROM AUTHOR]

Tertiary alkanolamines play an essential role in the hydration of cement-based materials as one of the main components of cement grinding aids and concrete admixtures. Although the field has been well-studied, the significant effects of slight variations in alkanolamine type and dosage make it imperative for researchers to fully understand alkanolamines before using them. Therefore, it is necessary to understand in detail the mechanism of different alkanolamines affecting the hydration of cement-based materials and their effects on setting and hardening. Based on the synthesis and chemical characteristics of alkanolamines, the complexation between alkanolamine and metal ions is discussed in this paper. The influence of alkanolamines on hydration of cement-based materials and the role of complexation in hydration are studied. Various properties of cement-based materials in the presence of alkanolamines are rigorously reviewed. The synergistic effects of alkanolamine and other admixtures are also considered in this review. The research findings prove that the complexation of alkanolamines plays an essential role in hydration and further interferes the microstructure and properties of the cement-based materials. Variations in the molecular structure and dosage of alkanolamines can lead to significant differences in hydration. The modification of alkanolamines at the molecular level and their use in combination with other admixtures are the future research directions. The working mechanism of alkanolamines in the hydration process of cement-based materials still needs to be further explored. • Complexation of alkanolamines significantly affects cement hydration. • Different alkanolamines have different effects on mineral phase hydration. • Alkanolamines significantly affect the morphology of C-S-H gels and Ca(OH) 2. • The right dosage of alkanolamine could improve compressive strength. • TEA has a significant effect on setting time. [ABSTRACT FROM AUTHOR]

Steel slag (SS) as a supplementary cementitious material has low cementitious activity. Diethanol-isopropanolamine (DEIPA) is an organic admixture that can enhance the cementitious activity of cementitious materials. This work aimed to investigate the hydration characteristics of SS under the complexing of DEIPA. The hydration process of SS, the complexation of DEIPA with metal ions, and the dissolution process of C 3 A and C 3 S in the presence of DEIPA were systematically investigated. The results showed that DEIPA enhanced the hydration of aluminate (C 3 A and C 12 A 7), ferrate (C 2 F) and silicate phases (C 3 S and C 2 S), which formed a large amount of monocarboaluminate, paraalumohydrocalcite and C–S–H gels. In the early stages of hydration, the hydration products were mainly C–S–H gels, monocarboaluminate and paraalumohydrocalcite, and in the later stages of hydration, the hydration products were mainly C–S–H gels, paraalumohydrocalcite. The monocarboaluminate may be transformed to paraalumohydrocalcite at a later stage. This hydration-promoting effect was related to the complexation of DEIPA. DEIPA facilitated the dissolution of mineral phases and the precipitation of complexed metal ions by complexing with metal ions. The stronger complexation of Al3+ by DEIPA made it more solubilizing for C 3 A. As a result, more aluminum-containing hydration products were formed. The weaker complexation of Ca2+ by DEIPA made it a weaker solubilizing for C 3 S, which also led to a weaker promotion of silicate hydration by DEIPA. The solubilization of DEIPA to minerals enhanced the cementitious activity of SS, which ultimately led to the increase in the compressive strength of the hardened SS paste at each age. [ABSTRACT FROM AUTHOR]

Ferroaluminate cement is widely used in marine engineering applications owing to the remarkable durability and strength of its main hydrate, Al(Fe)–ettringite. The structure and performance of Al(Fe)–ettringite still require extensive exploration. An Al(Fe)–ettringite molecular model containing different Fe contents (0%, 25%, 50%, and 75%) was developed via Materials Studio. Radial distribution functions, time-correlated functions, and mean square displacement were used to analyze the structure of Al(Fe)–ettringite, after which Al(Fe)– ettringite was prepared using a coprecipitation method. The hydration of Al(Fe)–ye'elimite, the nanoindentation testing, and compressive strength of four ettringite types were assessed to facilitate a comparison with the simulation results. Increasing the Fe content resulted in increased lattice size and density. Fe atoms mainly reacted with Ohs atoms to form Fe–Ohs bonds, resulting in an increased Fe–Ohs bond length, with the Fe atom density resulting in volume expansion and increased density in Al(Fe)–ettringite. At 25% Fe content, the number of Hw–Ow hydrogen bonds in Al(Fe)–ettringite was 1166.14, the MSD value was 1.53 Å2, and the water molecules diffused the fastest. The improved macromechanical properties obtained by adding Fe atoms demonstrate that Fe atom substitution can enhance the ettringite structure. The experimental results validated the simulation results. [ABSTRACT FROM AUTHOR]

In this paper, the strength development of a pure steel slag (SS) system with various concentrations of N,N,N′,N′-Tetrakis-(2-hydroxyethyl) ethylenediamine (THEED) was investigated. The hydration kinetics, pore structure and microstructure of SS pastes with and without THEED were characterized to underscore the working mechanism of THEED. Results show that THEED additions significantly increase the 3, 7 and 28 days compressive strength of hardened SS pastes. The enhancement effect increases with the dosage of THEED. At a concentration of 2000 ppm, THEED increased the compressive strength by 733%, 665%, and 545% at 3, 7 and 28 days, respectively. It is confirmed that THEED additions improve the hydration degree of SS by accelerating hydration of the aluminum phase (C3A, PDF-38-1429; C12A7, PDF-48-1882) and C2F,(PDF 38-0408) to generate Mc (PDF-41-0219) and Pa (PDF-30-0222) in the presence of CaCO3. Also, the hydration degree of silicates is increased by THEED. In this way, THEED additions refine the pore structure of hardened SS paste by increasing the pore volume with a diameter below 300 nm to achieve enhancement. The chelating effect of THEED results in promoting dissolution of SS, which provides the driving force for accelerating SS hydration. [ABSTRACT FROM AUTHOR]

NOx emission from the cement industry have received much attention. In order to reduce the NOx emission in cement kilns, nickel slag was used to prepare the non-ammonia denitrification material, and a denitrification mechanism was proposed in this study. The results showed that the denitrification material prepared at pH 7 exhibited the best denitrification performance. At low temperature, the highest denitrification performance was achieved between 200 and 300 °C with a NO decomposition rate of approximately 40%. Then, the NO decomposition rate increased as the temperature increased, reaching over 95% above 700 °C. The physicochemical characteristics showed that the material had the highest specific surface area and the highest relative Fe content, which benefited the denitrification performance. The divalent iron of the denitrification material was considered the active site for the reaction, and trivalent iron was not conducive to denitrification performance at a low temperature range. After the denitrification reaction, the Fe3+/Fe2+ increased from 0.89 to 1.31. The proposed denitrification mechanism was the redox process between divalent iron and trivalent iron. This study not only recycles industrial waste to reduce solid waste pollution but also efficiently removes nitrogen oxides from cement kilns without ammonia. [ABSTRACT FROM AUTHOR]

The combined utilization of mineral accelerators and nano-seeding materials is a novel method to promote the early strength of cement-based materials. In this paper, the effects of nano-C-S-H seed (NCS) on the early compressive strength of the Portland cement (PC)– calcium sulfoaluminate cement (CSA) binder were investigated. The results showed that NCS and CSA synergistically contributed to the early strength of PC. In detail, a 326.3% increase in the 10 h compressive strength of PC paste was obtained through the addition of NCS (2 wt%) and CSA (5%) in common. This was higher than the sum of the increases observed with the single additions of CSA (157.9%) or NCS (87.6%), with the same above dosage, in PC. Meanwhile, the early strength enhancement effects of NCS and CSA, when used together in PC, lasted longer than the effects of either used alone. Moreover, the synergetic effect mechanism was analyzed by isothermal calorimeter, QXRD, TGA, MIP, and SEM techniques. The calorimetry, XRD, and TGA results demonstrated that the synergistic mechanism was associated with the synergistic promotion effects of CSA and NCS on the hydrates. The fast hydration of CSA produced large amounts of ettringite and also consumed partial free water to promote the performance of the seeding effect of NCS which, simultaneously, further accelerated the precipitation of C-S-H gel and CH. The high alkie environment was also beneficial for the continuous generation of ettringite. In addition, the results of MIP and SEM measurements showed that the micro-filling effect of NCS significantly optimized the pore structure of a PC-CSA blend-hardened paste. Thus, the synergistic strength enhancement effects of CSA and NCS on PC were attributed to the matching of the promotion of hydration generation and the optimization of pore structures in hardening cement paste. The results of this article provide a new approach to achieving the rapid development of the early strength of cementitious materials, with potential applications in precast concrete and low-temperature construction. [ABSTRACT FROM AUTHOR]

Concrete cracking has a negative impact on the durability of the structure. Pre-implanting microcapsules containing healing agents into the concrete are expected to induce the cracks to self-heal. However, the self-healing effect can potentially be influenced by several environmental conditions, thus limiting its applications. To address these challenges, we developed a new type of water-absorbing microcapsules, using calcium alginate hydrogel as the wall material and an adhesive epoxy polymer as the core material, to improve the self-healing adaptability in complex and changing environments. We explored the healing properties and mechanism of cementitious materials containing microcapsules under various environmental conditions. The experimental results showed that the water-absorbent microcapsules exhibit multiple self-healing effects under different external conditions: (1) in an anhydrous environment, fissures prompted the activation of microcapsules, and the epoxy polymer flowed out to seal the cracks. (2) When exposed to water, the microcapsules inflated to form a seal around the fissures. (3) The microcapsules facilitated the autogenous healing of cracks in the cementitious material when wet and dry conditions were alternated. The three self-healing mechanisms worked synergistically and contributed to the effective restoration of the impermeability and strength of concrete under different environments. Particularly, the recovery of compressive strength and impermeability exceeded 100% when the microcapsule content was 4% and the pre-pressure was 40% of fmax. [ABSTRACT FROM AUTHOR]

Ca(OH)2, a widely available and low-cost calcium-based desulfurizer, needs further improvement in calcium utilization in flue gas desulfurization. In this experiment, Ca(OH)2 crystals with different morphologies were prepared by doping impurity ions including SO42− and SiO32− by precipitation method, which played directing role in the process of crystal growth. The prepared Ca(OH)2 crystals were applied to cement kiln flue gas desulfurization environment to investigate the effect of crystal morphology on flue gas desulfurization. The observed results illustrated that Ca(OH)2 prepared by SO42− as impurity ion in hexagonal plate shape presents the best desulfurization performance with desulfurization efficiency up to 93%. The structural characterization of Ca(OH)2 crystals by XRD and SEM, and the investigation of the reasons for desulfurization by BET, EDS, and XPS showed that the hexagonal plate-shaped Ca(OH)2 crystals increased the specific surface area and had the highest elemental sulfur content of 5.04% on the (100) crystal plane, and the high surface energy on the (100) plane led to the high reactivity. This confirms the guiding significance of hexagonal plate-like morphology for improving the desulfurization performance of Ca(OH)2. [ABSTRACT FROM AUTHOR]

Reducing or eliminating cracks caused by shrinkage of cementitious materials remains a daunting challenge for construction engineers. Drying shrinkage and autogenous shrinkage are the main shrinkage types in the service process of cement-based materials, which have a great impact on engineering applications. If cracks in concrete generate by drying or autogenous shrinkage, the mechanical properties, water resistance and durability of concrete will be also affected. It is an effective method to use chemical admixtures to inhibit the shrinkage of cement-based materials. Polycarboxylate plasticizer (PCE) is an important chemical admixture in cement-based materials and is widely used in practical engineering. It can bring great value by reducing the shrinkage effect through molecular design. Through our innovative design, a series of shrinkage-reducing polycarboxylate superplasticizers (SRPs) were synthesized, their molecular structures were confirmed by Fourier transform infrared spectroscopy (FTIR) and their molecular properties were determined by gel permeation chromatography (GPC). Furthermore, the shrinkage performances at different ages of the mortars containing the synthesized SRPs with different structures were systematically evaluated. The results showed that compared with the blank sample, the dry shrinkage rate and free shrinkage rate of the mortars containing SRP decreased by over 20% and 15%, respectively. Additionally, the shrinkage rates of the mortars containing SRP were significantly lower than that of the mortar containing conventional PCE, and moreover, the water-reducing performance was improved compared to conventional PCE. Based on the experimental results of surface tension and evaporation rate of different SRP solutions, the mechanism of the shrinkage-reducing effect was probed, as expected to provide guidance for the design and development of new shrinkage-reducing admixtures. [ABSTRACT FROM AUTHOR]

Polycarboxylate ether (PCE) superplasticizers are widely used in concrete, but in some cases, PCE aggravates the occurrence of cracks. This study evaluates the shrinkage reduction and plasticizing properties of a newly synthesized shrink-reducing polycarboxylate polymer (KH-SRPC) modified with ester and silane groups. When the KH-SRPC was implemented at a dosage of 0.3% by weight of cement, the adsorption capacity on the surface of the cement particles and the spreading diameter of the cement improved with respect to traditional PCE. Furthermore, the autogenous shrinkage and drying shrinkage of the mortar containing KH-SRPC were also investigated. When the KH-SRPC content was 0.2% of the weight of the cementitious material, the autogenous shrinkage of the KH-SRPC mortars at 3 and 7 days was reduced by 72.6% and 43.5%, respectively. The drying shrinkage of KH-SRPC mortars decreased by 38.3% at 3 days, 39.0% at 7 days, 39.1% at 14 days, and 35.7% at 28 days. It was found that KH-SRPC changed the pore structure of the solidified mortar, reduced the surface tension of the pore solution, and slowed down the rate of hydration, thereby reducing the total shrinkage of the mortar system. [ABSTRACT FROM AUTHOR]

The issue of slow early setting and strength development is a common problem faced by natural hydraulic lime (NHL) in both historic building restoration projects and modern construction. This study aims to reveal the phase composition and microstructure of natural hydraulic lime-based materials modified by metakaolin and its effect by natural carbonation. The results demonstrate that metakaolin could promote the setting times of NHL and generally exhibit a significant enhancement effect on the mechanical strength. Additionally, the drying shrinkage of NHL mortar can be effectively reduced by adding 10% metakaolin. In terms of hydration products, C4AĈH11 and C-S-H are identified as primary products during the early stages for M-NHL mortars, along with other hydration products such as C-A-(S)-H being formed later on. At longer ages, the carbonation reactions occur primarily with C-S-H and C-A-(S)-H phases, while decomposition or transformation into other phases is more likely for C4AĈH11. Interestingly, when M-NHL mortars with 10% metakaolin, it not only promotes early hydration but also enhances long-term carbonation processes. The carbon dioxide uptake effect (~ 20% mass %) is also found significant, and the low carbon effect in the whole life cycle means that M-NHL is environmental friendly materials. The pozzolanic effect induced by metakaolin reduces macropores and refines pore size within M-NHL system, which helps maintain high pore connectivity coefficient as well as effective porosity and more effective pathways conducive to inward transportation of CO2 gas, thereby promoting the carbonation process. [ABSTRACT FROM AUTHOR]

Although the side chain ionizability (the adsorption group density and adsorption space are changed) of polycarboxylate superplasticizer (PCE) serve as the key structural parameter in affecting the cement hydration, its effect on cement hydration is unclear. Based on PCE with nonionizable side chain (NSC-PCE) and the PCE with ionizable side chain (ISC-PCE), the influence of the side chain ionizability of PCE on the hydration behavior of cement was studied. Compared with NSC-PCE, ISC-PCE has a stronger ability to change the migration of water and ions, thus delaying the crystal nucleation and growth of cement hydration (better morphology and distribution, the crystal size was reduced by more than 20 %), increasing the crystal growth index (tendency toward spherical growth), prolonging the phase boundary reaction (reduce micro-cracks), which was conducive to the formation of more uniform and dense crystals (good strength, ISC-PCE: 50.0 MPa > NSC-PCE: 49.2 MPa > Blank: 48.7 MPa). These findings provide the design basis and theoretical guidance for the innovative development of PCE. [Display omitted] • ISC-PCE decreases the hydration rate and hydration degree of cement. • The effect of PCE on the hydration process was studied by the hydration kinetics model. • ISC-PCE has a stronger ability to change the migration of water and ions. • Proposes working mechanism in viewpoints of dissolution-precipitation equilibrium. • Tailoring the side chain ionizability was a new strategy to tune the performance of PCE. [ABSTRACT FROM AUTHOR]

• Effective modification of extruded polystyrene foam (XPSF) by the ultraviolet-ozone. • Amphipathic silane coupling agents as the adhesion promoters between XPSF and mortar. • A significant improvement on the interfacial strength of XPSF/mortar. • The chemical linkages can be induced by different kinds of silanes. The inert surface of extruded polystyrene foam (XPSF) was activated by the ultraviolet-ozone (UVO) irradiation, followed by the surface coupling reactions with γ-mercaptopropyl trimethoxysilane (MPTMS) and vinyl triethylsilane (VTEO) to improve the interfacial affinity between the organic XPSF and inorganic mortar. The reaction conditions (including reaction time, concentration and pH of the silanes) were thoroughly investigated in order to reach the maximum bonding strength (BS) of XPSF/mortar composites. It was suggested that the presence of MPTMS could increase the BS value from 0.04 MPa to 0.178 MPa (reaction time: 10 min, concentration of MPTMS: 2% and pH value of the silane solution: 4). For VTEO, the maximum BS value reached to 0.140 MPa (activation and reaction time: 7 and 3 min, concentration of VTEO: 5% and pH value of the silane solution: 7). According to the mechanism analysis, the thiol groups in MPTMS have the strongest reactivity with activated XPSF surface after UVO exposure, leading to the maximized interfacial strength between the organic insulation materials and inorganic mortar. [ABSTRACT FROM AUTHOR]

[Display omitted] • EG@PDMS6-t foams have realized effective immiscible oil–water separation by selective adsorption. • EG@PDMS6-t foams can adsorb kitchen waste oil. • P20s-S0.2-EG@PDMS6-t filters show excellent oil–water gravity-driven separation performance. • The foams exhibit impressive elasticity, reusability, and resistance to chemical corrosion. 3D porous foams for oil–water separation via selective adsorption were obtained by incorporating expanded graphite (EG) granules into polydimethylsiloxane (PDMS) foams. The EG@PDMS6-t foam prepared with a PDMS:EG and NaCl:PDMS mass ratio of 6:1 and 8:1, respectively, possesses a high porosity of 80.3%, a water contact angle of 127.7°, and an oil contact angle close to 0°. The foam exhibits an impressive adsorption capacity towards light oil (hexane,6.28 g/g), heavy oil (trichloromethane, 13.33 g/g), and kitchen waste oil (4.51 g/g), being able to separate 100% of oils from an immiscible oil–water mixture and 39.0% of camellia oil and 45.3% of kitchen waste oil from oil-in-water emulsions via selective adsorption. The foams possess excellent elasticity and desirable reusability in oil–water separation and exhibit outstanding resistance to acidic and alkaline environments. EG accounts for 96.5% of the EG@PDMS6-t foam's volume. SiO 2 @PDMS hydrophobic layer was constructed on the top of EG@PDMS6-t foams by a spraying technique to tailor-make 3D filters for oil–water gravity-driven separation. The P20s-S0.2-EG@PDMS6-t filter shows an excellent immiscible trichloromethane-water gravity-driven separation, with a trichloromethane permeate flux of 11,024 L/m2h, a water rejection time of 60 s, and a separation efficiency of 99.7%. The filters are highly robust to chemical corrosion and tape-peeling. [ABSTRACT FROM AUTHOR]

The application of cement-based materials in engineering requires the understanding of their characteristics and subsequent deformation and fracture process of C–S–H gel in service. In this work, three types of amine molecules including tetraethylenepentamine (TEPA), polyacrylamide (PAM), and triethanolamine (TEA) were intercalated into C–S–H gel in an unsaturated status successfully. Systematical analysis was performed on the structures and properties for both C–S–H gel and corresponding amine molecules/C–S–H gel. It was found that the unsaturated intercalation of amine molecules into C–S–H gel plays a key role in the geometry and therein density of nanocomposites. Subsequently, radial distribution function (RDF), time-correlated function (TCF), and mean square displacement (MSD) were applied to characterize the structure and dynamic information of the as-generated nanocomposites, demonstrating the occurrence of interaction between amine molecules with Ca–Si layer and acceleration of water diffusion by unsaturated intercalation of amine molecules into the interlayer region in C–S–H gel. Finally, the deformation and fracture process of C–S–H gel and amine molecules/C–S–H gel under uniaxial tensile loads were given by molecular dynamics simulation. It was indicated that the tangent modulus of nanocomposites demonstrates a strain-softening nature, indicating a visco-elastic behavior. The breakage of Ca–O bonds and hydrogen bonds dominates the fracture of C–S–H gel. Weak interaction for TEPA/C–S–H gel or TEA/C–S–H gel leads to a decreased tensile strength. Local stress concentration in other interlayer region governs the deformation and fracture process in spite of the formation of strong interaction between double bonded polar oxygen atoms in PAM molecules and Ca atoms in C–S–H gel. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel PCE (ISC-PCE) with ionic side chains was elaborately designed and synthesized. • Good plasticizing and retention capacities were shown for wide potential applications. • Larger R h and more adsorption sites led to a gentle and continuous adsorption mode. • Introducing ionic groups into PCE side chains can greatly thicken the adsorbed layer. • Particularly designed "brush" conformation helped to improve the dispersion stability. A novel dispersant with ionic side chains (ISC-PCE) for cement slurries was elaborately designed and prepared by a simple two-step method and its molecular structure was proved. The performance test results showed that the cement paste containing ISC-PCE exhibited stronger fluidity retention (about 79.6 % after 3 h), longer free settling time (more than 3 h) and fewer flocculating structures, which presented significant dispersing stability. Furthermore, the working mechanism of ISC-PCE to cement particles was also probed via molecular conformation, adsorption, complexation ability, zeta potential and adsorbed layer measurements. It is interesting that the introduction of ionic side chains into conventional dispersant-polycarboxylate superplasticizer (PCE) molecules can achieve gentle and continuous adsorption and increase the adsorbed layer thickness (increased by 103.1 % compared to conventional PCE). The aim of this study is to offer a promising pathway to synthesize a novel PCE endowing outstanding workability stability and great rheological improvements to cement pastes by innovative molecular design. This PCE with ionic side chains has enormous promises as an effective substitute to conventional PCE with nonionic side chains, particularly in the cement paste systems with strict requirements on slump retention. [ABSTRACT FROM AUTHOR]

This study fabricated a kind of novel phase change microcapsules with a metal-polymer hybrid capsule shell for applying in gypsum materials to reduce building energy consumption. The microstructure, composition and thermal characteristics of the microcapsules were investigated by using techniques such as the scanning electron microscope, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and differential scanning calorimetry. Their impact on the thermal regulation characteristics of gypsum composite materials was also analyzed through the heating plate test and simulated room experiment. Results show the microcapsules with inner organic polymer and outer copper layer were successfully fabricated. And they exhibited a phase change temperature between 22.3 ℃ and 23.3 ℃ and latent heat between 82.2 J/g to 139.5 J/g. Meanwhile, the thermal inertia and thermal storage capacity of gypsum composites were enhanced by incorporating the final microcapsules. After heated for 40 min, the gypsum composite board with MPCM-Cu shows the ability to reduce the room temperature fluctuation. Furthermore, the thermal performance of MPCM-Cu remains stable after 250 thermal cycles. These results indicate that final microcapsules exhibit the potential for building energy conservation. [Display omitted] • MPCM-Cu with binary esters as core and polyurea-copper hybrid shell are synthesised. • The phase change temperature of MPCM-Cu is within the human comfort temperature range. • Higher MPCM-Cu content results in lower temperature fluctuation of gypsum composite. [ABSTRACT FROM AUTHOR]

In this study, the impacts of CO 2 -absorbed triethanolamine solutions (TEA-CO 2) on the mechanical property, phase composition and micro-structure of cement mortars were investigated. The results showed that TEA-CO 2 addition increased the 1d, 3d, and 28d compressive strength by 47%, 19%, and 4%, respectively, which suggests a synergistic effect of triethanolamine and absorbed CO 2 on strength development of cement mortars. The enhancement is due to TEA-CO 2 accelerates hydration of aluminate and silicate phases in early age. TEA-CO 2 facilitated CaCO 3 formation to increase cement hydration degree and modify the pore structures. However, the hydration of silicate phases was delayed slightly by TEA-CO 2 at 28d. The above results provide theoretical support for further utilization of CO 2 in cementitious materials. • Effect of TEA-CO 2 on strength development of mortars was investigated. • TEA-CO 2 addition increases flexural and compressive strength of mortars. • TEA-CO 2 accelerates the hydration of aluminate phase and silicate phase at early age. • A synergism of cement hydration and carbonation in the presence of TEA-CO 2 was proposed. [ABSTRACT FROM AUTHOR]

UV curable organic-inorganic hybrid (OIH) coatings were used to modify the extruded polystyrene foam (XPSF) surfaces to increase the bonding strengthen (BS) of XPSF/mortar composite (XMC). OIH coatings contained polyurethane acrylate, hexanediol and nanoparticles with different dimensions. With the addition of nano-SiO 2 and halloysite nanotubes, the BS-D (BS in dry state) & BS-W-2H/7D (BS in wet state after 2-hour/7-day drying) values for modified XMC were increased from 0.050 & 0.039/0.047 MPa to 0.245 & 0.196/0.356 and 0.312 & 0.233/0.323 MPa. The chemical bonding between SiO 2 /-COOH from UV coating and hydration products in mortar improved the bonding state. [Display omitted] • Modification of XPSF surface by UV curable organic-inorganic hybrid coating. • The fabrication of chemical bonding for XPSF/mortar interfaces. • The investigation of the reactions between mortar and modified XPSF surface. [ABSTRACT FROM AUTHOR]

• The hydration of glass is heterogeneous due to phase-separation structure; • The heterogeneous hydration of glass impact the formation of calcium hydroxide; • The hydration rate advantage of calcium-rich and silicon-rich phase can be reversed; • The heterogeneous hydration is suitable for thermodynamic simulation of cement paste; Supplementary cementitious materials (SCMs) affect the hydration process and long-term properties of cementitious systems. Since a large percentage of SCMs belong to alkaline-earth aluminosilicate glasses that possess a phase-separated structure, further research into their hydration characteristics is essential. This study investigated the effects of the hydration characteristics of synthetic glasses with various phase-separated structure on the phase evolution of cementitious systems by combining simulations with experiments. The results showed that with the increasing degree of phase separation, the hydration of synthetic glass transitions from homogeneous to heterogeneous hydration. The phase evolution of hardened paste, particularly for calcium hydroxide, is influenced by the difference in hydration rates among each separated glassy phase. Compared to homogeneous hydration, the rapid hydration of the Ca-rich phase reduced the consumption of calcium hydroxide, while the rapid hydration of the Si-rich phase accelerated calcium hydroxide consumption. For glasses exhibiting phase separation characteristics, the consistency between thermodynamic simulations employing a heterogeneous hydration model and experimental results exhibits a notable enhancement. [ABSTRACT FROM AUTHOR]

In this paper, star -like polycarboxylate superplasticizer (SPCE) and comb -like polycarboxylate superplasticizer (CPCE) were prepared via atom transfer radical polymerization (ATRP) to study the mechanism of the effectiveness enhancement resulting from this transformation of topological structure. It was found that SPCE molecules acted higher adsorption amount and more Ca2+ complexes, and formed a lower and more compact adsorbed layer and larger surface coverage with a flat conformation on cement surface, depending on more anchored points per unit volume. Through this mechanism, cement particles adsorbed by SPCE showed stronger dispersible capability and colloidal interaction forces (the steric force was dominant), resulting in lower yield stress and plastic viscosity of the cement paste containing SPCE which behaved as an ideal Bingham fluid. The aim of this study is to clarify the mechanistic correlation between topological structure evolution and effectiveness promotion for PCE. [Display omitted] • Topological transformation of PCE helps to enhance effectiveness via more adsorbed points per unit volume. • SPCE molecules adsorb as a flat conformation to present a low and compact layer on cement surface. • Rheological properties of cement pastes depend on the interparticle steric force which plays a dominant role. • Good agreement is shown among the measured adsorbed layer thickness, R h value and surface coverage. • Novelty changing to dense topological structure is proved as a promising way to obtain highly effective PCE. [ABSTRACT FROM AUTHOR]

China was positioned as the world's largest producer and consumer of ceramic tiles, accounting for 50% of tile production and 40% of tile consumption in the world approximately. Recently, Chinese ceramic industry has increased its focus on environmental issues with the aim of protecting natural resources and reducing pollutant emission. This study evaluated and compared the environmental impacts of ceramic tiles produced by traditional technology and cleaner production technology using life cycle assessment methodology with "cradle to gate" perspective. The results showed that the energy consumptions and emissions from fuel combustion were the hotspots of the environmental impact caused by tile production. The drying and firing processes were the main contributors to the energy consumption at the ceramic production stage. Moreover, the environmental impact reduction potential of different cleaner production technologies was elaborated in this paper. The results proved that applying natural gas as fuel instead of coal (producer gas) caused less damage on human health and ecosystem but more damage on the resource. The dry-milling process has potential to reduce environmental impacts compared with wet-milling process in all midpoint and endpoint indicators. In addition, the sensitivity analysis of input parameters, transportation distance and qualified products rate was conducted to identify the key parameters that have great influence on the results. • Ceramic products from four typical plants in China was analyzed using LCA. • Environmental impact of different fuel scenarios and milling technologies was compared. • Applying the natural gas as fuel instead of coal (producer gas) caused less damage on human health and ecosystem. • Dry-milling process have potential to reduce the environmental impact compared with wet-milling process. • Sensitivity analysis related to input parameter, transport distance and qualified products rate were conducted. [ABSTRACT FROM AUTHOR]

This study aims to analyze the effect of high-altitude environment on drivers' mental workload (MW), situation awareness (SA), and driving behaviour (DB), and to explore the relationship among those driving performances. Based on a survey, the data of 356 lowlanders engaging in driving activities at Tibetan Plateau (high-altitude group) and 341 lowlanders engaging in driving activities at low altitudes (low-altitude group) were compared and analyzed. The results suggest that the differences between the two groups are noteworthy. Mental workload of high-altitude group is significantly higher than that of low-altitude group, and their situation awareness is lower significantly. The possibility of risky driving behaviours for high-altitude group, especially aggressive violations, is higher. For the high-altitude group, the increase of mental workload can lead to an increase on aggressive violations, and the situation understanding plays a full mediating effect between mental workload and aggressive violations. Measures aiming at the improvement of situation awareness and the reduction of mental workload can effectively reduce the driving risk from high-altitude environment for lowlanders. [ABSTRACT FROM AUTHOR]

• The molecular dynamics (MD) technique was successfully applied to systematically investigate the interfacial interaction between epoxy resin with various crosslink densities and load-induced C-S-H broken panels. • Molecular interaction, pore volumes and interfacial energies were considered to investigate the interaction between epoxy resin and C-S-H gel. • Microcracks occurred to different regions (interfacial region or epoxy matrix) when uniaxial tensile deformation was applied to models. In epoxy-amine based self-healing cement-based materials, the uncontrollable stoichiometric ratio of both components in the cracks leads to the cured epoxy resin with various crosslink densities. Investigation on the interaction mechanism between cured epoxy resin and C-S-H gel promotes to optimize the final self-healing performances. In this work, the interaction between load-induced broken panels of C-S-H gel and cured epoxy resins with different crosslink densities (e.g., 0.23, 0.77, and 0.97) was studied through molecular dynamic methods. It was found that crosslink density plays an essential role in the geometrical size and atom distributions. Phase separation occurs at the low crosslink density due to the aggregation of amine molecules. The generation of fresh crosslink points limits the free motion of epoxy molecules with higher crosslink density. Meanwhile, the cured epoxy resin with higher crosslink density causes a high porosity in the interfacial region between the epoxy resin and C-S-H gel substrates, degrading the mechanical performance of materials. [ABSTRACT FROM AUTHOR]

• A certain dosage of DEA or TEA helps to increase the application performance of accelerator. • The complexation effect of DEA and TEA in accelerator have a significant difference. • DEA in accelerator promote the C 3 S hydration in the initial stage of hydration. • High dosage of TEA in accelerator increases the formation rate of AFt and inhibit the hydration of C 3 A and C 3 S. • Transformation of DEA-Al to DEA-Ca occurred in the cement hydration when accelerator containing DEA. In this study, diethanolamine (DEA) and triethanolamine (TEA) were used to prepare a series of liquid alkali-free accelerators to investigate the different effects of complexation of DEA and TEA in accelerators towards the initial stage of cement hydration. Two types of accelerators respectively containing DEA (dosages of 0, 6, 8, 10, 12%) and TEA (dosages of 0, 0.25, 0.5, 0.75, 1, 8%) were prepared, and after addition, the setting time of cement pastes and compressive strength of mortars were tested. The result showed that the optimum dosage of DEA and TEA in accelerators was 8% and 0.25% respectively, and the early-strength effect of TEA was stronger than that of DEA. The mechanisms of DEA and TEA in accelerators were further revealed in terms of complexation capacity, concentration of Ca2+, and hydration products and microstructure morphology of cement pastes. DEA and TEA complexed with Al3+ in accelerators and promoted the formation of ettringite (AFt) in cement pastes, and the complexation capacity of TEA to Al3+ was stronger than that of DEA, causing that high dosage of TEA in accelerator promoted the formation of AFt more than DEA and covered at the surfaces of C 3 A and C 3 S, which inhibited the hydration. DEA in accelerator could promote the hydration of C 3 S in the initial stage due to the transformation of complex DEA-Al to DEA-Ca. This study aims to interpret the different influences of complexation effects of DEA and TEA in accelerators on the properties of cement-based materials and their working mechanisms. [ABSTRACT FROM AUTHOR]

In the synthesis of functional polycarboxylate superplasticizers (PCEs), ester monomer was usually used as small monomer or macromonomer. However, there were few studies on the co-introduction of small ester monomer and ester macromonomer into one PCE molecule and its effects. In this study, it was found an interesting behavior of competitive hydrolysis between these two ester monomers in diester PCE, which performed higher fluidity of cement paste, greater adsorption amount and shorter prolongation of the induction period of cement hydration due to the competitive hydrolysis. Furthermore, the kinetics of hydrolysis and adsorption of the diester PCE were probed, and the rate order was: ester macromonomer < small ester monomer < diester monomers. This study aims to innovatively reveal the special behavior and mechanism of competitive hydrolysis of PCE using diester monomers in cement-based materials and to provide a theoretical basis for enriching molecular design and innovative application of functional PCEs. [Display omitted] • First study on the competitive hydrolysis behavior of PCE having complex diester. • Competitive hydrolysis occurred between small ester monomer and ester macromonomer. • The kinetics of hydrolysis and adsorption of the diester PCE were established. • Better performances in adsorption and dispersibility of diester PCE in cement paste. • Competitive hydrolysis helped reduce the prolongation of hydration induction period. [ABSTRACT FROM AUTHOR]

To solve the problem of high viscosity for fresh concrete especially high-grade concrete, a novel viscosity-reducing type of polycarboxylate superplasticizer (PCE) was synthesized based on innovative design of molecular structure, and also was characterized to confirm the designed molecular structure. The rheological performances of cement paste and fresh concrete containing synthesized PCE were probed, which were analyzed by means of surface tension, adsorption behavior and zeta potential. The plastic viscosity showed a good correlation with T50 and V-funnel time according to mesomechanics process model. Moreover, the investigation of working mechanism interestingly showed that lowering molecular weight and side chain length and introducing hydrophobic groups can achieve improved dispersion capacity and viscosity-reduction effectiveness. The aim of this study is to provide a promising avenue to synthesize PCE with superior workability and viscosity-reducing performance in fresh concrete. This new type of PCE can be used as a viscosity-reducing agent in concrete engineering. [ABSTRACT FROM AUTHOR]

[Display omitted] • Nearly vertically aligned ZnO nanorod arrays are formed on the α-Al 2 O 3 membranes. • The load of fluorocarbon groups has been raised. • A superhydrophobic surface with a water angle of 155° has been obtained. • The MTBE/water separation factor has been dramatically enhanced to 55.7 from 7.7. • The MTBE concentration has been significantly concentrated to 72.9 wt%. The separation of methyl tertiary butyl ether (MTBE) from aqueous solution by pervaporation-based membrane technology has attracted much attention recently. The present work proposed a novel strategy to enhance the MTBE/water separation performance of porous α-Al 2 O 3 membranes. ZnO seeds were planted on the surface of α-Al 2 O 3 membranes by the deposition and decomposition of zinc acetate, followed by growing ZnO nanorod arrays (ZNA) on the seeded α-Al 2 O 3 membranes by hydrothermal reaction in the mixed hydrated zinc nitrate (HZN) and hexamethylenetetramine (HMTA) solution. Finally, the membranes were hydrophobized by grafting fluoroalkylsilane (FAS) onto their surface. The results show that the MTBE/water separation factor has been dramatically promoted from 7.7 for the α-Al 2 O 3 membranes to 55.7 for the ZNA-covered α-Al 2 O 3 membranes. The promotion may be attributed to the nearly vertically aligned ZnO nanorod arrays, which provide much surface area to load more fluorocarbon groups that are amiable to MTBE molecules and supply a superhydrophobic surface. The MTBE in the permeate mixture has been concentrated to as high as 72.9 wt%, in striking contrast to 4.6 wt% in the feed solution. The obtained membranes are highly stable upon long-term operation. [ABSTRACT FROM AUTHOR]

Chemical admixtures are indispensable functional ingredients in modern construction, and their raw materials for synthesis are mainly sourced from petrochemical products, leading to petrochemical resource consumption and environmental damage. Using biomass as a raw material for preparing chemical admixtures for concrete is an effective and environmentally friendly method that holds great promise for overcoming these environment problems and obtaining exceptional application properties. This work systematically addresses the recent research advances in chemical admixtures using polysaccharide, polyphenol biomass and biorefineries, including their preparation methods, application effects and environmental impact assessment. The results show that the molecular structures of polysaccharide and polyphenol biomass contain a large number of active functional groups, which help bio-based chemical admixtures to be prepared by acylation, sulfonation and/or graft copolymerization, significantly improving the dispersibility, water retention, retardation, anti-adhesion and durability of cement-based materials. Also, the use of biorefinery technology endows chemical admixtures with superior environmental performance. In addition, this review addresses the importance of the life cycle assessment (LCA) method in evaluating the environmental impacts of bio-based chemical admixtures and establishes that environmental pollution can be substantially minimized by optimizing the preparation process (e.g., use of renewable raw materials, adoption of biorefineries, etc.). This article gives an overview on bio-based chemical admixtures and their high-value utilization and ecological development that provide a theoretical basis for the design of energy-saving and low-cost bio-based chemical admixtures. [Display omitted] • Potential application of biomass in preparation of environment-friendly admixtures. • Preparation processes of conventional and new bio-based admixtures were compared. • Bio-based admixtures show better properties and lower environmental impact. • Application of LCA methodology in preparation of bio-based chemical admixtures. • Performance and environmental benefits of biomass into bio-based admixtures. [ABSTRACT FROM AUTHOR]

Effects of disodium EDTA (EDTA-2Na) on hydration and mechanical properties of calcium sulphoaluminate-belite cement (CSBC) were investigated systematically. Results show that EDTA-2Na addition leads to visible changes in CSBC strength development. 0.50 % EDTA-2Na significantly enhances the compressive strength by 18 % and 23 % compared with the blank specimens at 7 d and 28 d, while reducing the strength at 8 h and 1 d. The content of the main hydration product (AFt) determines the strength development. At the early hydration stage, EDTA-2Na delays hydration of ye'elimite to form AFt, thus decreasing the early hydration degree of CSBC and increasing the porosity to reduce strength. In the presence of EDTA-2Na, the morphology changes of amorphous aluminum hydroxide (AH 3) facilitate the AH 3 -C 2 S-CaSO 4 reaction to increase AFt content and form a more condensed structure, thus enhancing the late strength. In this way, the strength development of CSBC mortars can be modified and regulated by EDTA-2Na. [ABSTRACT FROM AUTHOR]

A field survey and pot experiment were carried out to screen tolerant plants growing in cadmium (Cd)-polluted mining areas which were co-polluted with acid in soil, and the related physiological and biochemical mechanisms were also analyzed. Thirty-seven species of wild plants and their corresponding soil were collected from a farmland around the mining areas. Ageratum (Ageratum conyzoides L.) with strong Cd-accumulative ability was selected, and its tolerance experiment for acid and Cd with different levels were carried out separately or orthogonally, respectively. Furthermore, the activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), and the contents of malondialdehyde (MDA), photosynthetic pigments, soluble sugar and proline in its leaves were determined. The results showed that the Cd accumulation in ageratum and sticktight (Bidens pilosa L.) was relatively high, but the latter has been well documented, so we focused on ageratum in the present work. In pot experiment, ageratum grew normally at 100 mg kg−1 Cd in soil, and the Cd concentrations in its roots, stems and leaves were 75.37 ± 7.37, 31.01 ± 3.76 and 53.92 ± 10.05 mg kg−1, respectively. In the case of acid tolerance experiment, all plant individuals of ageratum grew normally when soil pH was over 3.5. In the orthogonal experiment, the Cd accumulation in this plant increased with the decrease of soil pH under the same Cd treatment. Under strong acid conditions, the activity of SOD in leaves of ageratum was increased significantly. When the Cd concentration was 10 mg kg−1 and the soil pH was 5.5 or 3.5, the activities of POD and CAT were significantly increased. In addition, based on stepwise regression analysis, the leaf Cd concentration was significantly positive correlated with the activities of SOD and POD in leaves of ageratum. Therefore, ageratum not only had a strong tolerance for Cd and acid pollution in soil, but also had a strong ability to accumulate Cd. As a common plant in the mining area, it has a great potential for the phytoremediation of Cd and acid co-contaminated soil. • A good plant candidate was found for soil environmental management of Cd and acid co-pollution. • About 54 mg kg−1 leaf Cd in ageratum was recorded when treated with 100 mg kg−1 Cd. • Ageratum grew healthily when soil pH was over 3.5. • The activities of SOD and POD had a significant positive correlation with leaf Cd concentration. • Ageratum had a potential for phytomediation of Cd and acid co-polluted soil with 3130 US$ hm−2. [ABSTRACT FROM AUTHOR]

[Display omitted] • The construction of reactive hydrophilic XPSF surface by the surface curing of UV curable adhesives. • The fabrication of chemical bonded XPSF/mortar interfaces. • The thorough investigation of the reactions between cured UV adhesive coating and XPSF surface. The hydrophobic surface of extruded polystyrene foams (XPSF) was modified by UV curable adhesives to enhance the interfacial bonding strength (BS) with mortar. The UV adhesive contained epoxy acrylate resin, acrylic acid and butyl acrylate (denoted as EAB). After EAB modification, the BS value in dry state (BS-D) increased from 0.050 MPa of unmodified XPSF with mortar to 0.210 MPa. Then, 3-aminopropyltriethoxysilane (APTES) was further introduced into EAB to form the water-resistant coatings (denoted as EABT) to enhance the BS value in wet state (BS-W). By optimizing the composition, the maximum BS-D and BS-W of 0.216 and 0.158 MPa in 7-day curing were obtained. The bonding mechanism illustrated that the modified XPSF was chemically bonded with mortar. [ABSTRACT FROM AUTHOR]

[Display omitted] • EDIPA greatly improves compressive strength and shortens setting time of SS paste. • Chelation of EDIPA promotes the formation of monocarboaluminate (C(A,F) C ¯ H) • The chelating ability of EDIPA to Al3+ and Fe3+ is stronger than that of Ca2+. • The chelation of EDIPA changes the crystal structure and morphology of Ca(OH) 2. The low cementitious activity of steel slag (SS) limits its application in cement-based materials. The effects of ethanol-diisopropanolamine (EDIPA) on the hydration and mechanical properties of pure basic oxygen furnace SS were investigated. The hydration kinetics and pore structure of SS pastes incorporated with EDIPA and the chelation of EDIPA were analyzed to reveal the working mechanism of EDIPA. The results show that EDIPA improves the compressive strength of the hardened SS paste and greatly shortens the setting time of SS paste, which is related to the chelation of EDIPA. EDIPA could chelate with Ca2+, Al3+, and Fe3+ to form metal chelates, and the chelating ability of EDIPA to Al3+ and Fe3+ is stronger than that of Ca2+. The chelation of EDIPA simultaneously promotes the hydration and carbonation of aluminate and ferrite phases (C 3 A, C 12 A 7 , and C 2 F), resulting in a large amount of monocarboaluminate (C(A,F) C ¯ H), thus improves the hydration degree of SS paste. EDIPA could refine the pore structure of hardened SS paste, which is mainly manifested as the decrease in the amount of macropores and pore size, and the increase in the amount of small pores. The chelation of EDIPA changes the crystal structure and morphology of Ca(OH) 2 , which is potentially helpful to weaken the negative effect of Ca(OH) 2 on strength. This study reveals the effect of chelation of EDIPA on the hydration of SS, which is a valuable guide for the resource utilization of SS. [ABSTRACT FROM AUTHOR]

This study was conducted based on the ISO 14040/14044 standards to analyze the environmental impact caused by blast furnace slag utilization for ordinary Portland cement production in typical plants in Beijing. In addition, sensitivity analysis of resource consumption, transport distance, the allocation methods and life cycle impact assessment model were discussed in detail. The results showed that global warming potential and acidification potential were the most significant environmental impacts resulted by slag-based cement production, accounting for 58.5% and 21.7% of the total environmental impact, respectively. Moreover, the cement production and energy generation phases accounted for 66.6% and 29.6% of total environmental loads of slag-based cement from cradle to gate, respectively. Sensitivity analysis showed that the comprehensive environmental impact of slag-based cement was sensitive to the consumption of limestone and energy, as well as the allocation methods and life cycle impact assessment model; but was insensitive to the consumption and transport distance of blast furnace slag. Compared with traditional Portland cement, except for the approximately 9% increase of human toxicity potential, the other impacts of slag-based cement decreased to a certain extent. In particular, abiotic depletion potential and land use potential significantly reduced by 72% and 41%, respectively. Therefore, producing cement with blast furnace slag would slightly increase electricity consumption, but significantly improve the benefits of land resource and materials conservation and significantly decrease the comprehensive environmental impact of cement. [ABSTRACT FROM AUTHOR]

This work aims to investigate the solubilizing ability of alkanolamines on steel slag (SS) and the chelating ability of alkanolamines with metal ions. In this paper, the chelation effect of four alkanolamines, including triethanolamine (TEA), triisopropanolamine (TIPA), diethanol-isopropanolamine (DEIPA), and methyl diethanolamine (MDEA), and metal ions on the dissolution of SS was investigated. The conductivity meter, pH meter, X-ray powder diffraction (XRD), inductively coupled plasma atomic emission spectroscopy (ICP-AES), total organic carbon (TOC) and isothermal calorimetry were used to investigate the solubilizing ability of SS impacted by alkanolamines. Additionally, the conductivity meter and chemical precipitation method (CPM) were used to investigate and explore the chelating ability of alkanolamines interacting with the metal ions. Finally, the nuclear magnetic resonance hydrogen (1HNMR) spectroscopy was adopted to investigate the chelating mechanism between alkanolamines and metal ions. The results showed that the alkanolamines increased the elemental concentrations of [Ca], [Al], [Fe] and [Si] in the liquid phase of SS through chelating and promoted the dissolution of the mineral phase of C 3 S, C 2 S and C 4 AF in SS. Among the different alkanolamines, DEIPA was present in the liquid phase for the longest time and possessed a more sustained ability to chelating metal ions. The result also shows that alkanolamines can chelate the Ca2+, Al3+ and Fe3+ in solution. The chelating ability of tertiary alkanolamines were stronger than the secondary alkanolamine. And the alkanolamine with asymmetric molecular structure have stronger chelating ability than those with symmetric molecular structure. Tertiary alkanolamines form ternary five-ring structure with metal ion through nitrogen and oxygen atoms. • Alkanolamines promoted the dissolution of the mineral phase in steel slag. • DEIPA possessed a more sustained ability to chelating metal ions. • Alkanolamine with asymmetric molecular structure have stronger chelating ability. • Ternary five-ring structure formed between the ternary alkanolamine and metal ion. [ABSTRACT FROM AUTHOR]

The use of new polymeric building block is one of the important routes to extend the layer-by-layer (LbL) assembly technique to fabricate novel nanofiltration (NF) membrane. In this work, the low cost sulfonated cyclohexanone–formaldehyde (SCF) condensation polymer is used as anionic building blocks to prepare a novel positively charged nanofiltration membrane by LbL self-assembly technique. The LbL assembly process was investigated by XRD, FTIR, SEM and AFM measurements. The separation performance of cationic ions and dyes was evaluated by pressure-driven nanofiltration tests. It is found that the multilayer surfaces exhibited periodic variations in positive charges. And the prepared membrane showed an effective rejection of both cationic ions and dyes. The multilayer membrane of 4.5 bilayers exhibited rejections of 92.8% and 90.6% to Ni 2 + and Ca 2 + , along with flux of 40.8 and 44.9 L/(m 2 ·h·MPa) and pure water flux of 49.3 L/(m 2 ·h·MPa), respectively. Simultaneously, this membrane also showed rejection of 93.7% and 90.8% to RdB and EbT, along with flux of 24.3 and 20.5 L/(m 2 ·h·MPa), respectively. Moreover, the long-term performance stability of the membrane was improved through cross-linking the multilayer membrane. [ABSTRACT FROM AUTHOR]

[Display omitted] • PU-UF MPCMs with binary esters as core and double-layered shell are synthesized. • The performance of PU-UF MPCMs in cement composites is investigated. • PU-UF MPCMs exhibit potential for enhancing energy savings and thermal comfort of buildings. In this study, novel microencapsulated phase change materials (PU-UF MPCMs) with methyl palmitate and methyl stearate as core and double-layered shell structure were designed for building energy conservations. Their composition, microstructure and thermal performances were determined by techniques including optical microscope (OM), scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Effects of PU-UF MPCMs on the thermal performance of cementitious composites were also investigated. Results show that PU-UF MPCMs with spherical shape and double-layered shell structure were successfully prepared. DSC results show that the latent heat of PU-UF MPCMs is 137.6 J/g and the melt temperature of cores in PU-UF MPCMs is 24.2 °C. 5%-15% PU-UF MPCMs addition increases the thermal storage capacity of cement pastes through a phase transition process, among which 15% PU-UF MPCMs leads to the highest thermal storage capacity. Those results suggest that PU-UF MPCMs exhibit the potential for enhancing energy savings and thermal comfort of buildings. [ABSTRACT FROM AUTHOR]

[Display omitted] • Porous SiO 2 @PDMS protective layer has been constructed on the top of FAS-modified ceramic membranes. • The presence of cavities within the layer helps to reduce the vapor transport resistance through membranes. • The layer shows robust hydrophobicity. • The desalination stability of FAS-modified ceramic membranes has been significantly enhanced. The production of freshwater by desalination has great significance. Membrane distillation (MD) is considered as a promising technique for desalination. As a popular candidate for MD desalination, FAS (fluoroalkylsilane)-modified ceramic membrane suffers from insufficient stability, such as membrane wetting and decline of salt rejection during long-term operation, because of the degradation of hydrophobicity. In the present work, a novel strategy is proposed to enhance the long-term desalination stability of FAS-modified cordierite ceramic membranes by constructing a porous SiO 2 @PDMS (polydimethylsiloxane) protective layer on their tops to obtain a robust hydrophobic property. The results show that such a layer can be successfully fabricated by a two-step spraying method with hydrosoluble NaCl particles as templates. The incorporation of SiO 2 nanoparticles into PDMS generates a loose and porous structure in the layer and renders an enhanced hydrophobicity. At a SiO 2 /PDMS mass ratio of 0.30, the membranes exhibit a notable resistance to both mechanical abrasion and chemical corrosion. The dissolution of NaCl templates leaves behind cavities within the layer, which prevents the SiO 2 /PDMS species from blocking the membrane pores and thereby helps to reduce the vapor transport resistance. These membranes are highly stable upon long-term desalination (>300 h) and can preserve a stable water flux of 8.10 kg/m2h and a salt rejection close to 100% under the following conditions: a feed temperature of 80 °C, a NaCl concentration of 3.5 wt% and a feed flow rate of 300 mL/min. The SiO 2 @PDMS layer is responsible for the outstanding desalination stability since it prevents membrane wetting by reducing the direct contact of the reflux feed solution to the underlying cordierite ceramic membranes. [ABSTRACT FROM AUTHOR]

Balancing the NH 3 selective catalytic reduction (NH 3 -SCR) and catalytic oxidation performance is difficult but necessary for the synergistic elimination of NO x and chlorine-containing volatile organic compounds (CVOCs). We herein unveiled that electronic structure tailoring of the applied catalyst was an efficient pathway for balancing the catalytic behaviors in the NH 3 -SCR of NO and chlorobenzene catalytic oxidation (CBCO). Specifically, environmentally friendly CeO 2 substituted by low valent Al3+ exhibited better NH 3 -SCR of NO and CBCO activity in comparison with the CeO 2 sample without doping. Detailed characterizations and theoretical simulations revealed that the strong dopant-oxide pairs in the CeO 2 with Al3+ doping significantly tailored the electronic structure of O 2p states, enhancing the amount of Lewis acid sites and promoting the ability of lattice oxygen to act as an oxidizing agent, thereby leading to superior performance for the synergistic elimination of NO/CB. The counterpart with substitution of high valent Ta5+ showed an opposite trend, due to that Ta5+ donated more electrons to the coordination oxygen than Ce4+ inhibiting lattice oxygen separating from the surface of the catalyst, and Lewis base sites were formed. [Display omitted] • Electronic structure tailoring could be achieved via metal doping. • Al-doped CeO 2 tailored the electronic structure of O 2p states. • Lewis acid sites and lattice oxygen ability of Al-doped CeO 2 was enhanced. • Al-doped CeO 2 exhibited better NH 3 -SCR of NO and chlorobenzene catalytic oxidation activity. [ABSTRACT FROM AUTHOR]