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Interpenetrating polymer networks (IPNs) possessing a wide damping temperature range are commonly employed as damping materials that are applied in numerous fields. But IPNs will gradually appear to fatigue microcracks and fracture when long‐term in the energy absorption and dissipation. So, the ability for IPNs to recover from damage is necessary that can considerably prolong their service life. Based on polyurethane elastomer and cross‐linked epoxy, several innovative self‐healing IPNs are designed and prepared in this research. The IPNs containing dynamic disulfide bond exhibit favorable damping and self‐healing properties. In detail, the loss factor of IPN‐80/20 is beyond 0.3 at temperatures between −0.8 and 65.5 °C that covers the operating temperature range at room temperature. What is more, The PU/EP IPNs also have excellent shape memory properties, self‐healing ability, and thermal stability. [ABSTRACT FROM AUTHOR]

• A theoretical modeling method for thin plate with multiple curved through cracks is presented. • Four different types of cracked thin plates were tested and verified. • Effects of the location, length and number of cracks are discussed. A modeling method for transverse vibration of cracked plate containing multiple internal curved through cracks is presented and experimental studies are performed to validate its effectiveness. The cracked plate is assumed to be divided into several rectangular and curved trapezoidal domains in the global coordinates system. For each sub-domain, the transverse displacement is expanded as Chebyshev orthogonal polynomials series in local coordinates system. As for the shared edges between neighboring two sub-domains, the local collocation method is adopted and a number of Chebyshev zero points are selected to ensure the displacement continuity condition. To verify the convergence and correctness of the presented model and solutions, the natural frequencies, mode shapes and dynamic responses for several cases are compared with reference results and experimental results, with good agreement observed. In addition, the influence of several significant parameters of cracks are investigated, including the number, location and geometrical shape of the cracks. It is shown that the crack inside the plate presents less influence than that at the boundary on the mode change of the plate. The investigations in the study implies that the present model method is effective and convenient for plate with multiple curved through cracks. [Display omitted] [ABSTRACT FROM AUTHOR]

There are few studies on denitrification related to the nitrogen cycle in Ebinur Lake wetland. This study aimed to explore the response of the diversity and composition of denitrifying bacteria to the environmental factors in wetland, so as to obtain more information about the community structure of denitrifying bacteria driven by environmental factors. Using the genes encoding nitrite reductase (nirS and nirK) as molecular markers, we analysed the seasonal changes in the diversity of denitrifying bacteria in halophyte soils by high-throughput sequencing technology. The results showed that the diversity of denitrifying bacteria was higher in July and lower in April, showing seasonal changes. The diversity index of denitrifying bacteria in rhizosphere soil was higher than that in non-rhizosphere soil. The diversity of denitrifying bacteria in the Phragmites australis rhizosphere soil was the highest. The diversity of nirK denitrifying bacteria was higher than that of nirS denitrifying bacteria, but the relative abundance was lower than that of nirS denitrifying bacteria. Three-way ANOVA showed that soil types, vegetation types and season had significant effects on the diversity of denitrifying bacteria. Furthermore, redundancy analysis indicated that nitrate was the environmental factor that significantly affected the community structure of nirS denitrifying bacteria in wetland, and electric conductivity, total nitrogen, ammonium and nitrate were the environmental factors that significantly affected the community structure of nirK denitrifying bacteria. These results provide data basis and theoretical support for the dynamic change of diversity of denitrifying bacteria in wetland. [ABSTRACT FROM AUTHOR]

Adsorption by nanoporous media is critically involved in many fundamental geological and geochemical processes including chemical weathering, element migration and enrichment, environmental pollution, etc. Yet, the adsorption behavior of metal ions on nanoporous materials has not been systematically investigated. In this study, MCM-41 material with a monodisperse pore size (4.4 nm) and a large BET specific surface area (839 m2/g) was hydrothermally prepared and used as a model silica adsorbent to study the adsorption characteristics of Cu2+ as a representative metal ion. The Cu2+ adsorption capacity was found to increase with increasing suspension pH in the range from 3 to 5 and to decrease in the presence of NaNO3. At 25 °C, pH = 5, and a solid-to-liquid ratio of 5 g/L, the adsorption capacity was determined to be 0.29 mg/g, which can be converted to a dimensionless partition coefficient of 45, indicating a strong enriching effect of nanoporous silica. The adsorption isotherm and kinetic data were fitted to several commonly used thermodynamic, kinetic, and diffusion models. The adsorption mechanism was also studied by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and synchrotron-based X-ray absorption spectroscopy. The results suggest that Cu2+ ion adsorption is an entropy-driven endothermal process, possibly involving both outer-sphere and inner-sphere complexes. [ABSTRACT FROM AUTHOR]

Asphalt in damp-heat and saline-alkali areas is prone to damage, which resulting in fatigue failure of the mixture. However, the aging damage of asphalt in these areas has not been paid enough attention, and there is a lack of effective evaluation method for asphalt's fatigue performance. In this paper, the base asphalt and SBS-modified asphalt were immersed in several solutions (water, NaCl and Na2CO3) to simulate aging conditions and the frequency sweep test was employed to determine the viscoelasticity properties of the asphalt. And the fatigue properties of the asphalt were analysed by the simplified viscoelastic continuum damage model. The microstructural and chemical evolution of asphalt was investigated by SEM, FTIR, the pH value and total organic carbon tests. After being immersed, the anti-deformation properties of two asphalts were strengthened. The solution erosion led to an increased loss rate of the integrity factor C*, and resulting in weakened fatigue properties of asphalt. The oxygen-containing functional group gradually increased with the extension of immersion. There were chemical interactions in addition to physical interface disruption during the immersion process. Moreover, the influence of Na2CO3 solution on asphalt ranked first due to the highest molar concentration of Na+ and the OH− produced by hydrolysis of ${\rm CO}_3^{2-}$ C O 3 2 − . [ABSTRACT FROM AUTHOR]

Reports have pointed out that nearly 50% of the global total energy demand for buildings is used for daily heating and cooling. Therefore, it is very important to develop various high-performance thermal management techniques with low energy consumption. In this work, we present an intelligent shape memory polymers (SMPs)-based device with programmable anisotropic thermal conductivity fabricated by a 4D printing technique to assist in thermal management with net zero energy. Highly thermal conductive BN nanosheets were textured in a poly (lactic acid) (PLA) matrix by 3D printing, and the printed composites lamina exhibited significant anisotropic thermal conductivity. The direction of heat flow in devices could be switched programmably, accompanying the light-activated deformation controlled by grayscale of composite, which was demonstrated by the "windows" arrays composed of in-plate thermal conductivity facets and SMPs-based hinge joints, achieving the programmable movement of opening and closing under different light conditions. Based on solar radiation-dependent SMPs coupled with the adjustment of heat flow along anisotropic thermal conductivity, the 4D printed device has been proved in concept for potential applications in thermal management in a building envelop for dynamic climate adaptation, taking place automatically based on the environment. [ABSTRACT FROM AUTHOR]

Abstract: In this work, we have proposed a sensitive and selective detection technique for 2-nonylphenol (2-NP) based on the differential pulse voltammetry at a molecularly imprinted film on a glassy carbon electrode (GCE). The imprinted film was immobilised on the GCE by electrodeposition of a molecularly imprinted polymer (MIP) sol–gel consisting of a multiwalled carbon nanotube (MWNT)–Nafion (NF) composite. The modification procedure was characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and scanning electron microscope (SEM). The recognition between MIP sol–gel film and target molecule was observed by measuring the change in DPV response of the oxidation-reduction probe, K3Fe(CN)6 on GCE. Under optimized operational conditions, a linear response was obtained covering the concentration range from 0.2 to 360μmolL −1 with a detection limit of 0.06μmolL −1. The proposed sensor was applied to 2-NP determination in water and soil samples with the recoveries from 95.4 to 98.1%, showing a promising potential application in environment samples. Additionally, The imprinted sensor demonstrated higher affinity for target 2-NP than that of non-imprinted polymer (NIP) sensor. [Copyright &y& Elsevier]

Cracking risk of cementitious materials remains one of the serious problems in the construction and highway field. Here, a series of pH-sensitive microgels with different anionic content and crosslinking density have been successfully synthesized and applied in cement mortar. The absorption behavior and pH sensitivity of microgel in aqueous solutions were determined. The effects of microgel on hydration degree, autogenous shrinkage, and compressive strength of cement mortar were studied. Experimental results indicate that the microgel exhibits less desorption in the pore solution and releases water timely in pH from 12–13. Despite the different anionic content of microgels, the addition of microgel with moderate crosslinking density is 0.19%∼0.31% , which can alleviate the autogenous shrinkage of cement mortar. The compressive strength of mortar can be increased by about 5.7 MPa by the microgels with low anionic content and moderate crosslinking density, thereby showing excellent internal curing effect. [ABSTRACT FROM AUTHOR]

Abstract: Lanthanide tris(2,4,6-tri-tert-butylphenolate)s are highly active initiators for ring-opening polymerization of ɛ-caprolactone to give polycaprolactone with number average molecular weight as high as 8.3×104 at 20°C in 20min in toluene. The effects of solvent, rare earth element, monomer/initiator molar ratio, monomer concentration, as well as polymerization temperature and time have been investigated. The kinetic studies of ɛ-caprolactone polymerization have indicated that the polymerization rate is first-order with respect to both monomer and initiator concentrations. The overall activation energy amounts to 39.3kJ/mol. Mechanistic studies show that the monomer inserts into the growing chain with the acyl-oxygen bond scission. [Copyright &y& Elsevier]

This account describes the synthesis, characterization, and applications to catalysis of dendrimer-encapsulated metal nanoparticles (DEMNs). These materials are synthesized by a template approach in which metal ions are sorbed into the interior of dendrimers and then subsequently chemically reduced to yield nearly size-monodisperse, zero-valent metal particles having dimensions of less than 4 nm. The dendrimer component of these composites serve not only as a template for preparing the nanoparticle replica, but they also stabilize the nanoparticle, make it possible to tune solubility, and enhance catalytic selectivity. These materials have been used for a broad range of catalytic reactions, including hydrogenations, Heck coupling, and Suzuki reactions, in water, organic solvents, biphasic fluorous/organic solvents, and supercritical CO2. In many cases it is very simple to recycle the dendrimer-encapsulated catalysts. In addition to monometallic DEMNs, bimetallic materials have also recently been prepared and their catalytic properties are reported. To cite this article: Y. Niu et al., C. R. Chimie 6 (2003). [Copyright &y& Elsevier]

The surface texture of asphalt pavement has a significant effect on skid resistance performance. However, its contribution to the performance of skid resistance is non‐homogeneous and subjects to local validity. There are also a few deep learning models that take into account the effective contact texture region. This paper proposes a convolutional neural network model based on the effective contact texture region, containing macro‐ and micro‐scale awareness sub‐modules. In this study, the asphalt mixture with varying gradations was designed to accurately obtain the effective contact texture region. Then, the textures were disentangled into macro‐ and micro‐texture scales by applying the fast Fourier transform and fed into the model for training. Finally, the area of effective contact texture region was calculated, and the effective contact ratio parameter was then proposed using the triangulation algorithm. The results showed that the effective contact texture area of pavement varies by the asphalt mixture type. The effective contact ratio parameter exhibited a significant positive correlation (Pearson correlation coefficient is 0.901, R2= 0.8129) with skid resistance performance and was also influenced by key sieve aggregate content from 2.36 to 4.75 mm. The data of effective contact texture region following disentanglement significantly released the model performance (the relative error dropped to 1.81%). The model exhibited improved precision and performance, which can be utilized as an efficient, non‐contact alternative method for skid resistance analysis. [ABSTRACT FROM AUTHOR]

In the present study, the effect of elastomer ratios in solution-based mixtures on the formation of the phase structure and properties of compositions based on butyl rubber, chlorobutyl rubber, and ethylene-propylene-diene rubber was investigated. This work determined the influence of the elastomer ratios in uncured blends and their impact on the patterns of phase structure formation in multicomponent polymer systems, alterations in molecular mobility, and their influence on ozone resistance. Attenuated total reflectance – Fourier transform infrared spectroscopy was employed to analyze the chemical structure of the polymer surfaces. The influence of blend ratio (mass percentage ratios of 100/0, 80/20, 60/40, 50/50, 40/60, 20/80, and 0/100) on the phase structure and surface ozone oxidation was studied. The green strengths of the blends of ethylene-propylene-diene rubber and butyl/chlorobutyl rubbers were studied over a wide range of blend ratios. [ABSTRACT FROM AUTHOR]

As one of the important internal curing agents for cement-based materials, inorganic/organic composite water absorbing materials, which has hydrophilic groups and three-dimensional network structures, exhibits excellent water absorption, water retention, and water release properties. By introducing inorganic/organic composite water absorbing materials into cement-based materials, their water absorption and release characteristics can automatically adjust the internal relative humidity of cement-based materials, promote hydration reactions, reduce self shrinkage and early cracking of cement-based materials, and thereby improve mechanical properties and durability. The preparation methods, structural characteristics and absorption/desorption behavior of inorganic/organic composite internal curing materials (CICA) were introduced. The impact on the hydration process, microstructure, macroscopic properties and durability of cement-based materials were summarized. The development prospects of CICA in concrete applications were prospected, providing theoretical guidance and technical reference for the application of CICA in cement-based internal curing. [ABSTRACT FROM AUTHOR]

High-temperature rutting is one of the common forms of pavement damage. To further improve the high temperature performance of crumb rubber modified asphalt (CRMA) pavement, heavy calcium carbonate (HCC) modified by sodium pyrophosphate was combined with crumb rubber to prepare composite modified asphalt binder. Their physical properties, viscoelastic properties and chemical composition were investigated through conventional physical tests, DSR, FTIR and fluorescence microscopes. The results show that with the increase of HCC content, the mixing and compaction temperatures of composite modified asphalt binders continued to increase. Further, the high temperature performance and fatigue resistance of binders were better than the original CRMA, due to the enhanced lipophilicity of HCC after modification. It can be found from the FTIR spectrum that the addition of HCC only existed in physical action. However, excessive HCC would cause agglomeration of the asphalt matrix, so the optimum dosage of HCC was determined to be 4%. [ABSTRACT FROM AUTHOR]

Na 0.5 Bi 0.5 TiO 3 (NBT)-based ceramics are promising lead-free candidates for energy-storage applications owing to their individual crystal structure and phase transition information. However, the high coercive field (E C) and large remnant polarization (P r) are detrimental for practical applications. In this work, the composition-dependent phase structure, micromorphology, dielectric and energy storage properties of (1-x)(0.94Na 0.5 Bi 0.5 TiO 3 -0.06BaTiO 3)-xBi(Mg 2/3 Nb 1/3)O 3 (NBBT-100xBMN, x = 0.18, 0.20, 0.22 and 0.25) ternary ceramics were hereby investigated. The addition of BMN facilitates the phase transformation from rhombohedral (R3c) to tetragonal (P4bm), which is beneficial for the enhancement of relaxation behavior, and meanwhile impels the grain growth. Combined with the influence of grain size on breakdown field strength, an optimal recoverable energy storage density (W rec) of 1.88 J/cm3 with a high energy storage efficiency (η) of 82.15% was achieved in the NBBT-20BMN ceramic composition under the dielectric breakdown strength (DBS) of 150 kV/cm, accompanied by the excellent temperature stability from room temperature to 200 °C. All these manifest that the NBBT-20BMN ceramics have an attractive application prospect in the energy storage field. [ABSTRACT FROM AUTHOR]

• The compaction process of asphalt mixture was simulated in the laboratory. • The migration and rotation characteristics of aggregate particle was analyzed during asphalt mixture compaction. • The development of surface texture was explored during asphalt mixture compaction. • The compaction mechanism of asphalt mixture was discussed in combination with the Stribeck curve. Pavement performance is not only affected by materials and production but also by compaction quality. This paper investigates the migration and rotation law of coarse aggregate during asphalt mixture compaction using the statistical means based on 2D image analysis. The variation of surface texture during compaction was extracted by laser scanner, and its anti-sliding performance was tested. The compaction mechanism was then discussed in combination with the Stribeck curve. The results show that mixtures with different gradations required different compaction energy during compaction, the AC-13 mixture was easier to compacted than the SMA-13. The aggregate contact developed rapidly in the early compaction stage in the horizontal direction but increased gradually in the vertical direction. With the compaction, the radial angle of the aggregate tended to be consistent in the horizontal direction and the major axis of the aggregate approached to the horizontal axis in the vertical direction. At the same time, the aggregates on the surface of the mixture were embedded with each other with compaction, and the surface structure gradually decreased. Combined with the aggregate contact, asphalt mortar viscosity and the Stribeck curve theory, the compaction process of asphalt mixture could be divided into pre-mixed lubrication dominated by asphalt lubrication and post-mixed lubrication dominated by aggregate contact. The research results offer a reliable basis for studying the compaction mechanism and improving the construction quality control of the asphalt pavement. [ABSTRACT FROM AUTHOR]

To reduce vehicle exhaust gas pollution in transport-intensive roadways and tunnels, six types of photocatalytic asphalt binders were designed using graphite-phase carbon nitride (g-C3N4) and nanoscale titanium dioxide (nano-TiO2) particles. In this paper, the rheological behaviors and fatigue life of the nano-TiO2-modified asphalt binder (TiO2-MA) and g-C3N4-modified asphalt binder (C3N4-MA) were investigated. NO degradation capacity of six types of photocatalytic asphalt binders was characterized under visible light conditions. The results showed that TiO2-MA had more excellent rheological behaviors and rutting resistance than C3N4-MA. In addition, 4 wt% nano-TiO2 markedly improved the rheological behaviors and rutting resistance of MA compared to other dosages. TiO2-MA exhibited higher fatigue resistance. The fatigue life of TiO2-MA with 4 wt% nano-TiO2 was increased to 234.1% at 2.5% strain and 242.5% at 5% strain, respectively, compared to base asphalt binder (BA). C3N4-MA had better NO degradation capacity than TiO2-MA. Meanwhile, the NO degradation efficiency of C3N4-MA reached 17.8% with 5 wt% g-C3N4. [ABSTRACT FROM AUTHOR]

Near the coast of China, a large amount of sediment is produced during construction work. In order to mitigate the environmental damage caused by sediment and enhance the performance of rubber-modified asphalt effectively, solidified silt material and waste rubber were prepared to modify asphalt, and its macroscopic properties, such as viscosity and chemical composition, were determined via a routine physical test, DSR, Fourier Transform Infrared Spectroscopy (FTIR), and Fluorescence Microscopy (FM). The results show that, with the increase in powder particles and the addition of a certain amount of hardened mud, the mixing and compaction temperature of modified asphalt can be significantly increased—still reaching the design standard. In addition, the high thermal stability and fatigue resistance of the modified asphalt were clearly better than those of the ordinary asphalt. From the FTIR analysis, rubber particles and hardened silt only exhibited mechanical agitation with the asphalt. Considering that excessive silt might result in the aggregation of matrix asphalt, the addition of an appropriate amount of hardened solidified silt material can eliminate the aggregation. Therefore, the performance of modified asphalt was optimum when solidified silt was added. Our research can provide an effective theoretical basis and reference values for the practical application of compound-modified asphalt. Therefore, 6%HCS(6:4)-CRMA have better performance. Compared to ordinary rubber-modified asphalt, the composite-modified asphalt binder has better physical properties and a more suitable construction temperature. The composite-modified asphalt uses discarded rubber and silt as raw materials, which can effectively protect the environment. Meanwhile, the modified asphalt has excellent rheological properties and fatigue resistance. [ABSTRACT FROM AUTHOR]

A novel electrochemical sensor based on molecularly imprinted polymer membranes (MIPM) as biomimetic molecular recognition element involved in o -aminothiophenol functionalized Au nanoparticles (ATP@AuNPs) modified gold electrode was constructed for sensitive and selective detection of herbicide simazine (SMZ). The nano-scaled MIPM, with high specific surface area, was prepared by self-assembly of o -aminothiophenol (ATP) and electrodeposition of ATP@AuNPs in the presence of template SMZ. Cathodic current of SMZ was measured by cyclic voltammetry and the results exhibited that the proposed sensor possess a high electrocatalytic activity at a negative potential and a fast rebinding dynamics towards the reduction of SMZ in 0.01 M H 2 SO 4 solution (pH 1.7). Linear dependency of peak current on SMZ concentrations was observed from 0.03 to 140 μM and detection limit was estimated to be 0.013 μM (3S/N). The enhancement of sensitivity was attributed to the presence of gold nanoparticles (AuNPs) which decreased the electron-transfer impedance and increased imprinting sites, lead to the superior enrichment effect of the trace amount of SMZ in aqueous solvent. The developed SMZ imprinted sensor exhibited excellent long-term stability and acceptable repeatability. In addition, the proposed method was successfully applied to measure SMZ in several real samples with the spiked recoveries changing from 91.4% to 96.8%, showing a promising potential in practical application. [ABSTRACT FROM AUTHOR]

The introduction of superabsorbent polymers into cement increases the number of macroscopic pores, resulting in reduction of compressive strength. These limitations can be addressed by incorporated nano silica in polymer structure. Herein, a series of composite microgels containing nano silica were prepared and incorporated into cement paste. The effect of composite microgels on the hydration degree, compressive strength of cement paste was investigated. The microstructure and affected zone of cement paste were characterized by nitrogen adsorption desorption (NAD), backscattering (BSE), thermogravimetry (TGA) and microhardness techniques. The equilibrium absorptivity and water release rate of the composite microgels can be improved by proper crosslinking density and silica content. The addition of low crosslinking density composite microgels accelerated the formation of hydration products, which encouraged to filling formed voids. More dense arch structure was observed in vicinity of formed void. These further suggested that the reduction in the compressive strength of cement paste can be offset by composite microgels with proper crosslinking density, thus providing important application prospects in internal curing. [ABSTRACT FROM AUTHOR]

Bi 0.5 Na 0.5 TiO 3 (BNT) lead-free ceramics have been extensively studied due to their excellent dielectric, piezoelectric and ferroelectric properties. The phase structure and functionalities of BNT can be feasibly adjusted by doping/forming solid solutions with other elements/components. In this work, Bi(Mg 2/3 Nb 1/3)O 3 (BMN) was introduced into BNT by a conventional solid-state reaction to form a homogeneous solid solution of (1-x)(Bi 0.5 Na 0.5)TiO 3 -xBi(Mg 2/3 Nb 1/3)O 3 (BNT-xBMN) with a perovskite structure. With the increase of BMN content, a phase transition from rhombohedral R3c to tetragonal P4bm has been confirmed by XRD, along with shifting the ferroelectric-paraelectric phase transition temperature to lower temperatures with broadening dielectric peaks. Furthermore, an optimized recoverable energy density of 1.405 J/cm3 was achieved for BNT-0.10BMN ceramics under a low applied electric field of 140 kV/cm, which is mainly attributed to the transformation from ferroelectric to ergodic relaxor phase. [ABSTRACT FROM AUTHOR]

For the preventive maintenance engineering of special pavements such as ultra-thin friction courses and bridge deck pavements, the performance requirements of the utilized high-viscosity asphalt, including the resistance to permanent deformation, cracking ability, durability, and recyclability, are becoming increasingly stringent. In this study, based on the click reaction principle of carbon-carbon double (C C) bond, hydroxyl-terminated polybutadiene (HTPB) and isophorone diisocyanate (IPDI) were selected as the raw materials to synthesize thermoplastic polyurethane (TPU), and then 4,4'-disulfanediyldiphenol (DSDDP) was introduced as the chain extender to design a high-viscosity thermoplastic polyurethane modified asphalt (PUA). Subsequently, the mechanical and rheological properties of PUA under different types of chain extenders and polyurethane (PU) contents were tested, and the microstructure and modification mechanism were investigated at multiple scales. The results indicated that after the introduction of DSDDP, the basic physical properties and viscosity of PUA were greatly enhanced, the fluidity was significantly reduced, and excellent deformation and cracking resistance were achieved at various temperatures. The microscopic tests revealed that the viscosity enhancement effect mainly originated from the click reaction between the disulfide (S-S) bonds in DSDDP and the C C bonds on the soft segments of PU, which can further crosslink the linear PU molecular chain and form a dense spatial network structure to restrict the flow of macromolecules. The dynamic exchange of some S-S bonds facilitates the repetitive opening of the PUA network structure at high temperatures, so the PUA still exhibits thermoplasticity at high temperatures, which verifies the feasibility of the proposed design. Moreover, the addition of DSDDP reduced the degree of microphase separation of PUA, so the designed PUA can effectively adapt to various temperature environments. Overall, the findings of this study can boost the application of this novel PUA in the thin surface layers of high-performance pavements. [Display omitted] • The click reaction principle is applied to polyurethane modified asphalt (PUA) system. • Formed carbon-sulfur bonds provide PUA with high viscosity and excellent mechanical properties. • The PUA has a thermoplastic three-dimensional network structure that is partially reversible. • The designed PUA is a suitable material for high-performance pavement surface thin layer. [ABSTRACT FROM AUTHOR]

In order to improve the initial color and the long-term heat stability of super-transparent polyvinyl chloride (PVC), a series of composite heat stabilizers consisting of unsaturated Zn oleate and uracil derivatives have been designed in this paper. The uracil derivatives are 1,3-dimethyl-6-amino-uracil (DAU) and 6,6′-diamino-1,1′,3,3′-tetramethyl-5,5′-(ethylidene)bisuracil (OSU). The static thermal stability, dynamic thermal stability, and transparency were used to evaluate the properties of the stabilized transparent PVC sheets. The results indicate that the compatibility between the stabilizer and PVC was greatly enhanced by introducing an unsaturated long-chain Zn oleate and a long alkyl chain bisuracil derivative. Through the thermal discoloration test, the best ratio of DAU/zinc oleate (DAU/Zn) and OSU/zinc oleate (OSU/Zn) was determined to be 4:1, with a total amount of 3 phr in 100 phr PVC. It was verified that the combination of zinc oleate with uracil derivatives could improve the long-term thermal stability of PVC, and the DAU/Zn was better than that of the OSU/Zn. In addition, through the transmission/haze verification, adding a proper amount of epoxidized soybean oil (ESBO) and phosphite ester to the OSU/Zn system has a certain synergistic effect. The thermal stability and transparency of PVC can be remarkably enhanced. [ABSTRACT FROM AUTHOR]

[Display omitted] • Carbonized melamine foam-supported Co-doped Fe 2 O 3 was prepared via hydrothermal method. • Superior catalytic activity of CMF/Co-Fe 2 O 3 for peroxymonosulfate was observed. • The readily recyclable CMF/Co-Fe 2 O 3 heterogeneous catalyst benefits the practical application. Co-doped Fe 2 O 3 /carbonized melamine foam heterogeneous catalyst (CMF/Co-Fe 2 O 3) was prepared by hydrothermal method. Rhodamine B (RhB) degradation was employed as a model test for evaluating peroxymonosulfate (PMS) activation. The degradation efficiency of RhB can reach 97 % in the catalyst dosage (50 mg/L), PMS concentration (100 mg/L), pH = 7 and RhB initial concentration (10 mg/L) after 60 min reaction. The reaction rate constant is 10 times higher than that of CMF/Fe 2 O 3 and the activation ability of PMS is greatly improved. The degradation efficiency of RhB can be inhibited by increasing the initial mass concentration of RhB and pH value. The effect of temperature on the degradation rate of RhB conforms to the Arrhenius model, and the degradation process is a surface reaction controlled process. The results of free radical capture experiments and electron paramagnetic resonance (EPR) experiments showed that SO 4 ¯ was the main active free radical for RhB degradation. After four cycles, the degradation efficiency of RhB still maintains 80 % with CMF/10 %Co-Fe 2 O 3 catalyst. The heterogeneous catalyst exhibited potential application in the field of degradation of dye wastewater due to its excellent cycling stability. [ABSTRACT FROM AUTHOR]

Ebinur Lake Wetland is an understudied desert wetland ecosystem, particularly regarding nitrogen cycling. This study aimed to ascertain the diversity and richness of nitrogen-fixing bacterial communities in the Ebinur Lake Wetland. The diversity of the nitrogen-fixing bacteria community of nifH genes from the rhizosphere and non-rhizosphere soils of four plants in different seasons were examined using Illumina HiSeq PE250 high-throughput sequencing technology. The correlation between soil environmental factors and diversity and richness of nitrogen-fixing bacteria was studied using the redundancy analysis (RDA). The results showed that the diversity of nitrogen-fixing bacteria in the rhizosphere soil of the constructive plants was higher than that in the non-rhizosphere soil; also, the diversity in July was higher than that in October and April. Geobacter, Pseudomonas and Bradyrhizobium were the dominant common bacteria in different samples of Ebinur Lake Wetland. The RDA showed that the total nitrogen, available potassium and available phosphoruswere significantly correlated with the diversity and richness of nitrogen-fixing bacteria. The diversity and community structure of nitrogen-fixing bacteria in soil samples also changed over time. The community structures of nitrogen-fixing bacteria in the rhizosphere and non-rhizosphere soils of the four plants were not the same during the same period. The correlation between soil environmental factors and the community structure and abundance of nitrogen-fixing bacteria can provide data basis and theoretical support for the degradation and restoration of Ebinur Lake Wetland. [ABSTRACT FROM AUTHOR]

• A self-cleaning photocatalytic WO 3 -TiO 2 nanorod/PDMS coating. • The mutual benefit effect of self-cleaning and photocatalysis. • Visible-response photocatalytic NO degradation and self-cleaning performance. • The durable superhydrophobicity for external building wall. Practical significance in terms of the long-term effective application of photocatalytic coatings is greatly challenged by its easy pollution and poor self-cleaning performance. In this paper, a self-cleaning photocatalytic WO 3 -TiO 2 nanorod (MWT) /PDMS building coating (MWT coating) was prepared by spraying methods. The surface hierarchical structure fabricated by MWT and PDMS was a crux to construct a superhydrophobic surface, which endowed MWT coating with self-cleaning performance. Besides, the MWT coating exhibited prominent durability and antifouling property after 450 d practical application of the external wall. The excellent self-cleaning property of the coating was confirmed by the removal and resistance to the adhesion of powder particles. Meanwhile, the photocatalytic properties of MWT endowed MWT coating with the ability to degrade organic pollutants on the surface. The color difference of the coating polluted by methyl red was only 1.18 and 4.77 after 24 h UV and visible irradiation, respectively. This mutual benefit effect of self-cleaning and photocatalysis was also reflected in the degradation of NO. In the first five cycles, the degradation efficiency of NO decreased by 4.74% gradually under visible light due to the adhesion of oxidation products, and most of the MWT on the coating surface was regenerated after flushing, the PCD efficiency increased by 3.71%. Furthermore, after 30 days of outdoor weathering test, the PCD efficiency of MWT coating decreased by 11.74% and 12.05% under UV and visible light, respectively, which lays a foundation for the long-term effectiveness of the MWT coating in the process of use. [ABSTRACT FROM AUTHOR]

The aim of this study was to reveal the differences in the community structure of ammonia-oxidizing archaea (AOA) between rhizosphere and non-rhizosphere soil, to provide a theoretical basis for further study on the relationship between halophyte rhizosphere soil microorganisms and salt tolerance. The results of diversity and community structure showed that the diversity of the AOA community in rhizosphere soil of Reeds was higher than that in non-rhizosphere soil in spring and lower than that in non-rhizosphere soil in summer and autumn. In summer, the diversity of rhizosphere soil of Karelinia caspica was higher than that of non-rhizosphere soil and lower than that of non-rhizosphere soil in spring and autumn. The diversity of rhizosphere soil of Halocnemum strobilaceum in 3 seasons was lower than that in non-rhizosphere soil. The diversity of rhizosphere soil of Salicornia was higher than that in non-rhizosphere soil in 3 seasons. In addition, the relative abundance of AOA in rhizosphere soil of 4 plants was higher than that in non-rhizosphere soil. The AOA community in all soil samples was mainly concentrated in Crenarchaeota and Thaumarchaeota. Redundancy analysis results showed salinity, soil water moisture, pH, and soil organic matter were important factors affecting the differentiation of AOA communities. [ABSTRACT FROM AUTHOR]

[Display omitted] • (K 0.5 Na 0.5)Nb 1-x Bi x O 3 piezo-photocatalytic catalyst was designed by introducing Bi 2 O 3 in (K 0.5 Na 0.5)NbO 3 to construct point defects (such as V 0 ∙ ∙ , Bi(3−x)+ , B i Nb ″). The formation of defects facilitated the establishment of hybrid energy levels, thus reduced the band gap and increased the carrier concentration. • The built-in electric field established by means of the piezoelectricity of (K 0.5 Na 0.5)Nb 1-x Bi x O 3 , together with the strong bonding of B i Nb '' - h + defect pairs, further reduced electron-hole recombination in the catalytic process. • Under the synergistic effect of defects and built-in electric field, the composition of (K 0.5 Na 0.5)Nb 0.98 Bi 0.02 O 3 obtained the prominent piezo-photocatalytic performance as well as outstanding stability and reutilization, with the degradation of ∼95 % Rh B in 20 min and nearly 100 % Rh B in 60 min, which is brilliant in previous reports on KNN-based catalysis. • A novel strategy for boosting carrier separation by the synergistic interaction of a built-in electric field and point defect construction has been put forward. Semiconductor photocatalysts have been widely researched in wastewater treatment and photocatalysis predominantly depends on the redox reaction of photoinduced charge carriers on semiconductor surface. Afterwards, photoinduced carrier concentration and the effective separation of electrons and holes have been proved to be pivotal in promoting photocatalytic efficiency. Further, the internal electric field established by polarization of piezoelectric materials is considered an efficient means of separating electrons and holes. Hence, as a typical representative of piezoelectric materials, (K 0.5 Na 0.5)Nb 1-x Bi x O 3 was designed and prepared by introducing Bi 2 O 3 in (K 0.5 Na 0.5)NbO 3 to construct defects intentionally, and thus reduce the band gap and increase carrier concentration by the hybrid energy levels, for another promote efficient separation of electrons and holes by virtue of the built-in field created by piezoelectric polarization and pinning holes by defects. Thereinto, the K of Rh B degradation by (K 0.5 Na 0.5)Nb 0.98 Bi 0.02 O 3 reached 0.07846 min−1 under the combined light irradiation and ultrasonic, meanwhile 95 % Rh B can be degraded within 20 min and nearly 100 % in 60 min with eminent cycling stability, which is brilliant than previous reports on KNN-based catalyst. This work provides not only a novel piezo-photocatalytic degradation material but also a built-in electric field and defect synergy strategy for boosting carrier separation. [ABSTRACT FROM AUTHOR]

[Display omitted] Improving the separation efficiency of photo-generated charge carriers is an important strategy to enhance the photocatalytic performance. In this paper, the NaNbO 3 /WO 3 composite photocatalyst was prepared via a hydrothermal method, which exhibited a substantial increase in photocatalytic activity through the synergetic effect of visible light irradiation and ultrasound vibration. The XRD, FT-IR, Raman, SEM, XPS, UV–vis DRS, and photoluminescence spectroscopy results indicated that a large number of WO 3 particles were tightly attached to the surface of NaNbO 3 nanowires in the NaNbO 3 /WO 3 composite catalyst. Under the piezo-photocatalysis condition, the degradation efficiency of Rhodamine B (RhB) by 5 % NaNbO 3 /WO 3 was significantly improved, reaching 73.7 % within 120 min. Meanwhile, the piezo-photocatalytic degradation efficiency of the NaNbO 3 /WO 3 composite catalyst was increased by 30.1 % compared to single photocatalysis, and the corresponding reaction rate constant (K) was 2.23 times than that of single photocatalysis. In addition, quenching tests showed that h+ was the primary active species in piezo-photocatalytic process. The significant enhancement of piezo-photocatalytic performance was attributed to the piezoelectric field caused by the bending deformation of the NaNbO 3 nanowires, which was an important driving force for photo-generated charge carrier separation. Furthermore, the production of multiple redox active sites simultaneously improved the photocatalytic performance. [ABSTRACT FROM AUTHOR]

[Display omitted] • A CR/polyurethane modified asphalt sealant was prepared by the in-situ polymerization method. • The high and low temperature rheological properties of sealant were all excellent. • The PU phase was uniformly dispersed in asphalt quantified by fluorescence images. • The sealant has achieved great effects in the treatment of pavement cracks on site. Under the long-term effect of loads and climate conditions, various diseases can appear on the surface of asphalt pavement, causing deterioration in its performance. To address the pavement surface cracks during service, the present study developed a crumb rubber/polyurethane (CR/PU) compound as the modified asphalt sealant with excellent properties. The optimal material proportion, ensuring the best asphalt compatibility was selected to meet the requirements of standard hot-poured sealants for pavement. Additionally, the fineness and content of CR were determined. The research investigated rheological properties, aging performance, microstructure, and modification mechanism of the CR/PU sealant was then applied in an engineering project to evaluate its effectiveness in treating pavement cracks, and suitable construction techniques were summarized. The results revealed that the in-situ polymerization method is an appropriate approach for preparing the CR/PU sealant, demonstrating good high-temperature deformation resistance and low-temperature crack resistance, indicating synergistic interactions between CR and PU. Among various compositions, the sealant with 30 %PU and 15 %CR content exhibited the best thermal oxygen and UV aging properties. Microscopic tests indicated that CR was physically blended with asphalt, while PU underwent chemical modification and formed a cross-linked network structure with asphalt, resulting in CR dispersion around it, enhancing the thermal stability of the system. Furthermore, the test section displayed an ideal crack treatment effect, demonstrating the sealant's excellent sealing, durability, and watertight capacity. [ABSTRACT FROM AUTHOR]

• Quantitative determination for SBS content of aged modified asphalt by FTIR and potentiometric titration tests. • The rheological properties were investigated after TFOT and long-term aging of modified asphalt. • The actual SBS content versus the rheological indexes of aged modified asphalt can be well-fitted. The content of styrene–butadiene–styrene (SBS) modifier has a significant influence on the physical and chemical characteristics of asphalt. However, determining the SBS content in SBS modified asphalt (SBS MA) after aging remains a challenge. To facilitate the understanding of the relationship between physical properties and SBS content, the Fourier transform infrared (FTIR) and potentiometric titration test were utilized to detect SBS content of aged binders. In this paper, radial and linear SBS were incorporated into asphalt binders at three levels, and their rheological properties were investigated after thin film oven aging (TFOT) and long-term aging. Furthermore, the actual SBS content versus the rheological index at different aging stages was investigated. The results showed that both I C=C and Na 2 S 2 O 3 titration volume highly correlated with SBS content (R2 > 0.99), and there was only a slight difference between the actual content of SBS determined by the two methods. The fatigue resistance, high-temperature elastic, and low-temperature cracking characteristics of asphalt were weakened after aging, due to SBS degradation, especially in the early stage. In addition, the resistance to deformation, elastic recovery, anti-fatigue properties of radial SBS MA were superior to that of linear SBS MA at the same SBS content, while the low-temperature cracking performance demonstrated an opposite trend. The actual SBS content versus the rheological indexes after aging can be well-fitted by a nonlinear equation. Therefore, FTIR and potentiometric titration tests can effectively predict SBS content and analyze the aging degree of SBS MA. [ABSTRACT FROM AUTHOR]

• A nitric oxide removal coating was constructed by loading doped TiO 2 /AC photocatalyst on waterborne acrylic coating. • Under visible light irradiation, the NO degradation efficiency of doped TiO 2 /AC coating was 45.8 % in 2 h, and only decreased by 5.8 % after 5 cycles. • UV stability of doped TiO 2 /AC coating was investigated, and the mechanism of improving UV stability was proposed. • After 42 d UV aging and single water flushing, the NO removal efficiency of doped TiO 2 /AC coating still reached 36.7 % and exhibited excellent UV stability. Based on the porous structure of activated carbon (AC) and the photo-oxidation behavior of TiO2, a visible-light-responsive photocatalytic coating with UV stability was constructed by loading Fe/N/Co-TiO2@AC (DTC) on waterborne acrylic coating. The DTC with adsorption and degradation synergistic effect was prepared by a simple mechanochemistry method and characterized by UV–vis, SEM, XRD, and BET. The nitric oxide (NO) removal efficiency of DTC was 51.6 % under visible light in 2 h. Besides, under the same conditions, the NO removal efficiency of the DTC coating still reached 45.8 %. Further, to investigate the UV stability of DTC coating, different coatings were prepared with the same dosage of DTC, TiO 2 @AC (TC), and TiO 2. The UV stability of the coatings was tested with a color difference, degree of chalking, adhesion strength, hardness, and impact resistance as evaluation indicators. The results showed that the DTC coating exhibited the best UV stability. The photooxidation of organic binder on the coating surface before and after aging was micro-characterized by SEM and FT-IR, and the UV stability improvement mechanism was revealed. [ABSTRACT FROM AUTHOR]

• CN pcf promotes the majority of coarse aggregates to form a well-embedded skeleton. • Optimum contents of dominant structure and disturbing aggregates were determined. • Correlation of CN pcf with contact zones (CZ) can describe internal structural features. • Mann-Whitney U test verified stability of the dominant skeleton with the appropriate level of CN pcf for resisting permanent rutting. Optimizing asphalt mix design at the indoor stage is of significant importance for enhancing the rutting resistance of asphalt mixture, which is affected by its structural characteristics. In this work, the coordination number of particle contact force (CN pcf) was proposed as an indicator to represent contact characteristics of skeleton structure aggregates in asphalt mixture. Nine asphalt mixtures with different gradations were designed, and the relationship of CN pcf with the number of aggregate contact zones (CZ) was established by combining rutting tests and digital image processing technique (DIP). The Mann-Whitney U test was implemented to analyze the distribution properties of inter-particle contacts before and after the rutting test. In addition, the resistance to the further expansion of rutting was analyzed. The results revealed a significant positive correlation (PCCs = 0.843, R 2 = 0.711) between CN pcf and CZ. The content of coarse aggregates in the dominant structure did not exhibit monotonic related to anti-rutting performance of the asphalt mixture. Therefore, an optimum aggregate content of 57% was utilized. The Mann-Whitney U test revealed that the mesoscale skeleton structure of the asphalt mixes before and after rutting exhibited excellent stability. This study further indicated the applicability of combining CN pcf to adjust the mix design to enhance the rutting resistance of asphalt mixture and to prevent rutting expansion in flexible pavement. [ABSTRACT FROM AUTHOR]

A novel electrochemical biomimetic sensor for theophylline detection was proposed, which was based on the molecular recognition events with artificial receptors, followed by triggering the surface initiated polymerization (SI-ATRP) to amplify the signals. Electropolymerized molecularly imprinted polymer (E-MIP) using thiophene-3-acetic acid (3-ATT) as functional monomers and theophylline as templates was employed to generate molecular recognition sites and led to immobilization of initiator-conjugated theophylline on the electrode surface. SI-ATRP subsequently was triggered and the polymer growth was monitored directly by atomic force microscope (AFM) technology. Acrylamide (AM) as growing chain units which accumulated in situ provided excess amino groups for the attachment of electrochemical tag, Phenothiazine sodium sulfonate (PTZ-343), thus enhanced assay sensitivity. The developed sensor displaying the excellent electrochemical detection performance that has a detection limit of 1.1 × 10−11 M for the dynamic range of 0.3 × 10−10 to 0.3 × 10−4 M. Notedly, compared to those sensors based on nature recognition events triggering polymerization-assisted amplification, the promising method has the advantages of low cost and good robustness. [ABSTRACT FROM AUTHOR]

• Early hydration kinetics model of IC materials with different absorption behavior was studied. • Effect of IC materials on microstructure and hydration products of cement paste was investigated. • The hydration degree and rate of cement can be promoted by increasing the dosage of composite microgel. • Hydration characteristics are in good agreement with the hydration kinetic model. Internal curing with superabsorbent polymer (SAP) has potential effect on the early deformation and hydration of cementitious material. However, there are few studies on the hydration kinetics and hydration characteristics of internal curing cementitious material. Here, the effects of microgel, composite microgel and commercial SAP with different dosage and absorption behaviors on the hydration characteristics of cement paste were studied by the hydration model proposed by Krstulović-Dabić and hydration heat. Results showed that the hydration reaction of paste containing internal curing materials increased as function of the dosage. When nano-silica(NS) incorporated into microgel, 24.5% and 5.6% increase in value of exothermic peak and cumulative heat were observed for paste. The hydration kinetic model showed that the composite microgel promoted the crystal growth and phase boundary reaction process, thus extending the transition point to the diffusion process. For commercial SAP with premature desorption behavior, the hydration rate of cement paste decreases and the appearance of conversion point at each process is delayed. Hydration characteristics are in good agreement with the kinetic model, suggesting that portlandite consumed by pozzolanic reaction promoted the development of hydration reaction and further refined the microstructure of paste. [ABSTRACT FROM AUTHOR]

[Display omitted] • (Co 0.2 Cu 0.2 Mg 0.2 Ni 0.2 Zn 0.2)O high entropy oxide were prepared via a solution combustion method. • The high entropy oxide exhibited a porous structure. • The high entropy oxide displayed excellent peroxymonosulfate activation for tetracycline degradation. The porous (Co 0.2 Cu 0.2 Mg 0.2 Ni 0.2 Zn 0.2)O high entropy oxide was synthesized by a facile solution combustion method. The X-ray diffraction (XRD) patterns showed that a rock-salt phase (Co 0.2 Cu 0.2 Mg 0.2 Ni 0.2 Zn 0.2)O nanocrystalline was successfully constructed after heat treatment above 800 °C. A porous microstructure with high specific surface area was determined by scanning electron microscope (SEM) and N 2 adsorption analysis, respectively. The (Co 0.2 Cu 0.2 Mg 0.2 Ni 0.2 Zn 0.2)O high entropy oxide displayed excellent peroxymonosulfate (PMS) activation which could fully degrade the tetracycline (TC) within 24 min. Moreover, the effect of PMS concentration, the high entropy oxide dosage, pH value, temperature and coexisting anions on the degradation efficiency of TC was systematically studied. According to free radical quenching experiments and electron paramagnetic resonance studies, the possible mechanism of TC degradation over the (Co 0.2 Cu 0.2 Mg 0.2 Ni 0.2 Zn 0.2)O/PMS system was proposed. This work provided a research basis for the use of high entropy oxide for PMS activation in environmental treatment. [ABSTRACT FROM AUTHOR]

• 5 kinds of WAL for steel bridge pavement have been prepared based on self-stratification behavior between the acrylic resin and epoxy resin. • WAL demonstrates excellent adhesive strength, mechanical performance, impermeability and UV durability. • The self-stratification mechanism was discussed based on surface energy theory and micro characterization. In view of the shortcomings of the existing steel bridge deck waterproof adhesive layer (WAL), such as poor durability, high construction cost and long construction period, a new preparation method of waterproof coating with self-stratification effect is proposed. In this paper, poly butyl acrylate-methyl methacrylate–styrene block copolymer with lower glass transition temperature was synthesized by free radical solution polymerization, and 5 kinds of self-stratification coatings were obtained by mixing it with epoxy resin at different mass ratios. The glass transition temperature, thermal stability and chemical composition of acrylic resin were characterized by DSC, TGA, and FT-IR. The self-stratification behavior of the coatings was confirmed by FT-IR, SEM, and water contact angle test. The basic performance and road performance of above self-stratifying waterproof coatings were tested according to specific standards. The results show that these coatings exhibit excellent heat resistance, low temperature flexibility and mechanical properties, namely, average tensile strength can reach 6 MPa, the elongation at break can reach 108 %. Furthermore, the coatings also present extraordinary pull-out strength of 9.51 MPa and excellent water impermeability. Moreover, the tensile strength and elongation at break of the self-stratifying waterproof coatings after UV aging test decreased by 7.3 % and 5.2 %, respectively, indicating that above coating have excellent durability. Therefore, the performance of the coating prepared in this paper fully meets the requirements of the road and bridge waterproof coating standards. The optimum mixing ratio of acrylic resin and epoxy resin is recommended as 3:7 based on their performance. Finally, self-stratifying mechanism of coatings was proposed based on the surface energy theory, which provides theoretical support for the design and preparation of the steel bridge deck WAL. [ABSTRACT FROM AUTHOR]

• The internal meso structure of AC compacted using six different compaction methods was analyzed. • The distribution characteristics of asphalt binder and aggregate of compacted AC by six different compaction methods were obtained. • The relationship between aggregate contact points, aggregate freedom degree and mechanical performance of AC was established. • The AC compacted by roller and SGC in the laboratory could effectively simulate the compaction state on site. The difference between asphalt concrete (AC) compacted in the laboratory and the field significantly influences its gradation design and performance evaluation accuracy. In this research, the effect of the laboratory compaction and field compaction on AC characteristics were compared using the characteristic indexes of surface texture, internal structure, asphalt binder distribution, aggregate distribution, compressive resilience modulus, and the crack resistance index (CRI). Six different compaction methods for AC specimens were studied, and five different types of laboratory compaction equipment were used, namely the Marshall compactor, Steel segmented roller compactor (SSRC), Superpave gyratory compactor (SGC), shear box compactor (SBC), and roller. The results showed that a uniform texture of AC surface was created with vibration and kneading. The aggregate contact distribution of specimens compacted by SGC, SBC, and roller was similar to field compaction as an inverse "bathtub" shape. The aggregate rotation angle of AC compacted by SGC, SBC, and roller showed higher randomness. The coarse aggregate of specimens degraded after Marshall compaction. The fine aggregate coated with more asphalt binder being moved towards the middle height of the specimen, resulting in higher asphalt binder content in the middle layer during the compaction of SGC and SBC. The specimens compacted with SGC and SBC had better mechanical properties, especially in the middle layer of the specimen. The increase of aggregate contact points improved the mechanical properties of the mixture. The free movement of aggregates was helpful for slippage of aggregates and promoted the filling of voids with asphalt mastic to make the skeleton structure more compact. Correlation analysis showed that SGC and the roller could better reproduce the field compaction state. [ABSTRACT FROM AUTHOR]

• PP fiber and nano-TiO 2 modification improves the road performances of PMM. • The optimum ratio of PP fiber and nano-TiO 2 in PMM has been determined. • The PMM showed excellent photocatalytic exhaust degradation capacity. • The PMM significantly reduces the energy consumption and greenhouse gas emissions. To purify severe air pollution in traffic-intensive urban areas and tunnels, an innovative type of photocatalytic micro-surfacing mixture (PMM) was designed, which was enhanced by polypropylene (PP) fiber and nano-TiO 2. In this work, the road performance of sixteen PMMs with the different contents of PP and nano-TiO 2 were evaluated by wet-track abrasion test, wheel rutting deformation test and low-temperature splitting test. The vehicle exhaust (VE) gas degradation capacity of sixteen PMMs was characterized under ultraviolet (UV) light and visible light conditions. The life cycle assessment (LCA) methodology was applied to evaluate the environmental impact of PMM. The results showed that the road performances of PMM were improved with the increase of the PP fibers amount. The VE gas degradation capacity was significantly enhanced with the increase of nano-TiO 2 amount. PMM with 0.2 wt% PP fibers and 60 wt% replacement of mineral filler with nano-TiO 2 was a viable alternative to improve photocatalytic degradation of VE in pavement engineering. In addition, the modified micro-surfacing mixture facilitates a significant reduction in energy consumption and greenhouse gas emissions. [ABSTRACT FROM AUTHOR]

[Display omitted] • A self-cleaning synergistic photocatalytic superamphiphobic coating. • The inhibition of NO 2 production during the NO photocatalytic degradation process. • Synergistic effect of self-cleaning and photocatalysis of photocatalytic coating. • A green NO photocatalytic degradation mechanism of photocatalytic coating. Multitudinous deleterious NO 2 will be produced in the process of NO photocatalytic degradation, which may cause serious secondary pollution. In this study, a self-cleaning synergistic photocatalytic coating was constructed by the simple spray method. The coating has excellent superamphiphobicity and NO degradation performance. In addition, the production of NO 2 in the process of NO degradation by photocatalytic superamphiphobic coating was inhibited, which indicated the greener photocatalytic process exhibited by this photocatalytic coating. Also, to clarify the inhibition of the coating on NO 2 , the NO degradation mechanism of the coating and photocatalyst was investigated by in situ IR, trapping test and EPR spectra, and the possible pathway of NO degradation was summarized. Combining the result of DFT calculation and degradation product analysis, the inhibition of NO 2 and"green" degradation mechanism of the self-cleaning synergistic photocatalytic coating was explored and proposed, which may provide some theoretical support for the "green" application of photocatalysis. [ABSTRACT FROM AUTHOR]

• EIS was used to study the diffusion of water vapor and oxygen in bitumen. • With the growth of duration, temperature and humidity, the impedance arc of bitumen gradually decreased in the Nyquist plot. • Temperature and humidity had a great influence on the diffusion coefficient of moisture and oxygen in bitumen. The moisture and oxygen in the air continue to diffuse to the bituminous pavement, causing moisture damage and water aging. In this paper, the electrochemical impedance spectroscopy (EIS) test was carried out through changing duration, temperature and humidity to determine the average diffusion coefficient of different bitumens. The results show that the increase of duration, temperature and humidity would cause the impedance arc of bitumen to shrink and the impedance modulus to decrease. The capacitance parameters obtained by fitting also increased significantly with duration, because the dielectric constant of bitumen and the polar groups caused by water aging increased with the continuous penetration of water vapor and oxygen possibly. Further, based on the Continuous model, temperature and humidity had a significant effect on the coupled diffusion coefficient of water vapor and oxygen in the bitumens. [ABSTRACT FROM AUTHOR]

[Display omitted] • g-C 3 N 4 nanosheets were prepared via a molten salts method. • Crystalline g-C 3 N 4 nanosheets was composed of triazine ring unit. • The g-C 3 N 4 nanosheets show the excellent photocatalytic activity for the degradation of RhB. The crystalline g-C 3 N 4 nanosheets have been successfully prepared by one-step molten salts method. The microstructures and optical properties of as-prepared samples were characterized by different techniques, such as XRD, EDS, XPS, SEM, TEM, BET, PL and Uv–vis DRS. The results showed that the unit of the crystalline g-C 3 N 4 nanosheets was composed of triazine ring, which was different from heptazine-based g-C 3 N 4. The crystalline g-C 3 N 4 nanosheets were thin and transparent, which were similar to graphene. The crystalline g-C 3 N 4 nanosheets exhibits the excellent photocatalytic activity, which can degrade 98% RhB within 120 min under visible light irradiation. However, the degradation efficiency of bulk g-C 3 N 4 is only 40% within 120 min. The enhanced photocatalytic activity of g-C 3 N 4 nanosheets can be attributed to 2D nanosheet morphology, which inhibits the electron-hole recombination. In addition, the high specific surface area of g-C 3 N 4 nanosheets positively increases the contact area with pollutants, making the degradation reaction more efficiently. A plausible photocatalytic mechanism was proposed for the degradation of RhB under visible light irradiation. [ABSTRACT FROM AUTHOR]

During the aging process, the desulfurization and degradation process of crumb rubber modified asphalt binders (CRMA) consistently occurs. In this paper, a toluene insoluble test, an electrochemical titration method, viscosity, FTIR and GPC were developed to determine the effective crumb rubber content of CRMA after exposure to various aging conditions. Centering on efficiency and accuracy, these five methods were compared with the Pearson coefficient method. The results show that when the degree of aging was severe, the desulfurization and degradation of rubber were aggravated, causing the C C bond in the rubber to break and an increase in the large molecular weight of the asphalt binder. The effective rubber content in the aged CRMA was 7.7–14.2% less than the unaged CRMA. At the same time, the correlation coefficients among the five methods were all above 0.90, but the electrochemical titration and FTIR had priority over the other methods. • Aging will accelerate the degradation of rubber in modified asphalt binder. • The effective rubber content using electrochemical titration and FTIR are quantitative evaluated. • GPC and mass methods have certain man-made errors. • The Pearson correlation coefficients of methods are all over 0.9. [ABSTRACT FROM AUTHOR]

• The freeze-thaw cycle caused the complex modulus of asphalt binders to decrease and the phase angle to increase. • The influence of freeze-thaw cycles on SBS modified asphalt binder was more obvious than that of base asphalt binder. • The creep recovery rate of SBS modified asphalt binder was reduced, opposite to that of base asphalt binder. Perennial freeze-thaw cycles have caused frequent disasters on asphalt pavements. To investigate the effect of four types of freeze-thaw cycles on asphalt binders, the DSR and FTIR test results of #70 Jinlin base asphalt binder (J binder) and SBS modified asphalt binder (S binder) were studied. The rutting factor, creep compliance and fatigue life of binders after freeze-thaw cycles were evaluated first, and then the chemical composition was analyzed. The results show that multiple freeze-thaw cycles lead to a growth in the complex modulus of asphalt binders, but the phase angle of S binder did not decrease significantly. The attenuation of fatigue life of S binder was significantly higher than that of J binder, and there was a certain dependency on fatigue parameters and freeze-thaw damage based on the S-VECD model. Furthermore, after the freeze-thaw cycle, the creep recovery of S binder decreased, while that of J binder increased, due to the increased elasticity by the oxidation of J binder. Carbonyl index (CI) and sulfoxide index (SI) of binders gradually grew with the number of freeze-thaw cycles, and butadiene index (BI) of S binder also slightly decreased. In general, during repeated freezing and thawing, low temperature had a certain adverse influence on the binders, but it is lower than that caused by high temperature. [ABSTRACT FROM AUTHOR]

Photocatalytic coating has been widely studied as a promising material to remove air pollutants. However, the effectiveness and long-term effect of photocatalysis in high relative humidity environment is still the main challenge in this field. In this study, a fluorinated WO 3 -TiO 2 nanorods/SiO 2 epoxy photocatalytic superamphiphobic coating (FTSE coating) was prepared using a simple spraying method. The micromorphology and chemical composition of FTSE coating was characterized by SEM, EDS, FT-IR, XPS and TGA techniques. The advanced contact angle and hysteresis angle test show that the FTSE coating had excellent superamphiphobicity. The mechanical abrasions, corrosion resistance and UV aging tests show that the FTSE coating exhibited reasonable durability. Besides, the NO degradation efficiency of hydrophilic and superamphiphobic coatings with contact angles of 20.19°, 87.74°, 162.93° and 164.47° was tested in different humidity environment. The results showed that the superamphiphobic coating exhibited more superior photocatalytic degradation efficiency (84.02%) than the hydrophilic coating (51.38%) at a high relative humidity (RH=98%). Finally, FTSE coating exhibited prominent photocatalytic stability and the synergistic effect of photocatalysis and self-cleaning. After 30 d outdoor weathering test, the NO degradation efficiency decreased by 13.07% and recovered to the original level after flushing. The improvement mechanism of NO degradation performance was proposed based on the characteristics of superamphiphobic surface. [Display omitted] • A WO 3 -TiO 2 nanorods/SiO 2 photocatalytic superamphiphobic coating. • The reasonable robustness and excellent superamphiphobicity. • The prominent degradation performance in high relative humidity environment. • A mechanism of improving the NO degradation efficiency. [ABSTRACT FROM AUTHOR]

The utilization of processed waste materials in road construction is of utmost significance from the environmental and economic viewpoints. In this paper, waste cooking oil (WCO) and ground tire rubber (GTR) were applied to modify the asphalt binder. Based on the optimal content of both modifiers, sixteen asphalt samples with different combinations of the two wastes were designed. Relevant tests including basic properties along with rheological behavior and chemical characterization were carried out on the modified asphalt. The results indicated that the modified asphalt with 20 wt % GTR and 2.5 wt %-5 wt. % WCO exhibited satisfactory high temperature resistance and low temperature rheological properties. The Fourier transform infrared spectroscopic investigation revealed that the presence of GTR increased the concentration of styrene and butadiene while the addition of WCO introduced fatty acids and esters to modified asphalt. Overall, the road performance studies demonstrate that modified asphalt mixture with 5 wt % WCO and 20 wt % GTR displayed a markedly improved anti-rutting properties, water stability and superior low-temperature performance compared to normal asphalt mixture. • The molecular structures of WTO/GTR-modified asphalt were analyzed. • Asphalt modified with an appropriate amount of GTR and WCO exhibited optimum properties. • GTR increased the concentration of functional groups in modified asphalt binder. • WCO introduced fatty acids and esters to modified asphalt binder. • WTO/GTR-modified asphalt mixtures showed a promising application in road industry. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel kind of microgel has been synthesized by inverse suspension polymerization. • The microgel showed a desired absorption and water retention in cement filtrate. • The drying shrinkage and compressive strength of modified mortar were improved. In this paper, three kinds of P(AM- co -MAA) microgels with different anion contents were synthesized by inverse suspension polymerization with acrylamide (AM) and methacrylic acid (MAA). The modified mortar was prepared by cement and sand as fillers and P(AM- co -MAA) as internal curing agent. The swelling behavior of P(AM- co -MAA) microgels with different anion contents in aqueous solutions was studied. The effects of P(AM- co -MAA) and commercial superabsorbent polymer (SAP) on the flowability, mechanical properties, drying shrinkage and microstructure of mortar were investigated. The results showed that the presence of multivalent cations (mainly Ca2+) weakened the absorption capacity of microgels in cement filtrate. Spherical microgels had no negative effects on the flowability and mechanical properties of cementitious materials. The compressive strength of modified mortar can be significantly improved at later curing stage due to dome structure and internal curing. Furthermore, the water content of modified mortar with 0.1% additions of microgel decreased, and the drying shrinkage rate of the modified mortar was about 36% lower than that of cement mortar without microgels. It can also be observed that a large amount of macro pores were not formed around the microgels. [ABSTRACT FROM AUTHOR]