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Nano zero-valent iron (nZVI) has high catalytic activity for nitrate electroreduction, however, it is easy to aggregate due to the nature magnetic properties. Herein we choose coconut activated carbon(AC) as the supporter to disperse the nanoparticles. Coconut AC primarily consists of a large number of micropores and mesopores. The micropores mainly provide large surface area to adsorption the nitrate ions first, and mesopores are responsible for the supporting nZVI particles. The adsorbed nitrate can migrate easily to the nZVI sites for reduction reaction. The aim of this paper is to determine the maximum nZVI loading capacity on AC without agglomeration, and also their corresponding activity for the electroreduction of nitrate to ammonia. The morphology and structural characteristics of the electrodes showed that nZVI can be evenly distributed on AC when the loading lower than 40 wt%, and the highest. NH3Faradic efficiency of 97.2 % was obtained with nZVI40@AC at −7.5 mA/cm2. In addition, to clarify the sensitivity of the operating parameters the nitrated reduction. Response surface area was applied to evaluate the interactive effect between the operating parameters.

ABSTRACT In this paper, the recovered waste packaging ethylene-vinyl acetate copolymer (EVA) and crumb rubber (CR) were used as polymer modifying agents to prepare EVA/CR modified asphalt, and the EVA/CR [...]

ABSTRACT Isocyanate modified asphalt samples were got by adding quantitative isocyanate into the base asphalt. Isocyanate and nano particles composite modified asphalt samples were produced by adding quantitative isocyanate and [...]

ABSTRACT An analysis of waste polyethylene (WPE) modified bitumens prepared using a variety of approaches is described in this study. The WPE was obtained from commercially-available packaging bags. It has [...]

• PCs prepared by bottom-up self-assembly method have the advantages of low cost, easy processability and large production batch. • In this review, we attempt to summarize the novel colloidal building blocks and their synthesis methods. • The latest bottom-up self-assembly methods and their applications are discussed. • Photonic crystals (PCs) show great potential for new sensors, anti-counterfeiting inks, displays, smart glass, textiles. Inspired by special color-forming organisms in nature, photonic crystal materials with structural color function have been developed significantly with great potential applications for displays, sensors, anti-counterfeiting inks, etc. This review aims to summarize the functions, self-assembly modes, and applications of different kinds of photonic crystal materials. The preparation methods and characteristics of monodisperse inorganic nanoparticles, polymer nanoparticles, inorganic/organic core-shell nanoparticles, and MOFs are discussed. Subsequently, we summarize the method of assembling colloidal particles into photonic crystals, which is a template induction method, inkjet printing method, drop coating method, etc. Moreover, the potential application of structural color is presented including humidity response and magnetic field response in sensors fields, as well as the advantages and disadvantages of anti-counterfeiting, fabric coloring, displays, smart windows, and Biomedical Applications. Finally, we present the development prospects and key problems of photonic crystals. [ABSTRACT FROM AUTHOR]

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Thermochromic behaviors of VO2(M) are affected significantly by the size purity, and crystallinity of the particles, and it needs a mass of experiments to adjust the factors suitably. Herein, an orthogonal array design (OAD) [L9(34)] was applied to select the optimum conditions for high-throughput preparation of VO2(M) nanoparticles with controllable morphology and size. The effects of fill ratio, reaction time, annealing time, and annealing temperature on the size of VO2(M) nanoparticles were evaluated by OAD. These results showed that the factors for the size arranged as follows: fill ratio > reaction time > annealing time > annealing temperature. The validation of optimized experimental parameters proved that pure VO2(M) nanoparticles with a diameter of ∼60 nm were prepared in this work. Therefore, the high-throughput preparation of VO2(M) nanoparticles with small size was achieved via an optimized two-step hydrothermal synthesis method, which can support the large-scale applications of VO2(M) nanoparticles in smart windows and optical switches.

Rare earth Tb3+doped (K0.465Na0.465Li0.07)(Nb0.93Bi0.07)O3(KNNLB-x%Tb) lead-free transparent ferroelectric ceramics were designed and prepared. The effects of Tb3+on phase structure, microstructure, optical transmittance, photoluminescence, and photochromic behaviors were studied. Although two ferroelectric phases coexist, the optical transmittance can reach the high value of 74% in the visible light region because of the fine grains, dense ceramic microstructure, large optical energy band gap, and relatively high symmetry of coexisting ferroelectric phases. In addition, Tb3+works as a luminescent center, and the reversible photochromic modulation is achieved by alternate stimulation of illumination and heat treatment. Meanwhile, the luminescence contrast can be improved under in situelectric field stimulation due to the easy change of lattice symmetry in coexisting ferroelectric phases. The generation of color centers after illumination and the local crystal field around the luminescent center caused by in situelectric field contributes to above phenomena. These ceramics exhibit the great potential in optical data storage and anticounterfeiting.

• Oxidized rigid carbon foam (ORCF) with high porosity and open cell is prepared. • The ORCF possesses a fluffy and porous surface with rich O-containing groups. • The ORCF has a hierarchical macro-nanoporous structure with mesoporous nature. • High adsorption capacities and partition coefficients for MG and Pb2+ are achieved. • The ORCF is an efficient adsorbent with good cycling stability for MG and Pb2+. This study developed a method to fabricate a surface-oxidized rigid carbon foam (ORCF) with hierarchical macro-nanoporous structure via KOH activation of the carbon foam with two kinds of macropores followed by HNO 3 hydrothermal oxidation. The structures of the prepared ORCF were characterized using scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared (FTIR) spectra, X-ray photoelectron spectroscopy, and N 2 adsorption-desorption analyzer. Results demonstrate that the ORCF possesses a fluffy and porous structure with rich oxygen-containing groups. There are numerous through-holes on its pore surfaces connected with two-level macropores forming hierarchical macroporous channels. Meanwhile, the ORCF remains a good bulk structure with a compression strength of 0.74 MPa at a bulk density of 0.09 g cm−3. Batch adsorption experiments for malachite green (MG) and Pb2+ were studied through the single variable method to investigate the effects of different initial conditions on its adsorption process. The ORCF has maximum adsorption capacities for MG and Pb2+ of 587.68 mg g−1 and 157.80 mg g−1 with high partition coefficients of 17.41 mg g−1 µM−1 and 14.86 mg g−1 µM−1, respectively. The experimental data are suitable for Langmuir isotherm and Pseudo-second-order kinetic models, which correspond to monolayer chemisorption. Thermodynamic analysis indicates that the adsorption process is spontaneous and endothermic. Moreover, the removal percentages of MG and Pb2+ by the ORCF could remain above 90% after five cycles, implying that the ORCF is an efficient adsorbent with good adsorption ability and cycling stability. [Display omitted] [ABSTRACT FROM AUTHOR]

Waterborne polyurethane (WPU) and Ag NPs have been applied widely in packaging. However, WPU was susceptible to the contamination due to high moisture absorption, and the stability of Ag NPs in matrix polymers was still low. To resolve this problem, chitosan (CS) was used as the dispersant to synthesize CS/Ag NPs composites in this work, and then they were mixed with WPU to prepare CS/Ag-WPU films. CS macromolecules provided the carriers for Ag NPs with a diameter of about 2.5 nm, and Ag NPs were dispersed stably in WPU. Compared with pure WPU film, as-prepared CS/Ag-WPU films had a higher thermal stability at low temperature, and the crystal size for WPU increased after introducing CS/Ag NPs. Importantly, the water contact angle for CS/Ag-WPU-5 increased to 54.2° from 27.5° implying that the hydrophobicity was improved. In addition, CS/Ag-WPU composites exhibited an excellent inhibitory effect on Escherichia coli(E. coli) and Staphylococcus aureus(S. aureus). Antibacterial performances of most samples were improved with the crease of the concentration of CS, and the inhibitory effect on S. aureuswas preferred. Therefore, as-prepared CS/Ag-WPU films in this paper have a potential application in antibacterial packaging field.

A valid strategy to tailor the properties of polylactic acid for more extensive applications was introducing filler. In this work, basalt fiber assembled with in-situ SiO 2 nanoparticles on the surface was successfully prepared via hydrothermal method and it was further treated with coupling agent KH-550 to improve interfacial interaction between polylactic acid (PLA) and basalt fibers (BF). It was demonstrated that the introduction of BFS could increase the crystallization of PLA and resulted in forming trans-crystallization based on TG and DSC results. The tensile strength of PLA/BF composites raised from 39 MPa to 62.5 MPa with increasing the fiber loading from 1 wt% to 10 wt%. Furthermore, the interfacial interaction could be effectively improved by assembling SiO 2 (especially with 250 nm in diameter) on BF surface to build mechanical locking, which could keep the PLA matrix in place during the mechanical deformation with the tensile strength value raised from 62.5 MPa to 74.0 MPa. It is noticeable that the impact and flexural properties were effectively increased with the incorporation of in-situ SiO 2 nanoparticles. The further KH-550 treatment made a positive impact as well. For instance, the impact strength and flexural strength of the sample with SiO 2 and KH-550 modification were improved to 22.49 kJ/m2 and 146.83 MPa and it enhanced about 42.16% and 41.04% than those of neat PLA, respectively. Therefore, an efficient enhancement of mechanical performance was achieved and this concept of assembling in-situ SiO 2 on silica-based fiber as a modifier was a novel and simple path to design the interfacial construction and properties of the polymer composites. [ABSTRACT FROM AUTHOR]

To change the optical properties and improve the antibacterial performances of carbon quantum dots (CQDs) and Ag NPs, mesoporous SiO2spheres were combined with them to form the composites. In this paper, CQDs with a uniform size of about 3.74 nm were synthesized using glucose as carbon source. Then, CQDs/mesoporous SiO2/Ag NPs composites were obtained in situunder UV light irradiating by using mesoporous SiO2and Ag NO3as the carrier and silver resource, respectively. The diameter of CQDs/mesoporous SiO2/Ag NPs particles was in the range of 200–250 nm. With the increase in irradiating time, the red-shift in the UV-Vis spectrum for as-prepared CQDs/mesoporous SiO2/Ag NPs composites was found, and the adsorption peak was widened. In addition, the composites showed a high antibacterial activity against Staphylococcus aureusand Escherichia colivia disc diffusion method. These results indicated that inhibition circles for Ag NPs/mesoporous SiO2/CQDs and mesoporous SiO2/Ag NPs were similar in diameter. Furthermore, the two composites had a better bactericidal performance compared with other particles. Therefore, as-prepared CQDs/mesoporous SiO2/Ag NPs composites in this paper have great potential applications for fluorescent materials and antibacterial materials.

To meet the high-precision needs of conductive ink in the field of microelectronic circuit printing, nano silver-coated graphene oxide (GO) composites were prepared as the conductive functional unit of the composites. The results show that compatibility of the GO grafted with ethylene glycol diglycidyl ether is better in the organic matrix than in the inorganic solvents. The nano silver particles attached to the surface of the grafted GO are evenly distributed and uniform in size. Moreover, the conductivity of grafted GO coated with silver particle composites is effectively improved. The composite conductivity is higher than 108S/m, which is close to the electrical conductivity of silver.

Owing to the facile, low cost, rapid, personalization characters, 3D printing method has been one of the most attractive additive manufacturing processes in medicine, airplane, packaging and printing areas. In this work, a series of carbon nanotubes/polylactic acid (CNTs/PLA) composites were prepared through the combination of molten co-extrusion and 3D printing processes. The orientation and dispersion of CNTs in PLA matrix were investigated to explore the impact of 3D printing process on the morphology of CNTs/PLA composites via transmission electron microscopy, field emission scanning electron microscopy and Raman spectroscopy. X-ray diffractometer, differential scanning calorimetry, and thermal gravity analysis were employed to study the crystal structure and thermal properties of the composites. In addition, the electrical conductivity of the prepared specimen revealed that the orientation of CNTs in PLA might enhance the conductivity of the composite. It was found that 3D printing process was beneficial to increasing the purity of CNTs, electrical conductivity and mechanical properties of CNTs/PLA composites. [ABSTRACT FROM AUTHOR]

With the development of nanobiotechnology, the carbon nanotubes (CNTs) and protein hybrids system has attracted an increasing attention for great potential application in nanotechnology, medicine, smart materials, light industry, and biology. In this review, the main preparation processes, impact factors, measurement of interactions and potential applications of CNTs/protein are presented from the aspect of experiments. Meanwhile, the proper forces detection methods are illustrated comprehensively to complete the quantitative measurement. Atomic force microscope (AFM) and surface force apparatus (SFA) experiments are described in detail to confirm the powerful function in measuring the interaction forces. In addition, the impact of different protein structures (amino acid residues, α Helix, polypeptide chain, and assembled subunits) on interactions between CNTs and protein is presented and different amino acid residues may intervene largely on interactions. Owing to the relatively little knowledge about the structure, function, and spatial orientation of proteins interaction with CNTs surface, we assume that the key problem is how to prepare CNTs and protein specimen with unique structure (such as the variation of secondary and tridimensional structure of protein or the single CNTs) to investigate the interaction forces instead of the designed, preparation, and detection methods. [ABSTRACT FROM AUTHOR]

High-performance electrode materials derived from biomass for supercapacitors have been considered as an effective solution to the problems of the fossil energy shortage and the environment deterioration. Most importantly, the specific capacitance, rate performance and cyclic stability for these electrode materials are focused issues. Here, we prepare a new type porous carbon using laminaria japonica as the carbon source via a simple carbonization and activation method, and investigate its morphology, structure and electrochemical properties. The results show that the porous carbon materials exhibit amorphous structure, high specific surface area with abundant pores and oxygen functional groups. The specific capacitance of the porous carbon with a large specific surface area of 1902.42m2g−1and total pore volume of 1.26cm3g−1can reach to 192Fg−1at 0.1Ag−1. Furthermore, this porous carbon possesses a specific capacitance of 120Fg−1at 10Ag−1, nearly 100% capacitance retention rate and coulomb efficiency after 10000 cycles at 1Ag−1, indicating excellent rate performance and cyclic stability. Therefore, as-prepared porous carbons derived from laminaria japonica with low cost, easy availability, high regeneration ability and sustainability have a promising application as the electrode materials for supercapacitors.

The porous carbon/Fe3O4composites have been used to adsorb the dyes recently, however, most carbon sources are not preferable for the environment protection. In this paper, the porous carbon/Fe3O4composites were synthesized by a simple step carbonization method using the waste cigarette butts and the ferric nitrate as carbon source and oxidizer, respectively. Notably, the obtained products can be reused. The results show that the crystallite size of as-prepared Fe3O4will increase at high treating temperature. In addition, the sample of C-Fe3O4-1000 possesses the highest saturation magnetization of 92.2 emu g−1, and the sample of C-Fe3O4-600 has the highest specific surface area of 90.23 m2 g−1and the maximum adsorption of 102.04 mg g−1for methyl orange. Furthermore, the adsorbent can maintain an excellent adsorption capacity for the dye after 4 cycles. Therefore, as-prepared porous carbon/Fe3O4composite is an excellent candidate for recyclable dye adsorbent, and the waste can be converted into products for reducing the environment pollution.

Highly dispersed carbon microspheres (CMSs) derived from D-xylose were successfully synthesized under hydrothermal conditions and followed by further carbonization, in which F127 was used as a soft template. As-synthesized products were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), flourier transform infrared spectroscopy (FT-IR), thermal gravimetric (TG) and X-ray diffraction (XRD). The results showed that the morphology and structure of the CMSs prominently depended on the stirring speed during hydrothermal reaction. The resultant CMSs principally had non-porous structure without stirring and had a very smooth surface. When the stirring speed increased to 200 rpm, the synthesized mesoporous carbon microspheres at 220 °C for 24 h (CMSs-5) had a uniform size distribution of 1–1.4 μm and a specific surface area of 452 m2/g. Nevertheless, with further increasing to 400 rpm, as-fabricated carbon products were mostly amorphous with a low degree of sphericity. Results demonstrated that the diameter of the products decreased with the increase of stirring speed. Furthermore, the sphericity product yield of CMSs reduced with the increase of stirring speed. XRD result showed that all the obtained samples contained partial graphite phase. In addition, a formation mechanism was proposed that involved polymerization product as the precursors for microsphere formation. The controllable and green strategy may provide a great convenience to study properties and applications of carbon microspheres. [ABSTRACT FROM AUTHOR]

Uncured rubber possesses remarkable hyperelastic and viscoelastic properties while it undergoes large deformation; therefore, it has wide application prospects and attracts great research interests from academia and industry. In this paper, a nonlinear constitutive model with two parallel networks is developed to describe the mechanical response of uncured rubber. The constitutive model is incorporated with the Eying model to describe the hysteresis phenomenon and viscous flow criterion, and the hyperelastic properties under large deformation are captured by a non-Gaussian chain molecular network model. Based on the model, the mechanical behaviors of hyperelasticity, viscoelasticity and hysteresis under different strain rates are investigated. Furthermore, the constitutive model is employed to estimate uniaxial tensile, cyclic loading–unloading and multistep tensile relaxation mechanical behaviors of uncured rubber, and the prediction results show good agreement with the test data. The nonlinear mechanical constitutive model provides an efficient method for predicting the mechanical response of uncured rubber materials.

Highly stable Ag NPs were synthesized using anionic polyacrylamide (APAM) as the template and reductant. When APAM concentration was 1.50 µM, as-prepared Ag NPs with the diameter of about 3.8 nm had a quantum yield as high as 1.51%. When adding Cu2+and Hg2+into the Ag NPs solution, the fluorescence was quenched effectively. The response between the fluorescence intensity and metal ions concentration allowed for a linear relation, and the detecting limitation for Cu2+was lower than 1 × 10−9mol/L.Highly stable Ag NPs were synthesized using APAM as the template and the reductant. When the APAM concentration was 1.50 µM, the size of Ag NPs was about 3.8 nm and the quantum yield reached 1.51%. The fluorescence was quenched by Cu2+and Hg2+effectively. The detecting limitation for Cu2+was lower than 1 × 10−9mol/L.

A synthesis strategy of fluorescent carbon quantum dots (CQDs) with high quantum yield (QY) using aqua mesophase pitch (AMP) as the carbon source has been developed via the hydrothermal method in this study. The hydrothermal temperature and soaking time have important effects on the morphology and QY of CQDs. As-prepared CQDs at 120 °C holding for 24 h (CQDs-120-24) have the uniform size of about 2.8 nm, and the QY can reach 27.6%. The obtained CQDs are successfully modified with ammonia and thionyl chloride, respectively, and they exhibit an excellent photocatalytic performance on degrading rhodamine B (Rh B), methyl blue (MB) and indigo carmine (IC). Importantly, the degradation percentage of N-CQDs on Rh B under natural light for 4 h reaches 97% with the degradation rate constant of 0.02463 min−1 and it can maintain 93% after repetitively used 5 times. The results indicate that these as-prepared CQDs have the potential application in degrading organic dyes. [ABSTRACT FROM AUTHOR]

Waterborne polyurethane (WPU) dispersions have gained attention towards environmentally-friendly synthesis. In this article, a series of waterborne polyurethane emulsions was successfully synthesized and extensively characterized in terms of thermal, mechanical properties, hydrophilic behavior and morphology. Snow was chosen as dispersant instead of commonly used water. Preparation parameters such as intrinsic properties and molecular weight of polyols were discussed systematically. A chain structure was confirmed by Fourier transform infrared (FT-IR) spectroscopy. When comparing the nature of the polyols (PPG, PEG and PNA, 2000 g/mol) of this study, as-synthesized polyether waterborne polyurethane provided higher solid content, viscosity and water-resistance. However, polyester waterborne polyurethane performed differently and it exhibited higher thermal stability and crystallinity. When comparing the samples (WPU-N210, WPU-N220, WPU-N230 and WPU-N240) with different molecular weight of the same polyol (PPG) used as soft segment, the emulsion WPU-N220 with molecular weight of 2000 g/mol PPG provided the highest solid content and lowest viscosity. It was observed that particle size was uniform and highly dispersed for all samples from TEM images. Thermogravimetric, differential scanning calorimetry (DSC) and X-ray diffraction results demonstrated that the emulsion WPU-N230 with molecular weight of 3000 g/mol PPG possessed higher thermal stability and crystallinity than the other samples. The reason was that the T g and thermal stability were increased with increasing molecular weight. When molecular weight increased, the arrangement of soft segment became more regular and so did the regularity of the molecular chains. This work demonstrated that different polyols as soft segment applied could lead to great differences in the structure and property of the resulting WPU. [ABSTRACT FROM AUTHOR]

Abstract In this work, waste-styrene-butadiene-rubber (WSBR) -modified petroleum- based mesophase asphalt was prepared through a co-carbonization process. The influence of contents of WSBR and carbonization temperature on the properties of mesophase asphalt was investigated. The chemical constituents, microstructure and thermal property of the samples were characterized. The results show that using WSBR as modifier can significantly promote the formation of mesophase. When the temperature is constant, the addition of WSBR results in more optically anisotropic crystal structure in the samples, and a better thermal stability. When the content of WSBR is invariable, with increasing temperature, the content of anisotropic structure in mesophase asphalt becomes higher and more uniform. The thermal stability of the samples is the best when WSBR content is 10 wt%. [ABSTRACT FROM AUTHOR]

Abstract A series of supported iron oxide nanoparticles were prepared by impregnation with Fe(NO 3) 3 supported on TiO 2, followed by low-temperature calcination. Scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV–vis diffuse reflectance spectra and BET have been used to characterize the samples. These iron oxide-impregnated TiO 2 were examined for photocatalytic reduction of Cr(VI). The experiments demonstrated that Cr(VI) in aqueous solution was more efficiently reduced using Fe 2 O 3 /TiO 2 heterogeneous photocatalysts than either pure Fe 2 O 3 or TiO 2 under visible light irradiation. All TiO 2 supported samples were somewhat active for visible light photoreduction. With an optimal mole ratio of 0.05-Fe/Ti, the highest rate of Cr(VI) reduction was achieved under the experimental conditions. We also compared the photoreactivity of TiO 2 supported iron oxide samples with that supported on Al 2 O 3 and ZrO 2. It can be noted that iron oxide nanoparticles deposited on high surface area supports to increase the solid-liquid contact area renders it considerably more active. Noticeably, iron oxide cluster size and dispersion are important parameters in synthesizing active, supported Iron oxide nanoparticles. In addition, the interaction between iron oxide and TiO 2 was proposed as the source of photoactivity for Cr(VI) reduction. [ABSTRACT FROM AUTHOR]

Flexible sensors are promising for intelligent packaging and artificial intelligence, but the required multistimulus response is still a challenge in external environments. A candidate material for such multistimulus response is VO2due to its unique semiconducting properties. Herein, W-doped VO2(M) with a tunable phase transition temperature was prepared by the hydrothermal method, and then, VO2(M)-based flexible sensors were fabricated employing a direct-write strategy, where conductive inks with VO2(M) powders were patterned onto various substrates. These sensors achieve dual responses to temperature and strain and exhibit high stability (over 2000 stretch–release cycles) to accurately monitor various statuses (opening and closing, temperature changes, etc.) of intelligent packaging. The spatial pressure distribution of different objects was discerned by the prepared VO2(M)/poly(dimethylsiloxane) (PDMS) sponge flexible pressure sensor arrays, and the information was successfully edited using the Morse code. The sensing signals from the intelligent packaging were collected and remotely transmitted to intelligent terminals via a wireless local-area network to achieve real-time monitoring of the packaged contents. Therefore, in this work, we not only designed new flexible sensors with multiple stimulus responses but also demonstrated the potential applications of W-doped VO2(M)-based flexible sensors in intelligent packaging.

The N-doped porous carbon materials were prepared via the co-carbonization of cellulose acetate fiber and urea. The cellulose acetate fiber was derived from waste cigarette and urea was used as the nitrogen source and the activating agent. The carbonization temperature has an important effect on the specific surface area, porosity and nitrogen content of as-prepared porous carbon materials. When the carbonization temperature was 750degC, as-prepared CN-750 with an average pore size of 4.84 nm exhibited the highest specific surface area of 734 m2*g[?]1. The sample of CN-600 synthesized at 600degC showed the highest nitrogen content of 11.69 at%. Moreover, as-prepared samples with disordered pores showed a low graphitization degree and a large interlayer space. The specific capacitance of CN-750 is 152 F*g[?]1 at the current density of 1 A*g[?]1, which is higher than that of CN-600 and CN-900. After 5000 cycles, the capacitance retention of CN-600, CN-750 and CN-900 is 91.9%, 93.1% and 95.1%, respectively. The energy density of CN-750 is 5.28 Wh*kg[?]1 at the power density of 250.1 W*kg[?]1 and it retains 6.09 Wh*kg[?]1 at the power density of 24.97 W*kg[?]1. Our study indicates that the waste cigarette butts can be effectively recycled via the co-carbonization method, and as-prepared N-doped porous carbon materials with an excellent cycling stability and a reasonable availability are promising candidates for the electrode materials of supercapacitors.

Abstract Thermochromic material is a kind of smart material whose color will vary as the result of the phase transition caused by the temperature change. The characteristics of thermochromic materials are the memory functions to the temperature, having great potential applications in aerospace, military, anti-counterfeiting technology, construction and other fields. In recent years, many kinds of thermochromic materials have been prepared by different methods and their discoloration mechanisms are various according to published literatures. In this paper, the classification, discoloration mechanism, preparation methods, application fields and development trend of thermochromic materials are reviewed. [ABSTRACT FROM AUTHOR]

Fluorescent pigments, based on the optical or electrooptical properties of dyes, are the main component in fluorescent coatings and inks. In this study, three kinds of dyes (Rhodamine B, Light Green SF Yellowish, Coumarin) with four different ratios (2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%) were employed as luminophor, and the melamine-formaldehyde (MF) resin was used as curing resin to prepare fluorescent pigments in different color. Fourier transform infrared spectroscopy and X-ray diffractometry were carried out to analyze the structure of the fluorescent pigments. Scanning electron microscopy and particle size distribution were used to present the morphology of fluorescent pigments. UV–vis and fluorescence spectrum were used to demonstrate the optical properties. It can be concluded that, coumarin pigments possessed consecutive structure in MF resin while rhodamine B might be the best for the preparation of printing inks among the three kinds of dyes from the view of particle size. The TG results presented that all the pigments showed good thermal stability, which might possess potential application in high speed printing industry. [ABSTRACT FROM AUTHOR]

Multi-walled carbon nanotubes (CNTs) were modified by an amination treatment with hexamethylenediamine (HMD), and then bismaleimide (BMI)/epoxy (E-44)/CNTs ternary composites were prepared using modified CNTs as the reinforcement via a simple mixing and curing molding method. The results show that the surfaces of CNTs are grafted polymer with the thickness of 3 nm and the dispersity of surface grafted carbon nanotubes (SG-CNTs) in the resin composites can be improved. The prepared composites contain C C, C N, C O and −COOH groups and can keep a smooth surface. In addition, the composites have the flexural strength of 152 MPa, the tensile strength of 73 MPa and the impact strength of 87 kJ m −2 , respectively, when the weight ratio of BMI to E-44 is 1:8 and the content of SG-CNTs is 2 wt%. However, the thermal stability of the composites with SG-CNTs is a little lower than that of the composites without SG-CNTs. [ABSTRACT FROM AUTHOR]

A simple hydrothermal approach is used to prepare water-soluble carbon quantum dots (W-CQDs) by using glucose as the precursor and PEO106PPO70PEO106(F127) as the controlling agent. The homogeneous W-CQDs have an average size of 2.6 nm and show well dispersibility. W-CQDs/mesoporous SiO2composites are synthesized by using mesoporous SiO2as the carrier. The as-synthesized composites are characterized by SEM, TEM, XRD, and fluorescence spectrometry. The fluorescence intensity and quantum yield of the composite are higher than those of W-CQDs.A simple hydrothermal approach is used to prepare water-soluble carbon quantum dots (W-CQDs) by using glucose as the precursor and PEO106PPO70PEO106(F127) as the controlling agent. W-CQDs/mesoporous SiO2composites are synthesized by using mesoporous SiO2as the carrier. The fluorescence intensity and quantum yield of the composite are higher than those of W-CQDs.

Carbon nanotubes (CNTs) have been successfully grown on the surfaces of mesocarbon microbeads (MCMB) via a chemical vapor deposition (CVD) method by using iron particles as the catalyst. The morphologies of the hybrids were modulated by controlling the ratio (r) of H2 to C2H2. The obtained CNTs are uniform with an average diameter of 20 nm when r = 2 at 750degC. The specific surface area of such MCMB-CNTs-2 is 34.5 m2*g[?]1, and the specific capacitance is 319 F*g[?]1 at the current density of 1 A*g[?]1. More importantly, MCMB-CNTs-2 exhibits extraordinary cycling life stability (the retention is 88.4% after 5000 cycles), despite some CNTs may break off from MCMB surface after cycles. We attribute the improvement of electrochemical properties to the mesoporous structure and excellent electrical conductivity of the hybrids with low specific surface area. Our study indicates that the MCMB/CNTs hybrids are promising candidates for the electrode materials of supercapacitors.

Anionomer-type waterborne polyurethane dispersions (PUDs) were obtained from poly (propylene glycol) (PPG), isophorone diisocyanate (IPDI) and dimethylolpropionic acid (DMPA) through a modified prepolymer isocyanate process. Two series of polyurethanes were prepared (Groups A and B) and a new prediction model based on grey relational analysis is introduced to predict the impact order of raw materials on several properties, such as solids content, viscosity, acid number and electrolytic stability of polyurethanes. It is found that the model can successfully predict the impact of raw materials on the properties through the designed demonstration experiments. Furthermore, the results of the prediction model show that DMPA plays a key role in viscosity, partial acid values and electrolytic stability. [ABSTRACT FROM AUTHOR]

The low-cost petroleum pitch and waste polyethylene (WPE) were used as raw materials to prepare the mesophase pitch by co-carbonization method and the forming mechanization of mesophase pitch was also investigated. Polarized microscopy, softening point, Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) were used to characterize and analyze the properties and structure of the mesophase pitch. The results showed that the carbonization yield of the modified pitch was high when 1–2 wt% WPE was added and the property of mesophase pitch (MP1-450-4 and MP2-450-4) prepared by thermal polymerization was excellent. Moreover, when the treatment temperature was above 420 °C, the mesophase development of the modified pitch may be entire and 100% streamline texture mesophase can form. During the co-carbonization of WPE/petroleum pitch, a large number of naphthenic structures and methylene bridges may be generated, which can improve the properties of the obtained mesophase pitch. [ABSTRACT FROM AUTHOR]

Over the last few years, waterborne polyurethane (WPU) was applied to various fibers, adhesives, primers for metals, caulking materials, emulsion polymerization media, paint additives, defoamers, associate thickeners, pigment pastes, textile dyes and biomaterials, resulting in the increasing enthusiasm of researchers to design and synthesize novel WPU with unique properties. Thus, various processes and raw materials have been developed to prepare WPU. This review gives an overview on the developments of WPU mainly derived from novel polyols, analyzes the potential application in water-based inks and presents the probable future research area about water-based inks. Notably, the poly(ε-caprolactone) and poly(lactic acid) are the versatile materials used in WPU synthesis and supply the potential special performance for preparing WPU. Meanwhile, addition–fragmentation chain transfer (RAFT) polymerization and atom transfer radical polymerization (ATRP) processes provide an opportunity to control the chain sequence of WPU and obtain products with the desired performance. [ABSTRACT FROM AUTHOR]

In this study, waste polyethylene (WPE) was used as a modifier for base asphalt. In our previous studies, we have examined a variety of polymer modifiers for asphalt. By contrast, little research has focused on the preparation process, such as preparation time, preparation temperature and shear rate. The effect of preparation temperature on aging properties of WPE-modified asphalt was investigated in this work. The experimental materials were characterized by infrared spectroscopy (IR), thermo-gravimetric analysis (TG), and differential scanning calorimetry (DSC). The physical properties were determined by conducting asphalt penetration, softening point and ductility tests. The results show that increasing the preparation temperature results in an increased softening point of WPE-modified asphalt while decreased penetration and ductility. In addition, this variation was accentuated by aging the experimental materials. The modification process of WPE is a physical process. During the asphalt modification process, the WPE aged as the preparation temperature increased. The results revealed that 190 °C is the most suitable preparation temperature, and the post aged asphalt demonstrated improved high temperature stability. [ABSTRACT FROM AUTHOR]

Carbon microspheres (CMSs) were obtained via a simple hydrothermal method using fructose and xylose as the carbon sources, PEO106PPO70PEO106(F127) and poly(vinylpyrrolidone) (PVP) as the assistant agent. Carbon source and assistant agent have important effects on the morphologies of the products. Highly dispersed CMSs synthesized with fructose and F127 had an average size of 694 nm and smooth surfaces, and xylose-based CMSs had an average size of 620 nm. However, the carbon layer regularity of fructose-based CMSs is higher. In addition, there were almost no spheres with smooth surface in the products when adding PVP.Carbon microspheres (CMSs) were obtained via a simple hydrothermal method using fructose and xylose as the carbon source. PEO106PPO70PEO106(F127) was used as the assistant agent to improve the dispersibility of as-prepared CMSs. The morphologies of xylose-based CMSs with 620 nm were better than that of fructose-based CMSs with 694 nm.

A composite composed of waste package poly(vinyl chloride) (WPVC) and organic montmorillonite (OMMT) was prepared by coextrusion, which is used for modifying asphalt. The micromorphology of the WPVC/OMMT composite and its effect on the macroscopic properties of asphalt were studied using a fluorescent microscope and an X-ray diffractometer (XRD). The introduction of OMMT allows the WPVC to be good dispersed in the asphalt matrix, as demonstrated by differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR) analysis. The results indicate that asphalt modified by WPVC/OMMT composites with low OMMT content results in better high-temperature storage stability and physical properties of modified asphalt. [ABSTRACT FROM AUTHOR]

In view of environmental and economic aspect, asphalt was modified with recycled packaging waste expended polystyrene (WEPS) instead of common polymer. The differential scanning calorimetry (DSC), rotational viscometer and dynamic shear rheology (DSR) were used to analyze and evaluate the viscoelasticity of modified asphalt. Results indicate that the sensitivity of modified asphalt to temperature is decreased while the rut resistance of asphalt is increased. In addition, the viscoelasticity of asphalt is improved after the modification with WEPS. Besides, the modified asphalt has high viscosity at low temperature and low viscosity at high temperature, which is favorable for construction. [ABSTRACT FROM AUTHOR]

Nanotechnology has been gradually penetrated into the field of asphalt modification. Seemingly magic effects of nanomaterials have now been brought to improve the performance of asphalt. To demonstrate many of the prospective applications, researchers have conducted a series of positive and effective efforts dealing with the preparation of modified asphalt to demonstrate the mechanism of modification and the resultant improvement in performance. In this review, various nanomaterials used in asphalt modification are initially presented, followed by the methods employed to modify the asphalt with these materials and finally the effects of nanomaterials on the performance of base asphalt are presented and the modification mechanisms are discussed. Based on the current research results, the influence of preparation process parameters on the compatibility of every phase in the modified asphalt and the stability of the modified asphalt system are described. Finally, the development trend of the topic field is projected. [Copyright &y& Elsevier]

Waste polyethylene packaging (WPE) was used to modify asphalt, and hot storage stability of the modified asphalt was studied in this paper. The morphological change and component loss of WPE modified asphalt were characterized by fluorescence microscopy, Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), thermogravimetry (TG) and isolation testing. In addition, the mechanism of the hot storage stability of WPE modified asphalt was discussed. The results showed that the modification of asphalt with WPE was a physical process. It was found that the filament or partly network-like structure formed in the modified asphalt system was beneficial to improving the hot storage stability. Moreover, the addition of WPE resulted in a decrease in both the light components volatilization and the macromolecules decomposition of asphalt. It was demonstrated that when the content of WPE in matrix asphalt was less than 10 wt%, the service performances of modified asphalt could be better. [Copyright &y& Elsevier]

Uncontrollable morphology, high phase transition temperature and vague phase transition mechanism of vanadium dioxide (VO2) hinder its large-scale application in smart windows and optoelectronic switches. In this paper, controllable VO2(B) powders co-doped with W–Eu were synthesized via a hydrothermal method using CH3COOH·2H2O and H2O2as the reductant and assistant reductant, where W and Eu were derived from H2WO4and Eu(NO3)3·6H2O, respectively. Most VO2(B) crystals transformed into VO2(M) after annealing. Pristine VO2had a regular rectangular shape, and it would change to be fabric-like, spongy and coralloid after doping with W and Eu. Furthermore, the surface of W–Eu co-doped samples presented an urchin-like structure and nanorods appeared after annealing. Importantly, doping and annealing also have significant effects on the performances of VO2samples. Upon W–Eu co-doping, the phase transition temperature of VO2(M) samples decreased by an average of approximately 15 °C, and the energy band gap decreased from 0.70 eV to 0.33 eV corresponding to the change of phase transition temperature. Not only the thermochromic performances of VO2were optimized, but also the mechanisms were explained accordingly in this paper.

Barrier packaging materials are significant in protecting the packaged contents from damage caused by oxygen, fogging, fats and oils in the environment. In this study, an active barrier packaging composite based on lysozyme and plastic films including polyethylene (PE) and biaxially oriented polypropylene (BOPP) were designed. The barrier packaging composites were prepared using a layer-by-layer self-assembly process to deposit lysozyme onto the surface of the plastic films. The bulk structure and morphology of the composites were investigated using X-ray photoelectron spectroscopy and atomic force microscopy. The barrier properties of the packaging composites were analyzed by measuring water vapor permeability, oil permeability, oxygen permeability, light transmittance and chromaticity. The results showed that the lysozyme coating greatly reduced the water vapor permeability, oxygen permeability and oil permeability of the packaging without affecting the appearance of the original packaging films. The barrier properties of the packaging composites were strengthened by increasing the number of coated lysozyme layers. The composite films showed effective antibacterial activity against E. coliand S. aureusduring a pasteurized milk storage experiment, indicating a promising application prospect.

Three-dimensional (3D) compressible and elastic carbon materials, by virtue of lightweight, high electrical conductivity, excellent mechanical properties and thermal stability, high adsorption capacity and distinguished environmental compatibility, are attracting expanding attention and showing great promising applications in scientific and engineering fields, especially in flexible and wearable electronics. Herein, this review summaries the latest progress of 3D carbon compressible assemblies on the synthesis, properties and applications of carbon nanotubes and nanofiber sponges, graphene aerogels, biomass and synthetic polymer sponges. This paper also describes the relationship between the structural characteristics and properties, in terms of the introduction of heteroatoms, polymers, transition metal oxides/sulfides or other guests to improve the electrochemical properties of 3D carbon sponges. Furthermore, their applications in sensing, energy storage and conversion, environmental protection, thermal insulation and catalysis are discussed. Despite a number of diverse applications, a brief prospective on the challenges and outlooks are proposed.