Melamine sponge is a major concern for oil-water separation due to its lightweight,high porosity(>99%),cost-effectiveness,impressive mechanical properties,and chemical/thermal stability.However,its amphiphilic natu...Melamine sponge is a major concern for oil-water separation due to its lightweight,high porosity(>99%),cost-effectiveness,impressive mechanical properties,and chemical/thermal stability.However,its amphiphilic nature hinders selective oil absorption in water.Recent strategies to enhance hydrophobicity are reviewed,including synthetic methods and materials,with comprehensive explanations of the mechanisms driven by surface energy and roughness.Key performance indicators for MS in oil-water separation,including adsorption capacity,wettability,stability,emulsion separation,reversible wettability switching,flame retardancy,mechanical properties,and recyclability,are thoroughly discussed.In conclusion,this review provides insights into the future potential and direction of functional melamine sponges in oil-water separation.展开更多
With the rapid development of 5G communication technology and wearable electronic devices,the demand for low-reflection electromagnetic interference(EMI)shielding materials is becoming increasingly urgent.In this work...With the rapid development of 5G communication technology and wearable electronic devices,the demand for low-reflection electromagnetic interference(EMI)shielding materials is becoming increasingly urgent.In this work,reduced graphene oxide-MXene(rGMH)@FeNi/epoxy EMI shielding composites with a regular honeycomb structure were successfully prepared by the combination of surface functionalization modification,sacrificial template,and freeze-drying.The effects of magnetic FeNi alloy particle loading mode and loading amount on the EMI shielding performance of composites were investigated.The results show that rGMH@FeNi/epoxy EMI shielding composites have the highest EMI shielding effectiveness(EMI SE)and the lowest reflection shielding effectiveness when magnetic FeNi alloy particles are loaded only on the graphene skeleton.In this composite,the EMI SE value of the composite is 61 dB when the rGMH@FeNi mass fraction is 5.4 wt%(f-FeNi mass fraction is 0.9 wt%),which is 4.7 times that of the blended rGO/MXene/FeNi/epoxy resin composite(13 dB)with the same mass fraction.At the same time,the rGMH@FeNi/epoxy composite has excellent thermal stability(heat-resistance index of 190.3℃)and mechanical properties(energy storage modulus of 8606.7 MPa).These polymer-based EMI shielding composites with excellent EMI shielding properties and low reflection effectiveness have great potential in the protection of high-power,portable and wearable electronic devices against electromagnetic pollution.展开更多
The conductive polymer poly(3,4-thylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)exhibits po-tential in the development of flexible devices due to its unique conjugated structure and water-solubility characteri...The conductive polymer poly(3,4-thylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)exhibits po-tential in the development of flexible devices due to its unique conjugated structure and water-solubility characteristics.To address the incompressibility of the original PEDOT:PSS aerogel without compromis-ing its high conductivity,a stable interpenetrating polymer network(IPN)was self-assembled by guiding the molecular motion within PEDOT:PSS and introducing multi-walled carbon nanotubes(MWCNTs).By combining critical surface removal,directional freeze-drying,and polydimethylsiloxane(PDMS)reinforce-ment processes,a hydrophobic PDMS@MWCNTs/PP aerogel with a highly oriented porous structure and high strength was prepared.Under the synergistic effect of MWCNTs/PEDOT:PSS electroactive scaffold,the composite aerogel exhibited a high sensitivity of up to 16.603 kPa^(-1) at 0-2 kPa,a fast response time of 74 ms,and excellent repeatability.Moreover,the sensor possessed hydrophobicity with a good water contact angle of 137°The sensor could serve as a wearable electronic monitoring device to achieve ac-curate and sensitive detection of human motion including large-scale human activities and tiny muscle movements.Therefore,our findings provide a new direction to fabricate high-performance piezoresistive sensors based on three-dimensional(3D)conductive polymer active scaffolds,demonstrating their great potential for flexible electronics,human-computer interaction,and a wide range of applications under special working conditions.展开更多
Environmental contamination has been caused by petroleum-based polymeric materials in the melt deposition process.Nowadays biodegradable materials have been widely used in the fused deposition modeling(FDM)industry,su...Environmental contamination has been caused by petroleum-based polymeric materials in the melt deposition process.Nowadays biodegradable materials have been widely used in the fused deposition modeling(FDM)industry,such as polylactic acid(PLA).However,internal complex thermal stress and deformations in part caused by an uneven distribution of PLA filament deposition temperatures during FDM,which will seriously affect the geometric accuracy of the printed part.In order to reduce material waste and environmental pollution during the printing process,the accuracy of PLA part can be improved.Herein,numerical simulation was carried out to investigate the temperature field and stress field during the building and cooling process of cuboid specimens.The effects of printing path on the thermal stress and temperature field during the building process were mainly studied.The results show that the printing path has a significant effect on the stress distribution.The most uni-form stress distribution and the smallest deformation were obtained using the Zig Zag printing path.Finally,the residual stress during the cooling process was collected using strain gauges embedded at the mid-plane of the FDM built cuboid specimens.The simulation results are consistent with the experimental results.展开更多
Printing quality evaluation is an important means to check whether prints are qualfied.However,the urrent printing quality evaluation system for gravure decorative paper is not perfect.In order to solve this problem,a...Printing quality evaluation is an important means to check whether prints are qualfied.However,the urrent printing quality evaluation system for gravure decorative paper is not perfect.In order to solve this problem,a method for evaluating quality of decorative paper based on analytical hierarchy process(AHP)and the entropy weight method(EWM)model is proposed in this paper.So as to verify the proposed model,decorative paper of different grades was selected as the experimental objects.Firstly,the data about five indices eflecting printing quality were measured.Secondly,the evaluation model was used to assign weights to the indices,and scores in each index were calculated according to scoring tables.Finally,the evalua tion scores were statistically analyzed.The results of data analysis showed that the 95% confidence intervals and coefficients of variation were small.The average error of the evaluation system was 0.2061.It indicates that the model can stably distinguish decorative paper of diferent grades,accuracy of which is high.The research in this paper can provide reference to the quality improvement of decorative paper and the printing quality evaluation of other paper.展开更多
Wearable sensors are pivotal for point-of-care diagnostics,yet their application in extreme conditions is rarely conducted.In this work,we present a wearable pH sensor using tungsten oxide aerogel(TOA)as the sensing m...Wearable sensors are pivotal for point-of-care diagnostics,yet their application in extreme conditions is rarely conducted.In this work,we present a wearable pH sensor using tungsten oxide aerogel(TOA)as the sensing material.With the advantages of large specific surface area,high porosity and interconnected network structures,TOA not only provides excellent pH sensing performance but also demonstrates remarkable structural and sensing stability.The potentiometric pH sensor exhibits a high sensitivity(−63.70 mV/pH),a low detectable limit(0.05)and a superior stability(maintained over 50,000 s).Integrated with a Bluetooth module,the wearable sensor achieves non-invasive and real-time pH monitoring on the human skin with minimal deviation(1.91%)compared to the commercial pH meter.More importantly,the anti-impact behaviors of the TOA-based sensing materials and chip,along with the pH wearable sensor on a pig exhibit an outstanding shock-resistance ability,with variations no more than 7.17%under an impact of 118.38 kPa.Therefore,this study shows great promise for the aerogel-based personalized health management in the extreme environment.展开更多
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 ...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, anticounterfeiting 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.展开更多
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 hydrothe...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℃ 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.展开更多
Multi-faults detection is a challenge for rolling bearings due to the mode mixture and coupling of multiple fault features,as well as its easy burying in the complex,non-stationary structural vibrations and strong bac...Multi-faults detection is a challenge for rolling bearings due to the mode mixture and coupling of multiple fault features,as well as its easy burying in the complex,non-stationary structural vibrations and strong background noises.In this paper,a method based on the flexible analytical wavelet transform(FAWT)possessing fractional scaling and translation factors is proposed to identify multiple faults occurred in different components of rolling bearings.During the route of the proposed method,the proper FAWT bases are constructed via genetic optimization algorithm(GA)based on maximizing the spectral correlated kurtosis(SCK)which is firstly presented and proved to be efficient and effective in indicating interested fault mode.Via using the customized FAWT bases for each interested fault mode,the original vibration measurements are decomposed into fine frequency subbands,and the sensitive subband which enhances the signal-to-noise ratio(SNR)is selected to exhibit the fault signature on its envelope spectrum.The proposed method is tested via simulated signals,and applied to analyze the experimental vibration measurements from the running roller bearings subjected to outrace,inner-race and roller defects.The analysis results validate the effectiveness of the proposed method in identifying multi-faults occurred in different components of rolling bearings.展开更多
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 successfull...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 k J/m^(2) 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.展开更多
waterborne polyurethane (WPU) dispersions have gained attention towards environm entally-friendly synthesis. In this article, a series of waterborne polyurethane em ulsions was successfully synthesized and extensively...waterborne polyurethane (WPU) dispersions have gained attention towards environm entally-friendly synthesis. In this article, a series of waterborne polyurethane em ulsions was successfully synthesized and extensively characterized in terms of thermal, mechanical properties, hydrophilic behavior and morphology. Snowwas chosen as dispersant instead of comm only used water. Preparation param eters 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 com paring the nature of the polyols (PPG, PEG and PNA, 2000g/mol) of this study, as-synthesized polyether waterborne polyurethane provided higher solid content, viscosity and water-resistance. However, polyester waterborne polyurethane perform ed differently and it exhibited higher therm al stability and crystallinity. When com paring 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 2000g/mol PPG provided the highest solid content and lowest viscosity. It was observed th at particle size was uniform and highly dispersed for all sam ples from TEM images. Therm ogravim etric, differential scanning calorim etry (DSC) and X-ray diffraction results dem onstrated that the emulsion WPU-N230 with m olecular weight of 3000 g/mol PPG possessed higher therm al stability and crystallinity than the other samples. The reason was that the Tg and thermal stability were increased with increasing molecular weight. when molecular weight increased, the arrangem ent of soft segm ent 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.展开更多
Anionomer-type waterborne polyurethane dispersions （PUDs） were obtained from poly （propylene glycol） （PPG）, isophorone diisocyanate （IPDI） and dimethylolpropionic acid （DMPA） through a modified prepolymer is...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 polyure- thanes. 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, oartial acid values and electrolvtic stability.展开更多
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 se...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.展开更多
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-synthesize...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 1–1.4μm and a specific surface area of 452 m^2/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.展开更多
Cellulose plays a key role in abundant organic natural materials meeting the increasing demand for green and biocompatible products.The highly crystalline nanoscale component of cellulose nanocrystals has recently att...Cellulose plays a key role in abundant organic natural materials meeting the increasing demand for green and biocompatible products.The highly crystalline nanoscale component of cellulose nanocrystals has recently attracted great attention due to the versatile performance as filler or matrix in producing functional materials.In this work,we prepared the waterborne polyurethane via a prepolymer process,and obtained cellulose and cellulose nanocrystals from waste paper via a facile acid hydrolysis process.After that,the cellulose nanocrystals were assembled into film and mixed with polyurethane to prepare flexible polyurethane/cellulose nanocrystals composite membrane with different soaking time.The correlation between the bulk structure and applied properties including thermal resistance and mechanical property was investigated by using Fourier transform infrared spectroscopy(FTIR),X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),scanning electron microscopy(SEM),thermogravimetric analysis(TGA),differential scanning calorimetry(DSC)and folding test.The structure analysis indicates that cellulose nanocrystals prepared from used paper have a quality similar to that of commercial cellulose.Meanwhile,the cellulose nanocrystals have been mixed with polyurethane uniformly.Polyurethane can significantly benefit to the thermal resistance and mechanical property of the cellulose nanocrystals film.The polyurethane/cellulose nanocrystals composite membrane present good flexibility and may hold a significantly potential application as visual and flexible material.展开更多
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 ind...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,αHelix,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.展开更多
High precision control of substrate tension is the premise and guarantee for producing high-quality products in roll-to-roll precision coating machine.However,the complex relationships in tension system make the probl...High precision control of substrate tension is the premise and guarantee for producing high-quality products in roll-to-roll precision coating machine.However,the complex relationships in tension system make the problems of decoupling control difficult to be solved,which has limited the improvement of tension control accuracy for the coating machine.Therefore,an ADRC parameters self-tuning decoupling strategy based on RBF neural network is proposed to improve the control accuracy of tension system in this paper.Firstly,a global coupling nonlinear model of the tension system is established according to the composition of the coating machine,and the global coupling model is linearized based on the first-order Taylor formula.Secondly,according to the linear model of the tension system,a parameters self-tuning decoupling algorithm of the tension system is proposed by integrating feedforward control,ADRC and RBF.Finally,the simulation results show that the proposed tension control strategy has good decoupling control performance and effectively improves the tension control accuracy for the coating machine.展开更多
Flexible, lightweight, robust and versatile properties are essential for the next generation of wearable as well as intelligent electromagnetic interference(EMI) shielding materials. In this work, multilayered films c...Flexible, lightweight, robust and versatile properties are essential for the next generation of wearable as well as intelligent electromagnetic interference(EMI) shielding materials. In this work, multilayered films containing cellulose nanofiber(CNF) layers, CNF/MXene layers, and CNF/silver nanowires(CNF/Ag NWs)layers were fabricated by an efficient and easy-to-use vacuum filtration method. Compared with a uniformly mixed film, the resultant layered composite films that loaded with a low MXene and AgNWs content exhibit superior mechanical properties with a tensile strength of 137 MPa, a strain at break of 5.7%, excellent EMI shielding effectiveness(EMI SE) of 61.9 d B, and higher EMI SE/t of 20,653 d B cm^(-1).This is attributed to the high-performance CNF substrate, the highly efficient layered structures, and extensive hydrogen-bonding interactions. In particular, a high degree of ohmic loss of multiple interfaces and polarization relaxation of local defects, as well as an abundance of terminal groups, favor the loss of electromagnetic waves(EMW) within the material. In addition, the prepared multifunctional layered composite films also show good antibacterial properties. As a result, the obtained new kind of flexible layered structure EMI shielding composite films with excellent EMI shielding performance, and mechanical properties present promising application prospects in the fields of EMI shielding and protection for aerospace, portable, and wearable flexible electronic devices.展开更多
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 pro...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%.展开更多
Non-precious electro catalysts with high-efficiency, cheapness and stablility are of great significance to replace noble metal electro catalysts in the hydrogen evolution reaction(HER) and oxygen evolution reaction(OE...Non-precious electro catalysts with high-efficiency, cheapness and stablility are of great significance to replace noble metal electro catalysts in the hydrogen evolution reaction(HER) and oxygen evolution reaction(OER). In this work, triangular Cu@CuO nanorods on Cu nanosheets were fabricated by a novel in-situ oxidation approach using Cu nanosheets as self-template and conductive nano-substrate in an aqueous solution of NaOH/H2O2, and then by lowtemperature phosphorization treatments. The experimental results show that the phosphating temperature has a significant effect on the morphology, composition and number of active sites of Cu@Cu_(3)P nanorods. The Cu@Cu_(3)P-280 electrode exhibits a good HER catalytic activity of achieving a current density of 10 mA/cm^(2) at 252 mV in acid electrolyte. After catalysis for 14 h, the current density can still reach 72% of the initial value. Moreover, the Cu@Cu_(3)P-280 electrode also shows an excellent OER catalytic activity in basic electrolyte, reaching a current density of 10 mA/cm^(2) at the overpotential value of 200 mV. After catalysis for 12 h, the current density remained more than 93% of the initial value. This work provides a theoretical basis for the directional design and preparation of sustainable, low-cost, bifunctional electrocatalytic materials.展开更多
基金supported by the National Natural Science Foundation of China(Nos.52372093 and 52102145)the Key R&D Program of Shaanxi Province(Nos.2023GXLH-045 and 2022SF-168)+4 种基金the Xi’an Programs for Science and Technology Plan(Nos.2020KJRC0090 and 21XJZZ0045)the Opening Project of Shanxi Key Laboratory of Advanced Manufacturing Technology(No.XJZZ202001)the Xi’an Municipal Bureau of Science and Technology(No.21XJZZ0054)the Open Foundation of Key Laboratory of Auxiliary Chemistry and Technology for Chemical Industry,Ministry of Education,Shaanxi University of Science and Technology(No.KFKT2021-01)the Shaanxi Collaborative Innovation Center of Industrial Auxiliary Chemistry and Technology,Shaanxi University of Science and Technology(No.KFKT2021-01).
文摘Melamine sponge is a major concern for oil-water separation due to its lightweight,high porosity(>99%),cost-effectiveness,impressive mechanical properties,and chemical/thermal stability.However,its amphiphilic nature hinders selective oil absorption in water.Recent strategies to enhance hydrophobicity are reviewed,including synthetic methods and materials,with comprehensive explanations of the mechanisms driven by surface energy and roughness.Key performance indicators for MS in oil-water separation,including adsorption capacity,wettability,stability,emulsion separation,reversible wettability switching,flame retardancy,mechanical properties,and recyclability,are thoroughly discussed.In conclusion,this review provides insights into the future potential and direction of functional melamine sponges in oil-water separation.
基金support and funding from the National Natural Science Foundation of China(Nos.52303104,52203100 and 52403132)Young Talent Fund of Association for Science and Technology in Shaanxi,China(No.20240455)+4 种基金Basic Research Program of Natural Science of Shaanxi Province(No.2024JCYBMS-275)Natural Science Foundation of Chongqing,China(No.2023NSCQ-MSX2682)the Doctoral Research Start-up Funds of Xi’an University of Technology(No.108/451122007)Innovation Foundation for Doctor Dissertation of Northwestern Polytechnical University(No.CX2024094)the Transformation Projects of Scientific and Technological Achievements of Qinchuangyuan Platform(2023JH-QCYCK-0026).
文摘With the rapid development of 5G communication technology and wearable electronic devices,the demand for low-reflection electromagnetic interference(EMI)shielding materials is becoming increasingly urgent.In this work,reduced graphene oxide-MXene(rGMH)@FeNi/epoxy EMI shielding composites with a regular honeycomb structure were successfully prepared by the combination of surface functionalization modification,sacrificial template,and freeze-drying.The effects of magnetic FeNi alloy particle loading mode and loading amount on the EMI shielding performance of composites were investigated.The results show that rGMH@FeNi/epoxy EMI shielding composites have the highest EMI shielding effectiveness(EMI SE)and the lowest reflection shielding effectiveness when magnetic FeNi alloy particles are loaded only on the graphene skeleton.In this composite,the EMI SE value of the composite is 61 dB when the rGMH@FeNi mass fraction is 5.4 wt%(f-FeNi mass fraction is 0.9 wt%),which is 4.7 times that of the blended rGO/MXene/FeNi/epoxy resin composite(13 dB)with the same mass fraction.At the same time,the rGMH@FeNi/epoxy composite has excellent thermal stability(heat-resistance index of 190.3℃)and mechanical properties(energy storage modulus of 8606.7 MPa).These polymer-based EMI shielding composites with excellent EMI shielding properties and low reflection effectiveness have great potential in the protection of high-power,portable and wearable electronic devices against electromagnetic pollution.
基金supported by the Xi’an Science and Technology Plan Project(Nos.GXYD14.27 and GX2338)the Key Scientific Research Program of Shaanxi Provincial Depart-ment of Education(Nos.22JY046 and 21JY032)+1 种基金the Opening Project of Shanxi Key Laboratory of Advanced Manufacturing Tech-nology of North University of China(No.XJZZ202104)the General Project of Natural Science Basic Research Program of Shaanxi Provincial Department of Science and Technology(No.2023-JC-YB-424)。
文摘The conductive polymer poly(3,4-thylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)exhibits po-tential in the development of flexible devices due to its unique conjugated structure and water-solubility characteristics.To address the incompressibility of the original PEDOT:PSS aerogel without compromis-ing its high conductivity,a stable interpenetrating polymer network(IPN)was self-assembled by guiding the molecular motion within PEDOT:PSS and introducing multi-walled carbon nanotubes(MWCNTs).By combining critical surface removal,directional freeze-drying,and polydimethylsiloxane(PDMS)reinforce-ment processes,a hydrophobic PDMS@MWCNTs/PP aerogel with a highly oriented porous structure and high strength was prepared.Under the synergistic effect of MWCNTs/PEDOT:PSS electroactive scaffold,the composite aerogel exhibited a high sensitivity of up to 16.603 kPa^(-1) at 0-2 kPa,a fast response time of 74 ms,and excellent repeatability.Moreover,the sensor possessed hydrophobicity with a good water contact angle of 137°The sensor could serve as a wearable electronic monitoring device to achieve ac-curate and sensitive detection of human motion including large-scale human activities and tiny muscle movements.Therefore,our findings provide a new direction to fabricate high-performance piezoresistive sensors based on three-dimensional(3D)conductive polymer active scaffolds,demonstrating their great potential for flexible electronics,human-computer interaction,and a wide range of applications under special working conditions.
基金funded by Shanxi Province Technology Innovation Guidance Special Project(2020QFY03-05)Shanxi Province Printing and Packaging Key Laboratory Project(16JS081).
文摘Environmental contamination has been caused by petroleum-based polymeric materials in the melt deposition process.Nowadays biodegradable materials have been widely used in the fused deposition modeling(FDM)industry,such as polylactic acid(PLA).However,internal complex thermal stress and deformations in part caused by an uneven distribution of PLA filament deposition temperatures during FDM,which will seriously affect the geometric accuracy of the printed part.In order to reduce material waste and environmental pollution during the printing process,the accuracy of PLA part can be improved.Herein,numerical simulation was carried out to investigate the temperature field and stress field during the building and cooling process of cuboid specimens.The effects of printing path on the thermal stress and temperature field during the building process were mainly studied.The results show that the printing path has a significant effect on the stress distribution.The most uni-form stress distribution and the smallest deformation were obtained using the Zig Zag printing path.Finally,the residual stress during the cooling process was collected using strain gauges embedded at the mid-plane of the FDM built cuboid specimens.The simulation results are consistent with the experimental results.
基金This work was supported in part by the National Natural Science Foundation of China under Grant 62076199the Opening Foundation of State Key Laboratory of Power System of Tractor under Grant SKT2022004+2 种基金Humanities and Social Sciences Research Planning Project of the Ministry of Education under Grant 17YJC760007in part by Doctoral Scientific Research Foundation of Xi’an University of Technology under Grant 108-451121001Shaanxi Collaborative Innovation Center of Green Intelligent Printing and Packaging.
文摘Printing quality evaluation is an important means to check whether prints are qualfied.However,the urrent printing quality evaluation system for gravure decorative paper is not perfect.In order to solve this problem,a method for evaluating quality of decorative paper based on analytical hierarchy process(AHP)and the entropy weight method(EWM)model is proposed in this paper.So as to verify the proposed model,decorative paper of different grades was selected as the experimental objects.Firstly,the data about five indices eflecting printing quality were measured.Secondly,the evaluation model was used to assign weights to the indices,and scores in each index were calculated according to scoring tables.Finally,the evalua tion scores were statistically analyzed.The results of data analysis showed that the 95% confidence intervals and coefficients of variation were small.The average error of the evaluation system was 0.2061.It indicates that the model can stably distinguish decorative paper of diferent grades,accuracy of which is high.The research in this paper can provide reference to the quality improvement of decorative paper and the printing quality evaluation of other paper.
基金supported by the National Natural Science Foundation of China(Nos.22374119 and 22274127)the Research Fund of the State Key Laboratory of Solidification Processing(NPU),China(No.2021-QZ-01)+1 种基金the Key Project of Natural Science Fund of Shaanxi Province(Nos.2023-JC-ZD-06 and 2024JC-YBQN-0636)the Open Project of the State Key Laboratory of Transducer Technology(No.SKT2307).
文摘Wearable sensors are pivotal for point-of-care diagnostics,yet their application in extreme conditions is rarely conducted.In this work,we present a wearable pH sensor using tungsten oxide aerogel(TOA)as the sensing material.With the advantages of large specific surface area,high porosity and interconnected network structures,TOA not only provides excellent pH sensing performance but also demonstrates remarkable structural and sensing stability.The potentiometric pH sensor exhibits a high sensitivity(−63.70 mV/pH),a low detectable limit(0.05)and a superior stability(maintained over 50,000 s).Integrated with a Bluetooth module,the wearable sensor achieves non-invasive and real-time pH monitoring on the human skin with minimal deviation(1.91%)compared to the commercial pH meter.More importantly,the anti-impact behaviors of the TOA-based sensing materials and chip,along with the pH wearable sensor on a pig exhibit an outstanding shock-resistance ability,with variations no more than 7.17%under an impact of 118.38 kPa.Therefore,this study shows great promise for the aerogel-based personalized health management in the extreme environment.
基金the National Natural Science Foundation of China(Grant Nos.51372200 and 51772243)the Foundation of the State Key Laboratory of Solidification Processing in NWPU(Grant No.SKLSP201753)+2 种基金Scientific Research Plan Projects of Shaanxi Education Department(Grant No.16JK1551)Technology Innovation Programme of Xi’an University of Technology(Grant No.2016CX030)China Postdoctoral Science Foundation(Grant No.2016M592824)
文摘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, anticounterfeiting 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.
基金supported by the fund of the Beijing Laboratory for Food Quality and Safety, Beijing Technology and Business University (Grant No. FQS-201709)China Postdoctoral Science Foundation Funded Project (Grant No. 2016M592824)+1 种基金the Science and Technology Plan of Yulin City (Grant No. 2016-16-7)the Science and Technology Plan of Beilin District (Grant No. GX1710)
文摘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℃ 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.
基金co-supported by the Fundamental Research Funds for the Central Universities of China,China Postdoctoral Science Foundation(No.2018M631196)the National Natural Foundation of China(No.51705420).
文摘Multi-faults detection is a challenge for rolling bearings due to the mode mixture and coupling of multiple fault features,as well as its easy burying in the complex,non-stationary structural vibrations and strong background noises.In this paper,a method based on the flexible analytical wavelet transform(FAWT)possessing fractional scaling and translation factors is proposed to identify multiple faults occurred in different components of rolling bearings.During the route of the proposed method,the proper FAWT bases are constructed via genetic optimization algorithm(GA)based on maximizing the spectral correlated kurtosis(SCK)which is firstly presented and proved to be efficient and effective in indicating interested fault mode.Via using the customized FAWT bases for each interested fault mode,the original vibration measurements are decomposed into fine frequency subbands,and the sensitive subband which enhances the signal-to-noise ratio(SNR)is selected to exhibit the fault signature on its envelope spectrum.The proposed method is tested via simulated signals,and applied to analyze the experimental vibration measurements from the running roller bearings subjected to outrace,inner-race and roller defects.The analysis results validate the effectiveness of the proposed method in identifying multi-faults occurred in different components of rolling bearings.
基金funded by China Postdoctoral Science Foundation(No.2018M643699)the Xi’an Science and Technology Bureau Innovation Leading Projects(No.201805037YD15CG21(23))+2 种基金the Natural Science Foundation of Shaanxi Province(No.2019JQ741)the Science and Technology Bureau of Beilin District,Xi’an(No.GX2035)the Postdoctoral Science Foundation of Shaanxi Province(No.2018BSHEDZZ101)。
文摘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 k J/m^(2) 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.
基金supported by the National Natural Science Foundation of China (Grant No. 51772243)PhD Research Startup Foundation of Xi’an University of Technology (Grant No. 108256081703)+4 种基金Beijing Laboratory for Food Quality and Safety, Beijing Technology and Business University (Grant No. FQS-201709)the Innovative Team Support Program (2017KCT-17)Key Laboratory of Processing and Quality Evaluation Technology of Green Plastics of China National Light Industry Council, Beijing Technology and Business University (Grant No. BS201702)the China Postdoctoral Science Foundation Funded Project (Grant No. 2016M592824)the Science and Technology Plan of Yulin City (Grant No. 2016-16-7), and the Science and Technology Plan of Beilin District (Grant No. GX1710)
文摘waterborne polyurethane (WPU) dispersions have gained attention towards environm entally-friendly synthesis. In this article, a series of waterborne polyurethane em ulsions was successfully synthesized and extensively characterized in terms of thermal, mechanical properties, hydrophilic behavior and morphology. Snowwas chosen as dispersant instead of comm only used water. Preparation param eters 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 com paring the nature of the polyols (PPG, PEG and PNA, 2000g/mol) of this study, as-synthesized polyether waterborne polyurethane provided higher solid content, viscosity and water-resistance. However, polyester waterborne polyurethane perform ed differently and it exhibited higher therm al stability and crystallinity. When com paring 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 2000g/mol PPG provided the highest solid content and lowest viscosity. It was observed th at particle size was uniform and highly dispersed for all sam ples from TEM images. Therm ogravim etric, differential scanning calorim etry (DSC) and X-ray diffraction results dem onstrated that the emulsion WPU-N230 with m olecular weight of 3000 g/mol PPG possessed higher therm al stability and crystallinity than the other samples. The reason was that the Tg and thermal stability were increased with increasing molecular weight. when molecular weight increased, the arrangem ent of soft segm ent 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.
基金?nancial support provided by Program for New Century Excellent Talents in University by the Ministry of Education of China(Grant No.NCET-12-1045)the Shaanxi Programs for Science and Technology Development(No.2010K01-096)Ph.D.Innovation Fund Projects of Xi’an University of Technology(No.310-252071501)
文摘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 polyure- thanes. 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, oartial acid values and electrolvtic stability.
基金financially supported by the National Natural Science Foundation of China(Nos.51802259 and 51772243)the China Postdoctoral Science Foundation Funded Project(No.2019M663785)+3 种基金the Natural Science Foundation of Shaanxi(No.2019JQ-510)Xi’an and Xi’an Beilin District Programs for Science and Technology Plan(Nos.201805037YD15CG21(18)and GX1913)the Promotion Program for Youth of Shaanxi University Science and Technology Association(No.20190415)the Fund of Key laboratory of Processing and Quality Evaluation Technology of Green Plastics of China National Light Industry Council(No.PQETGP2019003)。
文摘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.
基金supported financially by the Outstanding Youth Science Fund of Shaanxi Province(No.2018JC-028)the fund of Beijing Key Laboratory of Quality Evaluation Technology for Hygiene and Safety of Plastics,Beijing Technology and Business University(No.51772243)+1 种基金the Innovation Team Plan of Shaanxi Province(No.2017KCT-17)the National Natural Science Foundation of China(No.51772243).
文摘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 1–1.4μm and a specific surface area of 452 m^2/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.
基金support provided by the National Natural Science Foundation of China[Grant No.51802259]China Postdoctoral Science Foundation Funded Project[Grant No.2019M663785]+4 种基金the Natural Science Foundation of Shaanxi[Grant No.2019JQ-510]the Natural Science Basic Research Plan in Shaanxi Province of China[Grant No.2018JM5053],Xi’an and Xi’an Beilin District Programs for Science and Technology Plan[Grant No.201805037YD15CG21(18)and GX1913]the Promotion Program for Youth of Shaanxi University science and technology association[Grant No.20190415]Fund of Key laboratory of Processing and Quality Evaluation Technology of Green Plastics of China National Light Industry council[Grant No.PQETGP2019003]the Ph.D.Start-up fund project[Grant No.108-451118001]of Xi’an University of Technology.
文摘Cellulose plays a key role in abundant organic natural materials meeting the increasing demand for green and biocompatible products.The highly crystalline nanoscale component of cellulose nanocrystals has recently attracted great attention due to the versatile performance as filler or matrix in producing functional materials.In this work,we prepared the waterborne polyurethane via a prepolymer process,and obtained cellulose and cellulose nanocrystals from waste paper via a facile acid hydrolysis process.After that,the cellulose nanocrystals were assembled into film and mixed with polyurethane to prepare flexible polyurethane/cellulose nanocrystals composite membrane with different soaking time.The correlation between the bulk structure and applied properties including thermal resistance and mechanical property was investigated by using Fourier transform infrared spectroscopy(FTIR),X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),scanning electron microscopy(SEM),thermogravimetric analysis(TGA),differential scanning calorimetry(DSC)and folding test.The structure analysis indicates that cellulose nanocrystals prepared from used paper have a quality similar to that of commercial cellulose.Meanwhile,the cellulose nanocrystals have been mixed with polyurethane uniformly.Polyurethane can significantly benefit to the thermal resistance and mechanical property of the cellulose nanocrystals film.The polyurethane/cellulose nanocrystals composite membrane present good flexibility and may hold a significantly potential application as visual and flexible material.
基金the National Natural Science Foundation of China(Nos.51802259and 51772243)China Postdoctoral Science Foundation Funded Project(No.2019M663785)+4 种基金the Natural Science Foundation of Shaanxi(No.2019JQ-510)Xi’an and Xi’an Beilin District Programs for Science and Technology Plan(Nos.201805037YD15CG21(18)and GX1913)the Promotion Program for Youth of Shaanxi University Science and Technology Association(No.20190415)Fund of Key laboratory of Processing and Quality Evaluation Technology of Green Plastics of China National Light Industry Council(No.PQETGP2019003)the Ph.D.Start-up Fund Project(No.108-451118001)of Xi’an University of Technology。
文摘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,αHelix,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.
基金supported by the National Key Research and Development Program of China(Grant No.2019YFB1707200)the Key Research and Development Program of Shaanxi Province(Grant No.2020ZDLGY14-06)the Technology Innovation Leading Program of Shaanxi Province(Grant No.2020QFY03-03).
文摘High precision control of substrate tension is the premise and guarantee for producing high-quality products in roll-to-roll precision coating machine.However,the complex relationships in tension system make the problems of decoupling control difficult to be solved,which has limited the improvement of tension control accuracy for the coating machine.Therefore,an ADRC parameters self-tuning decoupling strategy based on RBF neural network is proposed to improve the control accuracy of tension system in this paper.Firstly,a global coupling nonlinear model of the tension system is established according to the composition of the coating machine,and the global coupling model is linearized based on the first-order Taylor formula.Secondly,according to the linear model of the tension system,a parameters self-tuning decoupling algorithm of the tension system is proposed by integrating feedforward control,ADRC and RBF.Finally,the simulation results show that the proposed tension control strategy has good decoupling control performance and effectively improves the tension control accuracy for the coating machine.
基金supported by the National Natural Science Foundation of China(Nos.51773167,52102303,52103095)the China Postdoctoral Science Foundation(No.2019M650268)+1 种基金the Opening Project of State Key Laboratory of Polymer Materials Engineering(Sichuan University)(No.sklpme2021-05-09)Foundation of Education Department of Shaanxi Province(No.20JK0805)。
文摘Flexible, lightweight, robust and versatile properties are essential for the next generation of wearable as well as intelligent electromagnetic interference(EMI) shielding materials. In this work, multilayered films containing cellulose nanofiber(CNF) layers, CNF/MXene layers, and CNF/silver nanowires(CNF/Ag NWs)layers were fabricated by an efficient and easy-to-use vacuum filtration method. Compared with a uniformly mixed film, the resultant layered composite films that loaded with a low MXene and AgNWs content exhibit superior mechanical properties with a tensile strength of 137 MPa, a strain at break of 5.7%, excellent EMI shielding effectiveness(EMI SE) of 61.9 d B, and higher EMI SE/t of 20,653 d B cm^(-1).This is attributed to the high-performance CNF substrate, the highly efficient layered structures, and extensive hydrogen-bonding interactions. In particular, a high degree of ohmic loss of multiple interfaces and polarization relaxation of local defects, as well as an abundance of terminal groups, favor the loss of electromagnetic waves(EMW) within the material. In addition, the prepared multifunctional layered composite films also show good antibacterial properties. As a result, the obtained new kind of flexible layered structure EMI shielding composite films with excellent EMI shielding performance, and mechanical properties present promising application prospects in the fields of EMI shielding and protection for aerospace, portable, and wearable flexible electronic devices.
基金financially support provided by the National Natural Science Foundation of China (Grant No. 51772243)the Innovation Team Plan of Shaanxi Province (Grant No. 2017KCT-17)+1 种基金the China Postdoctoral Science Foundation Funded Project (Grant No. 2016M592824)the fund of the State Key Laboratory of Solidfication Processing in NWPU SKLSP201625
文摘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%.
基金Project(21905232) supported by the National Natural Science Foundation of China。
文摘Non-precious electro catalysts with high-efficiency, cheapness and stablility are of great significance to replace noble metal electro catalysts in the hydrogen evolution reaction(HER) and oxygen evolution reaction(OER). In this work, triangular Cu@CuO nanorods on Cu nanosheets were fabricated by a novel in-situ oxidation approach using Cu nanosheets as self-template and conductive nano-substrate in an aqueous solution of NaOH/H2O2, and then by lowtemperature phosphorization treatments. The experimental results show that the phosphating temperature has a significant effect on the morphology, composition and number of active sites of Cu@Cu_(3)P nanorods. The Cu@Cu_(3)P-280 electrode exhibits a good HER catalytic activity of achieving a current density of 10 mA/cm^(2) at 252 mV in acid electrolyte. After catalysis for 14 h, the current density can still reach 72% of the initial value. Moreover, the Cu@Cu_(3)P-280 electrode also shows an excellent OER catalytic activity in basic electrolyte, reaching a current density of 10 mA/cm^(2) at the overpotential value of 200 mV. After catalysis for 12 h, the current density remained more than 93% of the initial value. This work provides a theoretical basis for the directional design and preparation of sustainable, low-cost, bifunctional electrocatalytic materials.
