Electroconductive hydroxy-sodalite/graphite composites were synthesized by alkali-activation of kaolinite in the presence of sodium hydroxide as the alkali activator and graphite as a conductive filler. Thermal, morph...Electroconductive hydroxy-sodalite/graphite composites were synthesized by alkali-activation of kaolinite in the presence of sodium hydroxide as the alkali activator and graphite as a conductive filler. Thermal, morphological and microstructural properties in addition to direct current (D.C.) conductivity of the prepared composites were investigated. Thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy in the attenuated total reflection mode (FTIR/ATR), X-ray diffraction (XRD), scanning electron microscope/energy dispersive using X-ray analysis (SEM/EDX) and DC conductivity measurements were used to characterize the prepared composites. The effect of the hydroxyl-sodalite-to-graphite and NaOH-to-kaolinite ratios on the electrical conductivity was investigated and evaluated on the generated composite specimens made of Jordanian kaolinite or pure kaolinite. It was demonstrated that increasing the mass ratio of graphite-to-kaolinite in the clay-based composites increased the electrical conductivity of the resultant composites. It was also observed that using 1:1 graphite-to-pure kaolinite mass ratio showed the best electrical conductivity value of 3 × 10-3 s/cm, among the other mass ratios used for pure kaolinite specimens, while using 1:1 mass ratio of graphite-to-Jordanian kaolinite showed a conductivity of 1.6 s/cm.展开更多
Waterborne pathogens pose a lifelong threat, necessitating advanced disinfection systemswith state-of-the-art materials. Laser-Induced Graphene (LIG), a 3-dimensional form ofgraphene, is a widely known electrode mater...Waterborne pathogens pose a lifelong threat, necessitating advanced disinfection systemswith state-of-the-art materials. Laser-Induced Graphene (LIG), a 3-dimensional form ofgraphene, is a widely known electrode material for its electrically-induced antimicrobialproperties. However, LIG surfaces exhibit antimicrobial properties exclusively in the presenceof electricity. In this work, copper-doped LIG (Cu-LIG) composite electrodes and filterswere developed with enhanced antimicrobial properties in single-step laser scribing. Thework emphasizes the optimization of copper doping with LIG for both electrical and nonelectrical-based disinfection. The copper doping was optimized to a minimal concentration(∼1%) just to enhance the electrochemical properties of LIG. Furthermore, the excess additionof copper was helpful towards non-electricity-based treatment without significantleaching. The prepared surfaces were tested in both electrodes and filter configuration andshowed excellent antibacterial and antiviral activity against mixed bacterial culture and amodel enteric virus, MS2 bacteriophage. On the application of 2.5 V with Cu-LIG electrodes,6-log removal of bacteria and virus was achieved. Furthermore, the membrane-based electroconductivefilters were tested in a flow-through configuration and demonstrated 6-logremoval at 2.5 V with a flux of ∼ 500 (L·m^(2))/h with both bacteria and viruses at minimumenergy expense. Additionally, reactive oxygen species scavenging and hydrogen peroxidegeneration experiments have confirmed the role of electrical effects and indirect oxidationon the inactivation mechanism. The prepared Cu-LIG composite surfaces showed potentialfor environmental remediation applications.展开更多
Spinal cord injury(SCI)is a debilitating ailment that leads to the loss of motor and sensory functions,often leaving the patient paralyzed below the injury site(Chen et al.,2013).Globally around 250,000-300,000 people...Spinal cord injury(SCI)is a debilitating ailment that leads to the loss of motor and sensory functions,often leaving the patient paralyzed below the injury site(Chen et al.,2013).Globally around 250,000-300,000 people are diagnosed with SCI annually(Singh et al.,2014),and while this number appears quite low,the effect that an SCI has on the patient’s quality of life is drastic,due to the current difficulties to comprehensively treat this illness.The cost of patient care can also be quite costly,amounting to an estimated$1.69 billion in healthcare costs in the USA alone(Mahabaleshwarkar and Khanna,2014).展开更多
The aim of this study was to develop self-healable and robust elect roconductive film based on polyaniline copolymer for application as electrode in flexible supercapacitor.For this purpose,the electroconductive polym...The aim of this study was to develop self-healable and robust elect roconductive film based on polyaniline copolymer for application as electrode in flexible supercapacitor.For this purpose,the electroconductive polymer brushes(EPB)was elaborated.The synthesis of EPB is based on graft polymerizations of acrylamide(AAm)on poly(vinyl alcohol)(PVA)with formation of PVA-PAAm polymer brush and subsequent graft copolymerization of aniline and p-phenylenediamine on PVA-PAAm resulting in formation of EPB with electroconducting copoly(aniline-co-pphenylenediamine)(PAPh DA).It was found that the ratio between PVA and PAAm at the first stage greatly influence the electrochemical performance of the EPBs.Electroconducting films were prepared by casting of EPB solution with subsequent drying.Investigation of electrical current distribution through the film with AFM reveal more uniform distribution of PAPhDA in EPB in comparison with reference PVA-PAPhDA and PAAm-PAPhDA samples.It was demonstrated that mechanical cha racteristics and electrical conductivity values of films restore at large extent after curring and self-healing under optimal relative humidity level(58%).The flexile supercapacitor cell with EPB film electrodes demon strate specific capacitance 602 mF·cm^(-2)at the current density of 1 mA·cm^(-2)and retention 94%of initial capacitance after 5000 charge/discharge cycles.展开更多
The oxidation behavior of electroconductive TiN/O′-Sialon ceramics prepared using high titania slag as main starting material was studied at 1 200-1 300 °C in air. The isothermal and non-isothermal oxidation pro...The oxidation behavior of electroconductive TiN/O′-Sialon ceramics prepared using high titania slag as main starting material was studied at 1 200-1 300 °C in air. The isothermal and non-isothermal oxidation processes were investigated by DTA-TG. Phase compositions and morphologies of the oxidized products were analyzed by XRD, SEM and EDS. The results indicate that the oxidation of TiN and O′-Sialon occurs at about 500 °C and 1 050 °C, respectively. After oxidation at 1 200-1 300 °C, a protective scale that consists of Fe2MgTi3O10, SiO2 and TiO2 is formed on the surface of the materials, which effectively prevents the oxidation process. The formation of a protective scale is relative to TiN content and apparent porosity of the samples, the amount of SiO2 and amorphous phase in the oxidation product. At the initial oxidation stage, the oxidation kinetics of the materials follows perfectly the linear law with the apparent activation energy of 1.574×105 J/mol, and at the late-mid stage, the oxidation of the samples obeys the parabolic law with the apparent activation energy of 2.693×105 J/mol. With the increase of TiN content, mass gain of the materials increases significantly.展开更多
Polymer exchange membrane fuel cells （PEMFC） are objects of the current engineering technology and these are versatile generators for electrical energy. There are various kinds from them, but all of them are going o...Polymer exchange membrane fuel cells （PEMFC） are objects of the current engineering technology and these are versatile generators for electrical energy. There are various kinds from them, but all of them are going on work at highest temperature. There isn＇t a PEMFC which can run at room temperature, like 20 ℃. In this study there is a aim for constructing such one for alternative fuels utilisation. PS and many electroconducting polymer formulations were proved by different researchers for PEM benefications, but here PS was synthesized without containing metalic contaminants and after converted to the PEM membrane.展开更多
By oxidative polycondensation of 1-naphthol and their copolycondensation with aniline or p-phenylenediamine the polyfucntional polyconjugated oligomers consisting of hydroxynaphthylene links have been prepared. These ...By oxidative polycondensation of 1-naphthol and their copolycondensation with aniline or p-phenylenediamine the polyfucntional polyconjugated oligomers consisting of hydroxynaphthylene links have been prepared. These soluble and meltable oligomers showing thermostability, semiconducting and paramagnetic properties and also high reactivity at reactions characteristic for aromatic hydroxyl groups were used as active filler at preparation of rubbers from butyl and butadiene-nitrile rubbers. It has been shown that in partial or full substitution of carbon black by oligohydroxynaphthylenes or cooligohydroxynaphthylenephenylamines in composition of vulcanizate the prepared rubbers are characterized by noticeably high heat-physical, physical-mechanical and electrical properties （Pv = 10^8 - 10^6Om. cm ）.展开更多
A project of electrical rocket engine of the future, which operates on principle of a magnetoplasmadynamic engine, is being considered. New concept of the superconducting magnetic system, stipulating installation of e...A project of electrical rocket engine of the future, which operates on principle of a magnetoplasmadynamic engine, is being considered. New concept of the superconducting magnetic system, stipulating installation of external field winding, in which the current is directed parallel to longitudinal axis of the engine, makes it possible to increase the magnitude of the transversal magnetic field in working chamber, to decrease the rated current and to raise the engine efficiency. On the basis of equations that describe the process of converting electrical energy into mechanical energy, a mathematical model has been composed with whose help the characteristics of magnetoplasma engine having conventional design and the characteristics of the engine being developed in the project have been determined. Conducted research has shown that new design increases engine efficiency from 50% up to 91%. The project also contains a consideration of the new engine design with movable cathode and with cathode having forced cooling which helps to reduce carryover of cathode mass and to increase lifetime by several times. In conclusion, the results of calculations and constructive development of electrorocket engine for flight towards planet Jupiter, which creates tractive force of 250 N at 2500 kW power, are given.展开更多
Nd Sr2Mn2O7＋δ compounds were synthesized by ceramic method under three different cooling conditions. The Nd Sr2Mn2O7＋δ samples were characterized by powder X-ray diffraction（XRD）. Oxygen non-stoichiometry data f...Nd Sr2Mn2O7＋δ compounds were synthesized by ceramic method under three different cooling conditions. The Nd Sr2Mn2O7＋δ samples were characterized by powder X-ray diffraction（XRD）. Oxygen non-stoichiometry data for the studied powders were determined by using gravimetric and X-ray photoelectron spectroscopy（XPS） methods. The correlation of cooling method and oxygen as non-stoichiometry was established. The electroconductivity in samples was studied by using four-point probe method, and the strong correlation with non-stoichiometry was found out. Magnetization measurements were carried out. It was found that the magnetic and transport properties of the samples were also influenced by oxygen non-stoichiometry. The evolution of the magnetic properties could be explained by the formation of magnetic clusters in the vicinity of oxygen vacancies（OV） and strong competition between the superexchange and double exchange interactions.展开更多
An easy and practical system of feeble fluctuation of liquid electrical conductivity is described. The system, which increases a precision on the three orders magnitude as compared with that of the recent domestic con...An easy and practical system of feeble fluctuation of liquid electrical conductivity is described. The system, which increases a precision on the three orders magnitude as compared with that of the recent domestic conductivity meter, is used to measure the feeble fluctuation of the conductivity by means of compensation and comparison, so that it solves the problem of measuring the feeble fluctuation.展开更多
In this work, we study the stability of a class of materials obtained by printing a textile with conductive inks using a method called screen printing. Under the action of a certain external factors, the printed circu...In this work, we study the stability of a class of materials obtained by printing a textile with conductive inks using a method called screen printing. Under the action of a certain external factors, the printed circuit suffers deterioration and the conductivity decreases considerably. In this work, we propose to model the overall damage of the textile sheet in terms of the partial damages of the conductive lines. We also apply this approach to evaluate the damage of a system being made of transmission lines printed into nonwoven substrates using different conductive inks.展开更多
Specific conductivity of the composite nanomaterial layers with micron and submicron dimensions, consisting of carboxymethyl cellulose (CMC) and multiwalled carbon nanotubes (MWCNT) was investigated. Ultradispersed aq...Specific conductivity of the composite nanomaterial layers with micron and submicron dimensions, consisting of carboxymethyl cellulose (CMC) and multiwalled carbon nanotubes (MWCNT) was investigated. Ultradispersed aqueous suspension was deposited on soft (aluminum foil, plates made from polyester and polyimide, cotton fabric, office paper) and solid (coverslip, silicon wafers with silicon oxide layer) substrates by silk-screen printing. Electrical resistance was measured by four-probe method and by the method of square on surface from which the conductivity and conductivity per square of surface were calculated taking into account layer’s geometric dimensions. Specific conductivity of the layers with thickness range 0.5 - 5 μm was? ~1.2×104÷4×104 S/m, and max conductivity per square was ~ 0.2 S. Investigated nanomaterial is attractive to electronic and biomedical applications.展开更多
A technology for obtaining microlayered composite materials of Cu-Zr-Y-Mo, Cu-Zr-Y-Cr, Cu-Zr-Y-W and Cu-Zr-Y-C systems by means of high-speed electron-beam evaporation-condensation, structure, electrical, and mechanic...A technology for obtaining microlayered composite materials of Cu-Zr-Y-Mo, Cu-Zr-Y-Cr, Cu-Zr-Y-W and Cu-Zr-Y-C systems by means of high-speed electron-beam evaporation-condensation, structure, electrical, and mechanical properties at ambient and elevated temperatures is developed.展开更多
We describe theoretically the grounded method of measuring the conductivity of anisotropic layered semiconductor materials. The suggested method implies the use of a four-probe testing device with a linear arrangement...We describe theoretically the grounded method of measuring the conductivity of anisotropic layered semiconductor materials. The suggested method implies the use of a four-probe testing device with a linear arrangement of probes. The final expressions for identifying the electrical conductivity are presented in the form of a series of analytic functions. The suggested method is experimentally verified, and practical recommendations of how to apply it are also provided.展开更多
We present an interesting low-cost,green,and scalable technique for direct ink writing for flexible electronic applications different from traditional fabrication techniques.In this work,a reduced graphene oxide(RGO)‒...We present an interesting low-cost,green,and scalable technique for direct ink writing for flexible electronic applications different from traditional fabrication techniques.In this work,a reduced graphene oxide(RGO)‒bismuth oxide(Bi_(2)O_(3))/carbon nanotube(CNT)(RGBC)ternary conductive ink was prepared by an initial synthesis of RGO‒Bi_(2)O_(3)(RGB)via a hydrothermal method.This was followed by the fabrication of conductive ink through homogenous mixing of the binary nanocomposite with CNTs in a mixture of ethanol,ethylene glycol,glycerol,and double-distilled water as the solvent.Electronic circuits were fabricated through directly writing the prepared ink on flexible nanocrystalline cellulose(NCC)thin film substrates.The nanocomposites consisted of rod-shaped nanoparticles that were grown on the surface of the nanographene sheet.The semiconductor nanocomposite exhibited excellent conductivity and further confirmed by applying it as an electrode in the electrical circuit to light a light-emitting diode(LED)bulb.The highest electrical conductivity achieved was 2.84×10^(3)S·m^(−1)with a contact angle of 37°.The electronic circuit written using the conductive ink exhibited good homogeneity,uniformity,and adhesion.The LED experiment demonstrates the good conductivity of the electroconductive circuit and prepared ink.Hence,the NCC substrate and RGBC conductive ink showcase an excellent potential for flexible electronic applications.展开更多
The interrelated side reactions and dendrites growth severely destabilize the electrode/electrolyte interfaces,resulting in the difficult application of aqueous Zn ion batteries(AZIBs).Hydrophobic protective layer pos...The interrelated side reactions and dendrites growth severely destabilize the electrode/electrolyte interfaces,resulting in the difficult application of aqueous Zn ion batteries(AZIBs).Hydrophobic protective layer possesses natural inhibition ability for side reactions.However,the conventional protective layer with plane structure is difficult to attain joint regulation of side reaction and Zn nucleation.Herein,a novel three-dimensional(3D)electrically conductive and hydrophobic(3DECH)interface is elaborated to enable stable Zn anode.The as-prepared 3DECHinterface presents a uniform 3Dmorphologywith hydrophobic property,large specific surface area,abundant zincophilic sites,and excellent electroconductivity.Therefore,the 3DECH interface achieves uniform nucleation and dendrite-free deposition from synergetic benefits:(1)increased nucleation sites and reduced local current density through the special 3D structure and(2)uniform electric potential distribution and rapid Zn^(2+)transport due to the electroconductive alloy chemistry,thus coupling the hydrophobic property to obtain a highly reversible Zn anode.Consequently,the modified anode achieves a superior coulombic efficiency of 99.88%over 3500 cycles,and the pouch cells using modified anode and LiMn_(2)O_(4)(LMO)cathode retain a capacity of 84 mAh g^(−1)after 700 cycles at a reasonable depth discharge of 36%,without dendrite piercing and“dead Zn.”展开更多
To achieve lightweight B_(4)C-based composite ceramics with high electrical conductivities and hardness,B_(4)C-TiB_(2) ceramics were fabricated by reactive spark plasma sintering(SPS)using B_(4)C,TiC,and amorphous B a...To achieve lightweight B_(4)C-based composite ceramics with high electrical conductivities and hardness,B_(4)C-TiB_(2) ceramics were fabricated by reactive spark plasma sintering(SPS)using B_(4)C,TiC,and amorphous B as raw materials.During the sintering process,fine B_(4)C-TiB_(2) composite particles are firstly in situ synthesized by the reaction between TiC and B.Then,large raw B_(4)C particles tend to grow at the cost of small B_(4)C particles.Finally,small TiB_(2) grains surround large B_(4)C grains to create a three-dimensional interconnected intergranular TiB_(2) network,which is beneficial for an electro-conductive network and greatly improves the conductivity of the ceramics.The effect of the B_(4)C particle size on the mechanical and electrical properties of the ceramics was investigated.When the particle size of initial B_(4)C powders is 10.29µm,the obtained B_(4)C-15 vol%TiB_(2) composite ceramics exhibit an electrical conductivity as high as 2.79×10^(4) S/m and a density as low as 2.782 g/cm^(3),together with excellent mechanical properties including flexural strength,Vickers hardness(HV),and fracture toughness(KIC)of 676 MPa,28.89 GPa,and 5.28 MPa·m^(1/2),respectively.展开更多
Over the years,electroconductive hydrogels(ECHs)have been extensively applied for stimulating nerve regeneration and restoring locomotor function after peripheral nerve injury(PNI)with diabetes,given their favorable m...Over the years,electroconductive hydrogels(ECHs)have been extensively applied for stimulating nerve regeneration and restoring locomotor function after peripheral nerve injury(PNI)with diabetes,given their favorable mechanical and electrical properties identical to endogenous nerve tissue.Nevertheless,PNI causes the loss of locomotor function and inflammatory pain,especially in diabetic patients.It has been established that bone marrow stem cells-derived exosomes(BMSCs-Exos)have analgesic,anti-inflammatory and tissue regeneration properties.Herein,we designed an ECH loaded with BMSCs-Exos(ECH-Exos)electroconductive nerve dressing to treat diabetic PNI to achieve functional recovery and pain relief.Given its potent adhesive and self-healing properties,this laminar dressing is convenient for the treatment of damaged nerve fibers by automatically wrapping around them to form a size-matched tube-like structure,avoiding the cumbersome implantation process.Our in vitro studies showed that ECH-Exos could facilitate the attachment and migration of Schwann cells.Meanwhile,Exos in this system could modulate M2 macrophage polarization via the NF-κB pathway,thereby attenuating inflammatory pain in diabetic PNI.Additionally,ECH-Exos enhanced myelinated axonal regeneration via the MEK/ERK pathway in vitro and in vivo,consequently ameliorating muscle denervation atrophy and further promoting functional restoration.Our findings suggest that the ECH-Exos system has huge prospects for nerve regeneration,functional restoration and pain relief in patients with diabetic PNI.展开更多
As the anode material of lithium-ion battery,silicon-based materials have a high theoretical capacity,but their volume changes greatly in the charging and discharging process.To ameliorate the volume expansion issue o...As the anode material of lithium-ion battery,silicon-based materials have a high theoretical capacity,but their volume changes greatly in the charging and discharging process.To ameliorate the volume expansion issue of silicobased anode materials,g-C_(3)N_(4)/Si nanocomposites are prepared by using the magnesium thermal reduction technique.It is well known that g-C_(3)N_(4)/Si nanocomposites can not only improve the electronic transmission ability,but also ameliorate the physical properties of the material for adapting the stress and strain caused by the volume expansion of silicon in the lithiation and delithiation process.When g-C_(3)N_(4)/Si electrode is evaluated,the initial discharge capacity of g-C_(3)N_(4)/Si nanocomposites is as high as 1033.3 mAh/g at 0.1 A/g,and its reversible capacity is maintained at 548 mAh/g after 400 cycles.Meanwhile,the improved rate capability is achieved with a relatively high reversible specific capacity of 218 mAh/g at 2.0 A/g.The superior lithium storage performances benefit from the unique g-C_(3)N_(4)/Si nanostructure,which improves electroconductivity,reduces volume expansion,and accelerates lithiumion transmission compared to pure silicon.展开更多
Conductive scaffolds have been shown to exert a therapeutic effect on patients suffering from peripheral nerve injuries(PNIs).However,conventional conductive conduits are made of rigid structures and have limited appl...Conductive scaffolds have been shown to exert a therapeutic effect on patients suffering from peripheral nerve injuries(PNIs).However,conventional conductive conduits are made of rigid structures and have limited applications for impaired diabetic patients due to their mechanical mismatch with neural tissues and poor plasticity.We propose the development of biocompatible electroconductive hydrogels(ECHs)that are identical to a surgical dressing in this study.Based on excellent adhesive and self-healing properties,the thin film-like dressing can be easily attached to the injured nerve fibers,automatically warps a tubular structure without requiring any invasive techniques.The ECH offers an intimate and stable electrical bridge coupling with the electrogenic nerve tissues.The in vitro experiments indicated that the ECH promoted the migration and adhesion of the Schwann cells.Furthermore,the ECH facilitated axonal regeneration and remyelination in vitro and in vivo through the MEK/ERK pathway,thus preventing muscle denervation atrophy while retaining functional recovery.The results of this study are likely to facilitate the development of non-invasive treatment techniques for PNIs in diabetic patients utilizing electroconductive hydrogels.展开更多
文摘Electroconductive hydroxy-sodalite/graphite composites were synthesized by alkali-activation of kaolinite in the presence of sodium hydroxide as the alkali activator and graphite as a conductive filler. Thermal, morphological and microstructural properties in addition to direct current (D.C.) conductivity of the prepared composites were investigated. Thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy in the attenuated total reflection mode (FTIR/ATR), X-ray diffraction (XRD), scanning electron microscope/energy dispersive using X-ray analysis (SEM/EDX) and DC conductivity measurements were used to characterize the prepared composites. The effect of the hydroxyl-sodalite-to-graphite and NaOH-to-kaolinite ratios on the electrical conductivity was investigated and evaluated on the generated composite specimens made of Jordanian kaolinite or pure kaolinite. It was demonstrated that increasing the mass ratio of graphite-to-kaolinite in the clay-based composites increased the electrical conductivity of the resultant composites. It was also observed that using 1:1 graphite-to-pure kaolinite mass ratio showed the best electrical conductivity value of 3 × 10-3 s/cm, among the other mass ratios used for pure kaolinite specimens, while using 1:1 mass ratio of graphite-to-Jordanian kaolinite showed a conductivity of 1.6 s/cm.
基金supported by the DST(DST-WTIDST/TMD/EWO/WTI/DM/2021/283,DST-SYST,and DSTinspire faculty award)and Science and Engineering Research Board(SERB+1 种基金No.CRG/2019/005280)the Indian Institute of Technology Bombay(IITB)for their funding support for this work.ND and AMN acknowledge the Ministry of Education,India,for their doctoral fellowship support.We thank Prof.Suparna Mukherjee at IIT Bombay for kindly providing us with the host E.coli C3000(No.ATCC 15597).
文摘Waterborne pathogens pose a lifelong threat, necessitating advanced disinfection systemswith state-of-the-art materials. Laser-Induced Graphene (LIG), a 3-dimensional form ofgraphene, is a widely known electrode material for its electrically-induced antimicrobialproperties. However, LIG surfaces exhibit antimicrobial properties exclusively in the presenceof electricity. In this work, copper-doped LIG (Cu-LIG) composite electrodes and filterswere developed with enhanced antimicrobial properties in single-step laser scribing. Thework emphasizes the optimization of copper doping with LIG for both electrical and nonelectrical-based disinfection. The copper doping was optimized to a minimal concentration(∼1%) just to enhance the electrochemical properties of LIG. Furthermore, the excess additionof copper was helpful towards non-electricity-based treatment without significantleaching. The prepared surfaces were tested in both electrodes and filter configuration andshowed excellent antibacterial and antiviral activity against mixed bacterial culture and amodel enteric virus, MS2 bacteriophage. On the application of 2.5 V with Cu-LIG electrodes,6-log removal of bacteria and virus was achieved. Furthermore, the membrane-based electroconductivefilters were tested in a flow-through configuration and demonstrated 6-logremoval at 2.5 V with a flux of ∼ 500 (L·m^(2))/h with both bacteria and viruses at minimumenergy expense. Additionally, reactive oxygen species scavenging and hydrogen peroxidegeneration experiments have confirmed the role of electrical effects and indirect oxidationon the inactivation mechanism. The prepared Cu-LIG composite surfaces showed potentialfor environmental remediation applications.
基金supported by the Irish Research Council under the Government of Ireland Postdoctoral Fellowship Project ID-GOIPD/2023/1431(to AS).
文摘Spinal cord injury(SCI)is a debilitating ailment that leads to the loss of motor and sensory functions,often leaving the patient paralyzed below the injury site(Chen et al.,2013).Globally around 250,000-300,000 people are diagnosed with SCI annually(Singh et al.,2014),and while this number appears quite low,the effect that an SCI has on the patient’s quality of life is drastic,due to the current difficulties to comprehensively treat this illness.The cost of patient care can also be quite costly,amounting to an estimated$1.69 billion in healthcare costs in the USA alone(Mahabaleshwarkar and Khanna,2014).
文摘The aim of this study was to develop self-healable and robust elect roconductive film based on polyaniline copolymer for application as electrode in flexible supercapacitor.For this purpose,the electroconductive polymer brushes(EPB)was elaborated.The synthesis of EPB is based on graft polymerizations of acrylamide(AAm)on poly(vinyl alcohol)(PVA)with formation of PVA-PAAm polymer brush and subsequent graft copolymerization of aniline and p-phenylenediamine on PVA-PAAm resulting in formation of EPB with electroconducting copoly(aniline-co-pphenylenediamine)(PAPh DA).It was found that the ratio between PVA and PAAm at the first stage greatly influence the electrochemical performance of the EPBs.Electroconducting films were prepared by casting of EPB solution with subsequent drying.Investigation of electrical current distribution through the film with AFM reveal more uniform distribution of PAPhDA in EPB in comparison with reference PVA-PAPhDA and PAAm-PAPhDA samples.It was demonstrated that mechanical cha racteristics and electrical conductivity values of films restore at large extent after curring and self-healing under optimal relative humidity level(58%).The flexile supercapacitor cell with EPB film electrodes demon strate specific capacitance 602 mF·cm^(-2)at the current density of 1 mA·cm^(-2)and retention 94%of initial capacitance after 5000 charge/discharge cycles.
基金Project (2007CB613504) supported by the National Basic Research Program of ChinaProject (20070145041) supported by the Specialized Research Fund for the Doctoral Program of Higher Education, China
文摘The oxidation behavior of electroconductive TiN/O′-Sialon ceramics prepared using high titania slag as main starting material was studied at 1 200-1 300 °C in air. The isothermal and non-isothermal oxidation processes were investigated by DTA-TG. Phase compositions and morphologies of the oxidized products were analyzed by XRD, SEM and EDS. The results indicate that the oxidation of TiN and O′-Sialon occurs at about 500 °C and 1 050 °C, respectively. After oxidation at 1 200-1 300 °C, a protective scale that consists of Fe2MgTi3O10, SiO2 and TiO2 is formed on the surface of the materials, which effectively prevents the oxidation process. The formation of a protective scale is relative to TiN content and apparent porosity of the samples, the amount of SiO2 and amorphous phase in the oxidation product. At the initial oxidation stage, the oxidation kinetics of the materials follows perfectly the linear law with the apparent activation energy of 1.574×105 J/mol, and at the late-mid stage, the oxidation of the samples obeys the parabolic law with the apparent activation energy of 2.693×105 J/mol. With the increase of TiN content, mass gain of the materials increases significantly.
文摘Polymer exchange membrane fuel cells （PEMFC） are objects of the current engineering technology and these are versatile generators for electrical energy. There are various kinds from them, but all of them are going on work at highest temperature. There isn＇t a PEMFC which can run at room temperature, like 20 ℃. In this study there is a aim for constructing such one for alternative fuels utilisation. PS and many electroconducting polymer formulations were proved by different researchers for PEM benefications, but here PS was synthesized without containing metalic contaminants and after converted to the PEM membrane.
文摘By oxidative polycondensation of 1-naphthol and their copolycondensation with aniline or p-phenylenediamine the polyfucntional polyconjugated oligomers consisting of hydroxynaphthylene links have been prepared. These soluble and meltable oligomers showing thermostability, semiconducting and paramagnetic properties and also high reactivity at reactions characteristic for aromatic hydroxyl groups were used as active filler at preparation of rubbers from butyl and butadiene-nitrile rubbers. It has been shown that in partial or full substitution of carbon black by oligohydroxynaphthylenes or cooligohydroxynaphthylenephenylamines in composition of vulcanizate the prepared rubbers are characterized by noticeably high heat-physical, physical-mechanical and electrical properties （Pv = 10^8 - 10^6Om. cm ）.
文摘A project of electrical rocket engine of the future, which operates on principle of a magnetoplasmadynamic engine, is being considered. New concept of the superconducting magnetic system, stipulating installation of external field winding, in which the current is directed parallel to longitudinal axis of the engine, makes it possible to increase the magnitude of the transversal magnetic field in working chamber, to decrease the rated current and to raise the engine efficiency. On the basis of equations that describe the process of converting electrical energy into mechanical energy, a mathematical model has been composed with whose help the characteristics of magnetoplasma engine having conventional design and the characteristics of the engine being developed in the project have been determined. Conducted research has shown that new design increases engine efficiency from 50% up to 91%. The project also contains a consideration of the new engine design with movable cathode and with cathode having forced cooling which helps to reduce carryover of cathode mass and to increase lifetime by several times. In conclusion, the results of calculations and constructive development of electrorocket engine for flight towards planet Jupiter, which creates tractive force of 250 N at 2500 kW power, are given.
基金Project supported by Russian Foundation for Basic Research(12-03-00042)
文摘Nd Sr2Mn2O7＋δ compounds were synthesized by ceramic method under three different cooling conditions. The Nd Sr2Mn2O7＋δ samples were characterized by powder X-ray diffraction（XRD）. Oxygen non-stoichiometry data for the studied powders were determined by using gravimetric and X-ray photoelectron spectroscopy（XPS） methods. The correlation of cooling method and oxygen as non-stoichiometry was established. The electroconductivity in samples was studied by using four-point probe method, and the strong correlation with non-stoichiometry was found out. Magnetization measurements were carried out. It was found that the magnetic and transport properties of the samples were also influenced by oxygen non-stoichiometry. The evolution of the magnetic properties could be explained by the formation of magnetic clusters in the vicinity of oxygen vacancies（OV） and strong competition between the superexchange and double exchange interactions.
文摘An easy and practical system of feeble fluctuation of liquid electrical conductivity is described. The system, which increases a precision on the three orders magnitude as compared with that of the recent domestic conductivity meter, is used to measure the feeble fluctuation of the conductivity by means of compensation and comparison, so that it solves the problem of measuring the feeble fluctuation.
文摘In this work, we study the stability of a class of materials obtained by printing a textile with conductive inks using a method called screen printing. Under the action of a certain external factors, the printed circuit suffers deterioration and the conductivity decreases considerably. In this work, we propose to model the overall damage of the textile sheet in terms of the partial damages of the conductive lines. We also apply this approach to evaluate the damage of a system being made of transmission lines printed into nonwoven substrates using different conductive inks.
文摘Specific conductivity of the composite nanomaterial layers with micron and submicron dimensions, consisting of carboxymethyl cellulose (CMC) and multiwalled carbon nanotubes (MWCNT) was investigated. Ultradispersed aqueous suspension was deposited on soft (aluminum foil, plates made from polyester and polyimide, cotton fabric, office paper) and solid (coverslip, silicon wafers with silicon oxide layer) substrates by silk-screen printing. Electrical resistance was measured by four-probe method and by the method of square on surface from which the conductivity and conductivity per square of surface were calculated taking into account layer’s geometric dimensions. Specific conductivity of the layers with thickness range 0.5 - 5 μm was? ~1.2×104÷4×104 S/m, and max conductivity per square was ~ 0.2 S. Investigated nanomaterial is attractive to electronic and biomedical applications.
文摘A technology for obtaining microlayered composite materials of Cu-Zr-Y-Mo, Cu-Zr-Y-Cr, Cu-Zr-Y-W and Cu-Zr-Y-C systems by means of high-speed electron-beam evaporation-condensation, structure, electrical, and mechanical properties at ambient and elevated temperatures is developed.
基金Supported by the Ministry of Education and Science of the Russian Federation under Grant No 2271
文摘We describe theoretically the grounded method of measuring the conductivity of anisotropic layered semiconductor materials. The suggested method implies the use of a four-probe testing device with a linear arrangement of probes. The final expressions for identifying the electrical conductivity are presented in the form of a series of analytic functions. The suggested method is experimentally verified, and practical recommendations of how to apply it are also provided.
基金financial support from the University of KwaZulu-Natal(UKZN)Eskom Tertiary Education Support Programme(TESP)+1 种基金National Research Foundation of South Africathe UKZN Nanotechnology Platform.
文摘We present an interesting low-cost,green,and scalable technique for direct ink writing for flexible electronic applications different from traditional fabrication techniques.In this work,a reduced graphene oxide(RGO)‒bismuth oxide(Bi_(2)O_(3))/carbon nanotube(CNT)(RGBC)ternary conductive ink was prepared by an initial synthesis of RGO‒Bi_(2)O_(3)(RGB)via a hydrothermal method.This was followed by the fabrication of conductive ink through homogenous mixing of the binary nanocomposite with CNTs in a mixture of ethanol,ethylene glycol,glycerol,and double-distilled water as the solvent.Electronic circuits were fabricated through directly writing the prepared ink on flexible nanocrystalline cellulose(NCC)thin film substrates.The nanocomposites consisted of rod-shaped nanoparticles that were grown on the surface of the nanographene sheet.The semiconductor nanocomposite exhibited excellent conductivity and further confirmed by applying it as an electrode in the electrical circuit to light a light-emitting diode(LED)bulb.The highest electrical conductivity achieved was 2.84×10^(3)S·m^(−1)with a contact angle of 37°.The electronic circuit written using the conductive ink exhibited good homogeneity,uniformity,and adhesion.The LED experiment demonstrates the good conductivity of the electroconductive circuit and prepared ink.Hence,the NCC substrate and RGBC conductive ink showcase an excellent potential for flexible electronic applications.
基金Joint Funds of the National Natural Science Foundation of China,Grant/Award Number:U2130204Beijing Outstanding Young Scientists Program,Grant/Award Number:BJJWZYJH01201910007023Young Elite Scientists Sponsorship Program by CAST,Grant/Award Number:YESS20200364。
文摘The interrelated side reactions and dendrites growth severely destabilize the electrode/electrolyte interfaces,resulting in the difficult application of aqueous Zn ion batteries(AZIBs).Hydrophobic protective layer possesses natural inhibition ability for side reactions.However,the conventional protective layer with plane structure is difficult to attain joint regulation of side reaction and Zn nucleation.Herein,a novel three-dimensional(3D)electrically conductive and hydrophobic(3DECH)interface is elaborated to enable stable Zn anode.The as-prepared 3DECHinterface presents a uniform 3Dmorphologywith hydrophobic property,large specific surface area,abundant zincophilic sites,and excellent electroconductivity.Therefore,the 3DECH interface achieves uniform nucleation and dendrite-free deposition from synergetic benefits:(1)increased nucleation sites and reduced local current density through the special 3D structure and(2)uniform electric potential distribution and rapid Zn^(2+)transport due to the electroconductive alloy chemistry,thus coupling the hydrophobic property to obtain a highly reversible Zn anode.Consequently,the modified anode achieves a superior coulombic efficiency of 99.88%over 3500 cycles,and the pouch cells using modified anode and LiMn_(2)O_(4)(LMO)cathode retain a capacity of 84 mAh g^(−1)after 700 cycles at a reasonable depth discharge of 36%,without dendrite piercing and“dead Zn.”
基金supported by the National Natural Science Foundation of China (Nos.52072003 and 52002003)the University Synergy Innovation Program of Anhui Province (Nos.GXXT-2019-015 and GXXT-2020-072)the“Double-Hundred Talent Plan”of Ji’an City in Jiangxi Province (2020).
文摘To achieve lightweight B_(4)C-based composite ceramics with high electrical conductivities and hardness,B_(4)C-TiB_(2) ceramics were fabricated by reactive spark plasma sintering(SPS)using B_(4)C,TiC,and amorphous B as raw materials.During the sintering process,fine B_(4)C-TiB_(2) composite particles are firstly in situ synthesized by the reaction between TiC and B.Then,large raw B_(4)C particles tend to grow at the cost of small B_(4)C particles.Finally,small TiB_(2) grains surround large B_(4)C grains to create a three-dimensional interconnected intergranular TiB_(2) network,which is beneficial for an electro-conductive network and greatly improves the conductivity of the ceramics.The effect of the B_(4)C particle size on the mechanical and electrical properties of the ceramics was investigated.When the particle size of initial B_(4)C powders is 10.29µm,the obtained B_(4)C-15 vol%TiB_(2) composite ceramics exhibit an electrical conductivity as high as 2.79×10^(4) S/m and a density as low as 2.782 g/cm^(3),together with excellent mechanical properties including flexural strength,Vickers hardness(HV),and fracture toughness(KIC)of 676 MPa,28.89 GPa,and 5.28 MPa·m^(1/2),respectively.
基金supported by the President Foundation of Nanfang Hospital,Southern Medical University(2020C024)the Natural Science Foundation of Fujian Province(2021J011156).
文摘Over the years,electroconductive hydrogels(ECHs)have been extensively applied for stimulating nerve regeneration and restoring locomotor function after peripheral nerve injury(PNI)with diabetes,given their favorable mechanical and electrical properties identical to endogenous nerve tissue.Nevertheless,PNI causes the loss of locomotor function and inflammatory pain,especially in diabetic patients.It has been established that bone marrow stem cells-derived exosomes(BMSCs-Exos)have analgesic,anti-inflammatory and tissue regeneration properties.Herein,we designed an ECH loaded with BMSCs-Exos(ECH-Exos)electroconductive nerve dressing to treat diabetic PNI to achieve functional recovery and pain relief.Given its potent adhesive and self-healing properties,this laminar dressing is convenient for the treatment of damaged nerve fibers by automatically wrapping around them to form a size-matched tube-like structure,avoiding the cumbersome implantation process.Our in vitro studies showed that ECH-Exos could facilitate the attachment and migration of Schwann cells.Meanwhile,Exos in this system could modulate M2 macrophage polarization via the NF-κB pathway,thereby attenuating inflammatory pain in diabetic PNI.Additionally,ECH-Exos enhanced myelinated axonal regeneration via the MEK/ERK pathway in vitro and in vivo,consequently ameliorating muscle denervation atrophy and further promoting functional restoration.Our findings suggest that the ECH-Exos system has huge prospects for nerve regeneration,functional restoration and pain relief in patients with diabetic PNI.
基金the National Natural Science Foundation of China(Grant Nos.51672114 and 51603091)the Natural Science Foundation of Jiangsu Province(BK20181469)+1 种基金the Joint Open Fund of Jiangsu Collaborative Innovation Center for Ecological Building Material and Environmental Protection Equipment and Key Laboratory for Advanced Technology in Environmental Protection of Jiangsu Province,the Open Project of Key Laboratory for Ecological-Environment Materials of Jiangsu Province(JH201815)the Foundation from Marine Equipment and Technology Institute for Jiangsu University of Science and Technology,China(HZ20190004).
文摘As the anode material of lithium-ion battery,silicon-based materials have a high theoretical capacity,but their volume changes greatly in the charging and discharging process.To ameliorate the volume expansion issue of silicobased anode materials,g-C_(3)N_(4)/Si nanocomposites are prepared by using the magnesium thermal reduction technique.It is well known that g-C_(3)N_(4)/Si nanocomposites can not only improve the electronic transmission ability,but also ameliorate the physical properties of the material for adapting the stress and strain caused by the volume expansion of silicon in the lithiation and delithiation process.When g-C_(3)N_(4)/Si electrode is evaluated,the initial discharge capacity of g-C_(3)N_(4)/Si nanocomposites is as high as 1033.3 mAh/g at 0.1 A/g,and its reversible capacity is maintained at 548 mAh/g after 400 cycles.Meanwhile,the improved rate capability is achieved with a relatively high reversible specific capacity of 218 mAh/g at 2.0 A/g.The superior lithium storage performances benefit from the unique g-C_(3)N_(4)/Si nanostructure,which improves electroconductivity,reduces volume expansion,and accelerates lithiumion transmission compared to pure silicon.
基金the National Key Research and Development Program of China(2017YFA0105400)the National Natural Science Foundation of China(82072455,81772349,31470949)+1 种基金the Guangdong Basic and Applied Basic Research Foundation(2019A1515012181,2017A030313594)the Guangzhou Science and Technology Planning Project of China(201707010115).
文摘Conductive scaffolds have been shown to exert a therapeutic effect on patients suffering from peripheral nerve injuries(PNIs).However,conventional conductive conduits are made of rigid structures and have limited applications for impaired diabetic patients due to their mechanical mismatch with neural tissues and poor plasticity.We propose the development of biocompatible electroconductive hydrogels(ECHs)that are identical to a surgical dressing in this study.Based on excellent adhesive and self-healing properties,the thin film-like dressing can be easily attached to the injured nerve fibers,automatically warps a tubular structure without requiring any invasive techniques.The ECH offers an intimate and stable electrical bridge coupling with the electrogenic nerve tissues.The in vitro experiments indicated that the ECH promoted the migration and adhesion of the Schwann cells.Furthermore,the ECH facilitated axonal regeneration and remyelination in vitro and in vivo through the MEK/ERK pathway,thus preventing muscle denervation atrophy while retaining functional recovery.The results of this study are likely to facilitate the development of non-invasive treatment techniques for PNIs in diabetic patients utilizing electroconductive hydrogels.
