Effect of rare earth treatment on surface physicochemical properties of carbon fibers and interfacial properties of carbon fiber/epoxy composites was investigated, and the interfacial adhesion mechanism of treated car...Effect of rare earth treatment on surface physicochemical properties of carbon fibers and interfacial properties of carbon fiber/epoxy composites was investigated, and the interfacial adhesion mechanism of treated carbon fiber/epoxy composite was analyzed. It was found that rare earth treatment led to an increase of fiber surface roughness, improvement of oxygeaa-containing groups, and introduction of rare earth element on the carbon fiber surface. As a result, coordination linkages between fibers and rare earth, and between rare earth and resin matrix were formed separately, thereby the interlaminar shear strength (ILSS) of composites increased, which indicated the improvement of the interfacial adhesion between fibers and matrix resin resulting from the increase of carboxyl and carbonyl.展开更多
In this paper, effects of pH on the interfacial properties of heavy crude functional fractions and water system are investigated. The influence of pH on π-A isotherms of acid fraction, basic fraction, amphoteric frac...In this paper, effects of pH on the interfacial properties of heavy crude functional fractions and water system are investigated. The influence of pH on π-A isotherms of acid fraction, basic fraction, amphoteric fraction and asphaltene is great. The interfacial pressure of fractions increases in strongly basic conditions. The ζ (-80mv) of acid fraction is the largest under basic conditions (pH=11-12), with the result to show that the interfacial activity of the acid fraction is superior to that of other fractions. The results of model emulsions show that strongly basic conolition (pH≥11) is beneficial to oil-in- water emulsion stability. The interfacial activity of acid fraction and asphaltene is superior to that of other crude fractions.展开更多
Waste cooking oils and non-edible vegetable oils are abundant and renewable resources for bio-based materials which have showed great potential applications in many industries.In this study,five fatty acids commonly f...Waste cooking oils and non-edible vegetable oils are abundant and renewable resources for bio-based materials which have showed great potential applications in many industries.In this study,five fatty acids commonly found in non-edible vegetable oils,including palmitic acid,stearic acid,linoleic acid,linolenic acid,ricinoleic acid,and their mixtures,were used to produce bio-based zwitterionic surfactants through a facile and high-yield chemical modification.These surfactants demonstrated excellent surface/interfacial properties with the minimum surface tensions ranging from 28.4 mN/m to 32.8 mN/m in aqueous solutions.The interfacial tensions between crude oil and surfactant solutions were remarkably reduced to lower values ranging from 0.0028 mN/m to 0.1983 mN/m without the aid of extra alkali,which particularly implied a great potential application in enhanced oil recovery.Meanwhile,these bio-based surfactants also showed good wetting properties(contact angles of~51°comparing with that of double distilled water,92.04°)and appropriate predicted biodegradability(degradation order of“weeks”for bio-based surfactants synthesized from saturated fatty acids,and“months”for those synthesized from unsaturated fatty acids).Bio-based surfactants synthesized from unsaturated fatty acids showed better interfacial properties in reducing interfacial tension between crude oil and formation water.The bio-based surfactants presented in this study are alternative substitutes for traditional petroleum-based surfactants in various surfactant application fields.展开更多
The high performance liquid chromatography method (HPLC) with ethyl cellulose/cellulose acetate (EC/CA) blends and EC as column packing material, and small molecular weight compound as probe molecules was employed to ...The high performance liquid chromatography method (HPLC) with ethyl cellulose/cellulose acetate (EC/CA) blends and EC as column packing material, and small molecular weight compound as probe molecules was employed to measure the retention volume (VR) and equilibrium distribution coefficient (K) of both inorganic and organic solutes. The interfacial separation properties of EC/CA blends were characterized by the HPLC data. The effects of the blends on the interfacial adsorption properties, hydrophilicity, affinity, polar and non-polar parameters of EC membrane materials were studied subsequently. The research results indicate that the interfacial adsorption properties and hydrophilicity of EC have been improved by solution blending with CA. The alloys are superior to EC in the separation efficiency for non-dissociable polar organic solute. The EC/CA alloy (80:20, ω) is suitable for desalting and desaccharifying.展开更多
The interfacial property of carbon fiber(CF)reinforced composites is crucial to facilitate the application of high-strength composites.Utilizing the electrostatic and hydrogen bond properties of diazo resin,carbon nan...The interfacial property of carbon fiber(CF)reinforced composites is crucial to facilitate the application of high-strength composites.Utilizing the electrostatic and hydrogen bond properties of diazo resin,carbon nanotubes(CNTs)and graphene oxide(GO)could be quickly grafted onto the surface of the CF via the layer-by-layer self-assembly technique.The results showed that CNTs and GO were uniformly coated onto the CF surface,and the chemical activity and roughness of the modified CF surface were improved signif-icantly.The modified CF surface can significantly augment the interaction between the epoxy resin and the fiber.Remarkably,due to the good interfacial property,the impact performance of the composites re-inforced with the nanomaterial-modified CF was improved obviously.In addition,the interface properties of the composites are studied in depth.This method is expected to achieve rapid surface modification of carbon fiber.展开更多
Benzene alkylation catalyzed by immobilized ionic liquids(ILs)on solid carriers is considered as a heterogeneous reaction,in which the interfacial properties play an important role.Hence,the interfacial characteristic...Benzene alkylation catalyzed by immobilized ionic liquids(ILs)on solid carriers is considered as a heterogeneous reaction,in which the interfacial properties play an important role.Hence,the interfacial characteristics between benzene/1-dodecene mixture and immobilized chloroaluminate ILs with different alkyl chain length on the silica substrate were investigated by molecular dynamics simulation.The grafted ILs can obviously promote the enrichment of benzene near the interface,leading to a higher ratio of benzene to dodecene,and the interfacial width increases slightly with increased alkyl chain of grafted cations.At the same time,the grafted cations can also enhance the benzene diffusion and suppress the dodecene diffusion at the interface,which probably helps to inhibit the inactivation of catalysts.This work provides deeply insights into the rational design of novel immo-bilized ILs catalysts for the benzene alkylation.展开更多
Interfacial and electrical properties of HfAlO/GaSb metal-oxide-semiconductor capacitors(MOSCAPs) with sulfur passivation were investigated and the chemical mechanisms of the sulfur passivation process were carefully ...Interfacial and electrical properties of HfAlO/GaSb metal-oxide-semiconductor capacitors(MOSCAPs) with sulfur passivation were investigated and the chemical mechanisms of the sulfur passivation process were carefully studied. It was shown that the sulfur passivation treatment could reduce the interface trap density Ditof the HfAlO/GaSb interface by 35% and reduce the equivalent oxide thickness(EOT) from 8 nm to 4 nm. The improved properties are due to the removal of the native oxide layer, as was proven by x-ray photoelectron spectroscopy measurements and high-resolution cross-sectional transmission electron microscopy(HRXTEM) results. It was also found that GaSb-based MOSCAPs with HfAlO gate dielectrics have interfacial properties superior to those using HfO2 or Al2O3 dielectric layers.展开更多
It is a challenge to identify each phase in a multi-component polymer system and uniquely determine the interfacial properties between the different phases.Using atomic force microscopy nanomechanical mapping(AFM-NM)a...It is a challenge to identify each phase in a multi-component polymer system and uniquely determine the interfacial properties between the different phases.Using atomic force microscopy nanomechanical mapping(AFM-NM)and AFM-based infrared spectroscopy(AFM-IR),we identify each phase,visualize structural developments,and determine the interfacial properties in a blend of three polymers:high-density polyethylene(HDPE),polyamide(PA6)and poly(styrene-b-ethylene-co-butylene-b-styrene)(SEBS).Each phase can be identified from the Young’s modulus,along with the structural development within the phases before and after compatibilization.The interfacial widths between HDPE/PA6,HDPE/SEBS and SEBS/PA6 were determined independently in one measurement from a Young’s modulus map.The structural,mechanical property development and identity of the phases were determined by AFM-NM,while AFM-IR,providing complementary chemical information,identified interfacial reactions,showed the chemical affinity of a compatibilizer with the component phases,and mapped the distribution of the compatibilizer in the ternary polymer blends.The chemical,structural and interfacial information obtained by these measurements provide information that is essential for producing mechanically robust materials from incompatible mixtures of polymers.展开更多
This paper examined different kinds of organic functional groups that were introduced onto the surface of nano TiO_(2) by surface modification with different types of zircoaluminate coupling agents.The modified nanoTi...This paper examined different kinds of organic functional groups that were introduced onto the surface of nano TiO_(2) by surface modification with different types of zircoaluminate coupling agents.The modified nanoTiO_(2) products with different interfacial properties were obtained,and the impact of the interfacial properties of nanoTiO_(2) on the rheological behavior of paper coating and the properties of coated paper was systematically investigated.The steady shear rheological results showed that the paper coatings containing nano TiO_(2) exhibited a pseudoplastic fluid behavior,characterized as obvious shear thinning.Compared to the hydrophilic unmodified nano TiO_(2),modified nano TiO_(2) could contribute more to the viscosity of paper coatings.The study on the dynamic viscoelasticity revealed that,through the enhancing action among each component in paper coatings,the modified nano TiO_(2) with quaternary amine groups or carboxyl led to a higher dynamic elastic storage modulus and viscous loss modulus of paper coatings.In addition,SEM and AFM analyses indicated that adding modified nano TiO_(2) products in paper coating could improve the coating structure,thus ameliorating the optical properties and printability of coated paper.The results obtained could provide a good reference for the application of nano pigments in paper coating.展开更多
We use a Monte Carlo method to study the phase and interracial behaviors of A-b-B diblocks in a blend of homopolymers, A and B, which are confined between two asymmetric hard and impenetrable walls. Our results show t...We use a Monte Carlo method to study the phase and interracial behaviors of A-b-B diblocks in a blend of homopolymers, A and B, which are confined between two asymmetric hard and impenetrable walls. Our results show that, when the interaction strength is weak, the block copolymers are uniformly distributed in the ternary mixtures under considered concentrations. Under strong interaction strength, distribution region of the block copolymers changes from a single smooth interface to a curved interface or multi-layer interface in the ternary mixtures. Furthermore, our findings show that with increasing volume fraction of A-b-B diblock copolymer (φc), copolymer profiles broaden while φc ≥ 0.4, a lamellar phase is formed and by further increasing φc, more thinner layers are observed. Moreover, the results show that, with the increase of φc, the phase interface first gradually transforms from plane to a curved surface rather than micelle or lamellar phase while with the increase of the interaction between A and B segments (CAB), the copolymer chains not only get stretched in the direction perpendicular to the interface, but also are oriented. The simulations also reveal that the difference between symmetric and asymmetric copolymers is negligible in statistics if the lengths of two blocks are comparable.展开更多
This study shows that the mechanical strength of the composite of Fe matrix and titanium carbide(Ti C)ceramic particles is significantly enhanced with addition of molybdenum(Mo) atoms. Ti C reinforced Fe(Fe-0.2C-7Mn) ...This study shows that the mechanical strength of the composite of Fe matrix and titanium carbide(Ti C)ceramic particles is significantly enhanced with addition of molybdenum(Mo) atoms. Ti C reinforced Fe(Fe-0.2C-7Mn) composites with and without Mo were fabricated by a liquid pressing infiltration(LPI)process and the effect of Mo on interfacial properties of TiC–Fe composite was investigated using atomic probe tomography(APT) analysis, molecular dynamics(MD) simulations, first-principle density functional theory(DFT), and thermodynamic calculations. First, DFT calculations showed that total energies of the Mo-doped Ti C–Fe superlattices strongly depend on the position of Mo defects, and are minimized when the Mo atom is located at the TiC/Fe interface, supporting the probable formation of MoC-like interphase at the TiC/Fe interface region. Then, APT analysis confirmed the DFT predictions by finding that about6.5 wt.% Mo is incorporated in the Ti C–Fe(Mo) composite and that sub-micrometer thick(Ti,Mo)C interphase is indeed formed near the interface. The MD simulations show that Mo atoms migrate to the Mo-free TiC–Fe interface at elevated temperatures and the mechanical strength of the interface is considerably enhanced, which is in good agreement with experimental observations.展开更多
A comparison study on interfacial properties of a traditional fluorine-bearing(F-bearing)mold flux and a newly designed fluorine-free(F-free)mold flux to produce advanced high-strength steels(AHSSs)by compact strip pr...A comparison study on interfacial properties of a traditional fluorine-bearing(F-bearing)mold flux and a newly designed fluorine-free(F-free)mold flux to produce advanced high-strength steels(AHSSs)by compact strip production technology was conducted.The results showed that these two kinds of mold fluxes gradually spread out on the typical AHSS substrate when slags began to melt with the increase in heating temperature,and they had a good interfacial ability between the two mold fluxes and the AHSS substrate,and there was no other interfacial reaction except the oxidization of steel substrate by the mold fluxes.In comparison,the wettability of the designed F-free mold flux with the AHSS substrate was better than that of the F-bearing mold flux.The reason could be explained as the addition of B_(2)O_(3) would increase the complexity and polymerization degree of the melt structure and weaken the attractive force between the ions and ionic groups,then leading to a better wettability.Besides,B_(2)O_(3) is an effective flux,which can reduce the melting temperature obviously,and the surface tension of the liquid F-free mold flux would get reduced with the addition of B_(2)O_(3).展开更多
The ZrTiON gate-dielectric GaAs metal-oxide-semiconductor (MOS) capacitors with or without ZrAION as the interfacial passivation layer (IPL) are fabricated and their properties are investigated. The experimental r...The ZrTiON gate-dielectric GaAs metal-oxide-semiconductor (MOS) capacitors with or without ZrAION as the interfacial passivation layer (IPL) are fabricated and their properties are investigated. The experimental results show that the GaAs MOS capacitor with the ZrAION IPL exhibits better interracial and electrical properties, including lower interface-state density (1.14 × 10^12 cm^-2eV^-1), smaller gate leakage current (6.82 × 10^-5 A//cm^2 at Vfb +1V), smaller capacitance equivalent thickness (1.5 nm), and larger k value (26). The involved mechanisms lie in the fact that the ZrAION IPL can effectively block the diffusion of Ti and O towards the GaAs surface, thus suppressing the formation of interracial Ga-/As-oxides and As-As dimers, which leads to improved interracial and electrical properties for the devices.展开更多
In the present study, pure iron/copper composite metal cladding was deposited onto carbon steel by tungsten inert gas welding. The study focused on interfacial morphological, microstructural, and mechanical analyses o...In the present study, pure iron/copper composite metal cladding was deposited onto carbon steel by tungsten inert gas welding. The study focused on interfacial morphological, microstructural, and mechanical analyses of the composite cladding layers. Iron liquid–solid-phase zones were formed at copper/steel and iron interfaces because of the melting of the steel substrate and iron. Iron concentrated in the copper cladding layer was observed to exhibit belt, globule, and dendrite morphologies. The appearance of iron-rich globules indicated the occurrence of liquid phase separation(LPS) prior to solidification, and iron-rich dendrites crystallized without the occurrence of LPS. The maximum microhardness of the iron/steel interface was lower than that of the copper/steel interface because of the diffusion of elemental carbon. All samples fractured in the cladding layers. Because of a relatively lower strength of the copper layer, a short plateau region appeared when shear movement was from copper to iron.展开更多
The feasibility of using coral reef sand(CRS) in Portland cement concrete is investigated by testing the mechanical property and microstructure of concrete. The composition, structure and properties of the CRS are a...The feasibility of using coral reef sand(CRS) in Portland cement concrete is investigated by testing the mechanical property and microstructure of concrete. The composition, structure and properties of the CRS are analyzed. Mechanical properties and microstructure of concrete with CRS are studied and compared to concrete with natural river sand. The relationship between the microstructure and performance of CRS concrete is established. The CRS has a porous surface with high water intake capacity, which contributes to the mechanical properties of concrete. The interfacial transition zone between the cement paste and CRS is densified compared to normal concrete with river sand. Hydration products form in the pore space of CRS and interlock with the matrix of cement paste, which increases the strength. The total porosity of concrete prepared with CRS is higher than that with natural sand. The main difference in pore size distribution is the fraction of fine pores in the range of 100 nm.展开更多
We report a simple and effective method to realize desirable interfacial property for inverted planar perovskite solar cells(PSCs)by using small molecule ethanediamine for the construction of a novel polyelectrolyte h...We report a simple and effective method to realize desirable interfacial property for inverted planar perovskite solar cells(PSCs)by using small molecule ethanediamine for the construction of a novel polyelectrolyte hole transport material(P3CT-ED HTM).It is found that P3CT-ED can not only improve the hole transport property of P3CT-K but also improve the crystallinity of adjacent perovskite film.In addition,the introduction of ethanediamine into P3CT realigns the conduction and valence bands upwards,passivates surface defects and reduces nonradiative recombination.As a consequence,compared to P3CT-K hole transport layer(HTL)based devices,the average power conversion efficiency(PCE)is boosted from17.2% to 19.6% for the counterparts with P3CT-ED,with simultaneous enhancement in open circuit voltage and fill factor.The resultant device displays a champion PCE of 20.5% with negligible hysteresis.展开更多
Chloride diffusion coefficient and water penetration depth of 3 types concrete were studied. The experimental results show that the concrete permeability decreases itself in the order as follow: pure portland cement c...Chloride diffusion coefficient and water penetration depth of 3 types concrete were studied. The experimental results show that the concrete permeability decreases itself in the order as follow: pure portland cement concrete(CO), concrete added with fly ash(C1), concrete added with both fly ash and silica fume(C2). SEM and microhardness analyses show that the properties of interfacial zone are significantly influenced by silica fume. With the improvement of interfacial zone properties, the permeability especially the Chloride ion diffusivity of concrete significantly decreases.展开更多
We investigated mechanical properties of concretes made with impurity aggregates of different combinations. Besides the mechanisms were explored by EDS, CT, and hardness testing. The results showed that fully rust-sta...We investigated mechanical properties of concretes made with impurity aggregates of different combinations. Besides the mechanisms were explored by EDS, CT, and hardness testing. The results showed that fully rust-stained and surface rust-stained sandstone aggregate had significant adverse impact on the compressive strength of concrete while sandstone aggregate had a much more obvious impact on the ultimate tension of concrete. Concrete crack was more prone to expand along surfaces and the micro-hardness of interfacial transition zone of different aggregates was ranked in decreasing trend as sandstone, slate, SR sandstone, marble, and FR sandstone. The cluster growth of long needle-like ettringite crystal and strong preferential growth trend of Ca(OH)2 crystals would result in wider interfacial transition zone range of concretes made with fully rust-stained sandstone and marble aggregate, respectively. Therefore, the impurity aggregate content should be strictly controlled during aggregate selection.展开更多
The modulation of electrical properties of MoS_2 has attracted extensive research interest because of its potential applications in electronic and optoelectronic devices.Herein,interfacial charge transfer induced elec...The modulation of electrical properties of MoS_2 has attracted extensive research interest because of its potential applications in electronic and optoelectronic devices.Herein,interfacial charge transfer induced electronic property tuning of MoS_2 are investigated by in situ ultraviolet photoelectron spectroscopy and x-ray photoelectron spectroscopy measurements.A downward band-bending of MoS_2-related electronic states along with the decreasing work function,which are induced by the electron transfer from Cs overlayers to MoS_2,is observed after the functionalization of MoS_2 with Cs,leading to n-type doping.Meanwhile,when MoS_2 is modified with 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane(F_4-TCNQ),an upward band-bending of MoS_2-related electronic states along with the increasing work function is observed at the interfaces.This is attributed to the electron depletion within MoS_2 due to the strong electron withdrawing property of F_4-TCNQ,indicating p-type doping of MoS_2.Our findings reveal that surface transfer doping is an effective approach for electronic property tuning of MoS_2 and paves the way to optimize its performance in electronic and optoelectronic devices.展开更多
The effective conductivity of graphene-based nanocomposites is suggested by the characteristics of polymer-filler interfacial areas as well as the contact resistance between the neighboring nanosheets.The interfacial ...The effective conductivity of graphene-based nanocomposites is suggested by the characteristics of polymer-filler interfacial areas as well as the contact resistance between the neighboring nanosheets.The interfacial properties are expressed by the effective levels of the inverse aspect ratio and the filler volume fraction.Moreover,the resistances of components in the contact regions are used to define the contact resistance,which inversely affects the effective conductivity.The obtained model is utilized to predict the effective conductivity for some examples.The discrepancy of the effective conductivity at various ranks of all factors is clarified.The interfacial conductivity directly controls the effective conductivity,while the filler conductivity plays a dissimilar role in the effective conductivity,due to the incomplete interfacial adhesion.A high operative conductivity is also achieved by small contact distances and high interfacial properties.Additionally,big contact diameters and little tunnel resistivity decrease the contact resistance,thus enhancing the effective conductivity.展开更多
基金Project supported by the National Natural Science Foundation of China (50333030)
文摘Effect of rare earth treatment on surface physicochemical properties of carbon fibers and interfacial properties of carbon fiber/epoxy composites was investigated, and the interfacial adhesion mechanism of treated carbon fiber/epoxy composite was analyzed. It was found that rare earth treatment led to an increase of fiber surface roughness, improvement of oxygeaa-containing groups, and introduction of rare earth element on the carbon fiber surface. As a result, coordination linkages between fibers and rare earth, and between rare earth and resin matrix were formed separately, thereby the interlaminar shear strength (ILSS) of composites increased, which indicated the improvement of the interfacial adhesion between fibers and matrix resin resulting from the increase of carboxyl and carbonyl.
文摘In this paper, effects of pH on the interfacial properties of heavy crude functional fractions and water system are investigated. The influence of pH on π-A isotherms of acid fraction, basic fraction, amphoteric fraction and asphaltene is great. The interfacial pressure of fractions increases in strongly basic conditions. The ζ (-80mv) of acid fraction is the largest under basic conditions (pH=11-12), with the result to show that the interfacial activity of the acid fraction is superior to that of other fractions. The results of model emulsions show that strongly basic conolition (pH≥11) is beneficial to oil-in- water emulsion stability. The interfacial activity of acid fraction and asphaltene is superior to that of other crude fractions.
基金supported by the National Key Research and Development Program of China(No.2017YFB0308900)National Natural Science Foundation of China(Grant No.51574125)+1 种基金the Fundamental Research Funds for the Central Universities of China(No.50321101917017)the Research Program of State Key Laboratory of Bioreactor Engineering.
文摘Waste cooking oils and non-edible vegetable oils are abundant and renewable resources for bio-based materials which have showed great potential applications in many industries.In this study,five fatty acids commonly found in non-edible vegetable oils,including palmitic acid,stearic acid,linoleic acid,linolenic acid,ricinoleic acid,and their mixtures,were used to produce bio-based zwitterionic surfactants through a facile and high-yield chemical modification.These surfactants demonstrated excellent surface/interfacial properties with the minimum surface tensions ranging from 28.4 mN/m to 32.8 mN/m in aqueous solutions.The interfacial tensions between crude oil and surfactant solutions were remarkably reduced to lower values ranging from 0.0028 mN/m to 0.1983 mN/m without the aid of extra alkali,which particularly implied a great potential application in enhanced oil recovery.Meanwhile,these bio-based surfactants also showed good wetting properties(contact angles of~51°comparing with that of double distilled water,92.04°)and appropriate predicted biodegradability(degradation order of“weeks”for bio-based surfactants synthesized from saturated fatty acids,and“months”for those synthesized from unsaturated fatty acids).Bio-based surfactants synthesized from unsaturated fatty acids showed better interfacial properties in reducing interfacial tension between crude oil and formation water.The bio-based surfactants presented in this study are alternative substitutes for traditional petroleum-based surfactants in various surfactant application fields.
基金Supported by Key Scientific Research Projects of Anhui Province (No 05021026)
文摘The high performance liquid chromatography method (HPLC) with ethyl cellulose/cellulose acetate (EC/CA) blends and EC as column packing material, and small molecular weight compound as probe molecules was employed to measure the retention volume (VR) and equilibrium distribution coefficient (K) of both inorganic and organic solutes. The interfacial separation properties of EC/CA blends were characterized by the HPLC data. The effects of the blends on the interfacial adsorption properties, hydrophilicity, affinity, polar and non-polar parameters of EC membrane materials were studied subsequently. The research results indicate that the interfacial adsorption properties and hydrophilicity of EC have been improved by solution blending with CA. The alloys are superior to EC in the separation efficiency for non-dissociable polar organic solute. The EC/CA alloy (80:20, ω) is suitable for desalting and desaccharifying.
基金This work was financially supported by the National Nat-ural Science Foundation of China(Grant Nos.52072193 and U22A20131)the Shandong Provincial Natural Science Foundation(Grant Nos.ZR2021JQ16 and ZR2019YQ19)+2 种基金the Project of Shan-dong Province Higher Educational Science and Technology Program(Grant No.2019KJA026)the State Key Laboratory for Modification of Chemical Fibers and Polymer Materials(Grant No.KF2217)the Science Fund of Shandong Laboratory of Yantai Advanced Materials and Green Manufacturing(Grant No.AMGM2021F11).
文摘The interfacial property of carbon fiber(CF)reinforced composites is crucial to facilitate the application of high-strength composites.Utilizing the electrostatic and hydrogen bond properties of diazo resin,carbon nanotubes(CNTs)and graphene oxide(GO)could be quickly grafted onto the surface of the CF via the layer-by-layer self-assembly technique.The results showed that CNTs and GO were uniformly coated onto the CF surface,and the chemical activity and roughness of the modified CF surface were improved signif-icantly.The modified CF surface can significantly augment the interaction between the epoxy resin and the fiber.Remarkably,due to the good interfacial property,the impact performance of the composites re-inforced with the nanomaterial-modified CF was improved obviously.In addition,the interface properties of the composites are studied in depth.This method is expected to achieve rapid surface modification of carbon fiber.
基金The financial support by State Key Laboratory of Heavy Oil Processing
文摘Benzene alkylation catalyzed by immobilized ionic liquids(ILs)on solid carriers is considered as a heterogeneous reaction,in which the interfacial properties play an important role.Hence,the interfacial characteristics between benzene/1-dodecene mixture and immobilized chloroaluminate ILs with different alkyl chain length on the silica substrate were investigated by molecular dynamics simulation.The grafted ILs can obviously promote the enrichment of benzene near the interface,leading to a higher ratio of benzene to dodecene,and the interfacial width increases slightly with increased alkyl chain of grafted cations.At the same time,the grafted cations can also enhance the benzene diffusion and suppress the dodecene diffusion at the interface,which probably helps to inhibit the inactivation of catalysts.This work provides deeply insights into the rational design of novel immo-bilized ILs catalysts for the benzene alkylation.
基金Project supported by the National Basic Research Program of China (Grant No. 201 ICBA00602) and the National Science and Technology Major Project, China (Grant No. 2011 ZX02708-002).
文摘Interfacial and electrical properties of HfAlO/GaSb metal-oxide-semiconductor capacitors(MOSCAPs) with sulfur passivation were investigated and the chemical mechanisms of the sulfur passivation process were carefully studied. It was shown that the sulfur passivation treatment could reduce the interface trap density Ditof the HfAlO/GaSb interface by 35% and reduce the equivalent oxide thickness(EOT) from 8 nm to 4 nm. The improved properties are due to the removal of the native oxide layer, as was proven by x-ray photoelectron spectroscopy measurements and high-resolution cross-sectional transmission electron microscopy(HRXTEM) results. It was also found that GaSb-based MOSCAPs with HfAlO gate dielectrics have interfacial properties superior to those using HfO2 or Al2O3 dielectric layers.
基金by the National Natural Science Foundation of China(No.51673016)the Beijing Advanced Innovation Center for Soft matter Science and Engineering.
文摘It is a challenge to identify each phase in a multi-component polymer system and uniquely determine the interfacial properties between the different phases.Using atomic force microscopy nanomechanical mapping(AFM-NM)and AFM-based infrared spectroscopy(AFM-IR),we identify each phase,visualize structural developments,and determine the interfacial properties in a blend of three polymers:high-density polyethylene(HDPE),polyamide(PA6)and poly(styrene-b-ethylene-co-butylene-b-styrene)(SEBS).Each phase can be identified from the Young’s modulus,along with the structural development within the phases before and after compatibilization.The interfacial widths between HDPE/PA6,HDPE/SEBS and SEBS/PA6 were determined independently in one measurement from a Young’s modulus map.The structural,mechanical property development and identity of the phases were determined by AFM-NM,while AFM-IR,providing complementary chemical information,identified interfacial reactions,showed the chemical affinity of a compatibilizer with the component phases,and mapped the distribution of the compatibilizer in the ternary polymer blends.The chemical,structural and interfacial information obtained by these measurements provide information that is essential for producing mechanically robust materials from incompatible mixtures of polymers.
基金The authors extend a sincere acknowledge and appreciation for the financial support from the National Natural Science Foundation of China(Grant No.21306216,and Grant No.31470609)。
文摘This paper examined different kinds of organic functional groups that were introduced onto the surface of nano TiO_(2) by surface modification with different types of zircoaluminate coupling agents.The modified nanoTiO_(2) products with different interfacial properties were obtained,and the impact of the interfacial properties of nanoTiO_(2) on the rheological behavior of paper coating and the properties of coated paper was systematically investigated.The steady shear rheological results showed that the paper coatings containing nano TiO_(2) exhibited a pseudoplastic fluid behavior,characterized as obvious shear thinning.Compared to the hydrophilic unmodified nano TiO_(2),modified nano TiO_(2) could contribute more to the viscosity of paper coatings.The study on the dynamic viscoelasticity revealed that,through the enhancing action among each component in paper coatings,the modified nano TiO_(2) with quaternary amine groups or carboxyl led to a higher dynamic elastic storage modulus and viscous loss modulus of paper coatings.In addition,SEM and AFM analyses indicated that adding modified nano TiO_(2) products in paper coating could improve the coating structure,thus ameliorating the optical properties and printability of coated paper.The results obtained could provide a good reference for the application of nano pigments in paper coating.
基金supported by the National Natural Science Foundation of China(Nos.21304097,21334007and 21674113)
文摘We use a Monte Carlo method to study the phase and interracial behaviors of A-b-B diblocks in a blend of homopolymers, A and B, which are confined between two asymmetric hard and impenetrable walls. Our results show that, when the interaction strength is weak, the block copolymers are uniformly distributed in the ternary mixtures under considered concentrations. Under strong interaction strength, distribution region of the block copolymers changes from a single smooth interface to a curved interface or multi-layer interface in the ternary mixtures. Furthermore, our findings show that with increasing volume fraction of A-b-B diblock copolymer (φc), copolymer profiles broaden while φc ≥ 0.4, a lamellar phase is formed and by further increasing φc, more thinner layers are observed. Moreover, the results show that, with the increase of φc, the phase interface first gradually transforms from plane to a curved surface rather than micelle or lamellar phase while with the increase of the interaction between A and B segments (CAB), the copolymer chains not only get stretched in the direction perpendicular to the interface, but also are oriented. The simulations also reveal that the difference between symmetric and asymmetric copolymers is negligible in statistics if the lengths of two blocks are comparable.
基金financially supported by the Fundamental Research Program (PNK7480) of the Korea Institute of Materials Science (KIMS)the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) (NRF2020M3H4A3105943)+1 种基金supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF)funded by the Ministry of Education (NRF2014R1A1A2059123)。
文摘This study shows that the mechanical strength of the composite of Fe matrix and titanium carbide(Ti C)ceramic particles is significantly enhanced with addition of molybdenum(Mo) atoms. Ti C reinforced Fe(Fe-0.2C-7Mn) composites with and without Mo were fabricated by a liquid pressing infiltration(LPI)process and the effect of Mo on interfacial properties of TiC–Fe composite was investigated using atomic probe tomography(APT) analysis, molecular dynamics(MD) simulations, first-principle density functional theory(DFT), and thermodynamic calculations. First, DFT calculations showed that total energies of the Mo-doped Ti C–Fe superlattices strongly depend on the position of Mo defects, and are minimized when the Mo atom is located at the TiC/Fe interface, supporting the probable formation of MoC-like interphase at the TiC/Fe interface region. Then, APT analysis confirmed the DFT predictions by finding that about6.5 wt.% Mo is incorporated in the Ti C–Fe(Mo) composite and that sub-micrometer thick(Ti,Mo)C interphase is indeed formed near the interface. The MD simulations show that Mo atoms migrate to the Mo-free TiC–Fe interface at elevated temperatures and the mechanical strength of the interface is considerably enhanced, which is in good agreement with experimental observations.
基金The financial support from National Natural Science Foundation of China(U1760202)Hunan Scientific Technology projects(2020WK2003)is greatly acknowledged.
文摘A comparison study on interfacial properties of a traditional fluorine-bearing(F-bearing)mold flux and a newly designed fluorine-free(F-free)mold flux to produce advanced high-strength steels(AHSSs)by compact strip production technology was conducted.The results showed that these two kinds of mold fluxes gradually spread out on the typical AHSS substrate when slags began to melt with the increase in heating temperature,and they had a good interfacial ability between the two mold fluxes and the AHSS substrate,and there was no other interfacial reaction except the oxidization of steel substrate by the mold fluxes.In comparison,the wettability of the designed F-free mold flux with the AHSS substrate was better than that of the F-bearing mold flux.The reason could be explained as the addition of B_(2)O_(3) would increase the complexity and polymerization degree of the melt structure and weaken the attractive force between the ions and ionic groups,then leading to a better wettability.Besides,B_(2)O_(3) is an effective flux,which can reduce the melting temperature obviously,and the surface tension of the liquid F-free mold flux would get reduced with the addition of B_(2)O_(3).
基金Supported by the National Natural Science Foundation of China under Grant Nos 61176100,61274112 and 61404055
文摘The ZrTiON gate-dielectric GaAs metal-oxide-semiconductor (MOS) capacitors with or without ZrAION as the interfacial passivation layer (IPL) are fabricated and their properties are investigated. The experimental results show that the GaAs MOS capacitor with the ZrAION IPL exhibits better interracial and electrical properties, including lower interface-state density (1.14 × 10^12 cm^-2eV^-1), smaller gate leakage current (6.82 × 10^-5 A//cm^2 at Vfb +1V), smaller capacitance equivalent thickness (1.5 nm), and larger k value (26). The involved mechanisms lie in the fact that the ZrAION IPL can effectively block the diffusion of Ti and O towards the GaAs surface, thus suppressing the formation of interracial Ga-/As-oxides and As-As dimers, which leads to improved interracial and electrical properties for the devices.
基金financially supported by the National Natural Science Foundation of China (No. 51575132)
文摘In the present study, pure iron/copper composite metal cladding was deposited onto carbon steel by tungsten inert gas welding. The study focused on interfacial morphological, microstructural, and mechanical analyses of the composite cladding layers. Iron liquid–solid-phase zones were formed at copper/steel and iron interfaces because of the melting of the steel substrate and iron. Iron concentrated in the copper cladding layer was observed to exhibit belt, globule, and dendrite morphologies. The appearance of iron-rich globules indicated the occurrence of liquid phase separation(LPS) prior to solidification, and iron-rich dendrites crystallized without the occurrence of LPS. The maximum microhardness of the iron/steel interface was lower than that of the copper/steel interface because of the diffusion of elemental carbon. All samples fractured in the cladding layers. Because of a relatively lower strength of the copper layer, a short plateau region appeared when shear movement was from copper to iron.
基金Funded by the Fundamental Research Funds for the Central Universities(WUT:142201001)
文摘The feasibility of using coral reef sand(CRS) in Portland cement concrete is investigated by testing the mechanical property and microstructure of concrete. The composition, structure and properties of the CRS are analyzed. Mechanical properties and microstructure of concrete with CRS are studied and compared to concrete with natural river sand. The relationship between the microstructure and performance of CRS concrete is established. The CRS has a porous surface with high water intake capacity, which contributes to the mechanical properties of concrete. The interfacial transition zone between the cement paste and CRS is densified compared to normal concrete with river sand. Hydration products form in the pore space of CRS and interlock with the matrix of cement paste, which increases the strength. The total porosity of concrete prepared with CRS is higher than that with natural sand. The main difference in pore size distribution is the fraction of fine pores in the range of 100 nm.
基金supported by the National Natural Science Foundation of China(51672288,21975273)Taishan Scholars Program of Shandong Province,Dalian National Laboratory for Clean Energy(DICP&QIBEBT No.UN201705)+1 种基金Scientific Research Cooperation Foundation of Qingdao Institute of Bioenergy and Bioprocess TechnologyQingdao Postdoctoral Application Research Project(Project 2018183,2018186)。
文摘We report a simple and effective method to realize desirable interfacial property for inverted planar perovskite solar cells(PSCs)by using small molecule ethanediamine for the construction of a novel polyelectrolyte hole transport material(P3CT-ED HTM).It is found that P3CT-ED can not only improve the hole transport property of P3CT-K but also improve the crystallinity of adjacent perovskite film.In addition,the introduction of ethanediamine into P3CT realigns the conduction and valence bands upwards,passivates surface defects and reduces nonradiative recombination.As a consequence,compared to P3CT-K hole transport layer(HTL)based devices,the average power conversion efficiency(PCE)is boosted from17.2% to 19.6% for the counterparts with P3CT-ED,with simultaneous enhancement in open circuit voltage and fill factor.The resultant device displays a champion PCE of 20.5% with negligible hysteresis.
文摘Chloride diffusion coefficient and water penetration depth of 3 types concrete were studied. The experimental results show that the concrete permeability decreases itself in the order as follow: pure portland cement concrete(CO), concrete added with fly ash(C1), concrete added with both fly ash and silica fume(C2). SEM and microhardness analyses show that the properties of interfacial zone are significantly influenced by silica fume. With the improvement of interfacial zone properties, the permeability especially the Chloride ion diffusivity of concrete significantly decreases.
基金Funded partly by the Major State Basic Research Development Program("973"Program,Nos.2015CB655101 and 2013CB035901)the National Natural Science Foundation of China(Nos.51379163 and 51579195)
文摘We investigated mechanical properties of concretes made with impurity aggregates of different combinations. Besides the mechanisms were explored by EDS, CT, and hardness testing. The results showed that fully rust-stained and surface rust-stained sandstone aggregate had significant adverse impact on the compressive strength of concrete while sandstone aggregate had a much more obvious impact on the ultimate tension of concrete. Concrete crack was more prone to expand along surfaces and the micro-hardness of interfacial transition zone of different aggregates was ranked in decreasing trend as sandstone, slate, SR sandstone, marble, and FR sandstone. The cluster growth of long needle-like ettringite crystal and strong preferential growth trend of Ca(OH)2 crystals would result in wider interfacial transition zone range of concretes made with fully rust-stained sandstone and marble aggregate, respectively. Therefore, the impurity aggregate content should be strictly controlled during aggregate selection.
基金Supported by the National Natural Science Foundation of China (Grant No.22002031)the Natural Science Foundation of Zhejiang Province (Grant No.LY18F010019)the Innovation Project in Hangzhou for Returned Scholar。
文摘The modulation of electrical properties of MoS_2 has attracted extensive research interest because of its potential applications in electronic and optoelectronic devices.Herein,interfacial charge transfer induced electronic property tuning of MoS_2 are investigated by in situ ultraviolet photoelectron spectroscopy and x-ray photoelectron spectroscopy measurements.A downward band-bending of MoS_2-related electronic states along with the decreasing work function,which are induced by the electron transfer from Cs overlayers to MoS_2,is observed after the functionalization of MoS_2 with Cs,leading to n-type doping.Meanwhile,when MoS_2 is modified with 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane(F_4-TCNQ),an upward band-bending of MoS_2-related electronic states along with the increasing work function is observed at the interfaces.This is attributed to the electron depletion within MoS_2 due to the strong electron withdrawing property of F_4-TCNQ,indicating p-type doping of MoS_2.Our findings reveal that surface transfer doping is an effective approach for electronic property tuning of MoS_2 and paves the way to optimize its performance in electronic and optoelectronic devices.
基金Project supported by the Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education,Science and Technology(No.2022R1A2C1004437)。
文摘The effective conductivity of graphene-based nanocomposites is suggested by the characteristics of polymer-filler interfacial areas as well as the contact resistance between the neighboring nanosheets.The interfacial properties are expressed by the effective levels of the inverse aspect ratio and the filler volume fraction.Moreover,the resistances of components in the contact regions are used to define the contact resistance,which inversely affects the effective conductivity.The obtained model is utilized to predict the effective conductivity for some examples.The discrepancy of the effective conductivity at various ranks of all factors is clarified.The interfacial conductivity directly controls the effective conductivity,while the filler conductivity plays a dissimilar role in the effective conductivity,due to the incomplete interfacial adhesion.A high operative conductivity is also achieved by small contact distances and high interfacial properties.Additionally,big contact diameters and little tunnel resistivity decrease the contact resistance,thus enhancing the effective conductivity.