Infections associated with titanium(Ti)-based implants present significant challenges in clinical treatments,especially when biofilms already form on the implant surface.Many antimicrobial agents,including antibiotics...Infections associated with titanium(Ti)-based implants present significant challenges in clinical treatments,especially when biofilms already form on the implant surface.Many antimicrobial agents,including antibiotics,metallic nanoparticles and antimicrobial peptides,have been extensively used to deal with Ti implant infections.However,these chemical approaches suffer from potential toxicity,antibiotic resistance and poor long-term antibacterial performance.Hence,physical antibacterial surfaces on Ti-based implants have attracted increasing attention.The antibacterial behavior of different surfaces on Ti-based biomaterials against various bacteria only by physical properties of the implants themselves(e.g.,nanotopography)or exogenous physical stimulus(e.g.,photocatalysis)was reviewed,as well as parameters influencing the physical antibacterial processes,such as size,shape and density of the surface nanotextures,and bacterial growth phases.Besides,mechanisms of different fabrication techniques for the physical antibacterial surfaces on Ti-based biomaterials were also summarized.展开更多
Additive manufacturing(AM)has revolutionized the production of metal bone implants,enabling unprecedented levels of customization and functionality.Recent advancements in surface-modification technologies have been cr...Additive manufacturing(AM)has revolutionized the production of metal bone implants,enabling unprecedented levels of customization and functionality.Recent advancements in surface-modification technologies have been crucial in enhancing the performance and biocompatibility of implants.Through leveraging the versatility of AM techniques,particularly powder bed fusion,a range of metallic biomaterials,including stainless steel,titanium,and biodegradable alloys,can be utilized to fabricate implants tailored for craniofacial,trunk,and limb bone reconstructions.However,the potential of AM is contingent on addressing intrinsic defects that may hinder implant performance.Techniques such as sandblasting,chemical treatment,electropolishing,heat treatment,and laser technology effectively remove residual powder and improve the surface roughness of these implants.The development of functional coatings,applied via both dry and wet methods,represents a significant advancement in surface modification research.These coatings not only improve mechanical and biological interactions at the implant-bone interface but also facilitate controlled drug release and enhance antimicrobial properties.Addition-ally,micro-and nanoscale surface modifications using chemical and laser techniques can precisely sculpt implant surfaces to promote the desired cellular responses.This detailed exploration of surface engineering offers a wealth of opportunities for creating next-generation implants that are not only biocompatible but also bioactive,laying the foundation for more effective solutions in bone reconstruction.展开更多
Biodegradable metals have garnered considerable interest owing to their capacity for self-degradation following the repair of damaged tissues.This review commences with their historical development and clarifies the e...Biodegradable metals have garnered considerable interest owing to their capacity for self-degradation following the repair of damaged tissues.This review commences with their historical development and clarifies the essential prerequisites for their successful clinical translation.Subsequently,a detailed review of magnesium-based materials is presented from five critical areas of alloying,fabrication techniques,purification,surface modification,and structural design,systematically addressing their progress in biodegradation rate retardation,mechanical reinforcement,and biocompatibility enhancement.Furthermore,recent breakthroughs in vivo animal experiments and clinical translation of magnesium alloys are summarized.Finally,this review concludes with a critical assessment of the achievements and challenges encountered in the clinical application of these materials,and proposes practical strategies to address current limitations and guide future research perspectives.展开更多
Silica fibers were modified by a specific ratio of SiB6 mixed with silica sol through vacuum impregnation method.The modified fibers were then incorporated into a phenolic resin matrix to prepare fiber-reinforced resi...Silica fibers were modified by a specific ratio of SiB6 mixed with silica sol through vacuum impregnation method.The modified fibers were then incorporated into a phenolic resin matrix to prepare fiber-reinforced resin composites.The influences of the SiB_(6)/SiO_(2)mixed modification on silica fiber properties were analyzed through thermogravimetric analysis(TGA),differential scanning calorimetry(DSC),scanning electron microscopy(SEM),and X-ray diffraction(XRD),respectively.Additionally,the influence of the SiB_(6)/SiO_(2)mixed modification on the mechanical properties of phenolic resin matrix composites was evaluated through mechanical testing.The experimeatal results indicate that the SiB_(6)/SiO_(2)mixed surface modification shows significant improvement in strength at room temperature and high temperatures,and crystallization temperature of silica fiber increases.The SiB_(6)/Silica sol co-modified silica fiber shows potential for future application in thermal protection and other high-temperature conditions.展开更多
Single crystalline nickel rich Li[Ni_(x)Co_(y)Mn_(1-x–y)]O_(2)(SCNCM)layered oxide cathodes show higher ionic conductivity and better structure integrity than polycrystalline NCM(PCNCM)cathodes by eliminating grain b...Single crystalline nickel rich Li[Ni_(x)Co_(y)Mn_(1-x–y)]O_(2)(SCNCM)layered oxide cathodes show higher ionic conductivity and better structure integrity than polycrystalline NCM(PCNCM)cathodes by eliminating grain boundaries.However,it remains challenges in the controlled synthesis process and restricted cycling stability of SCNCM.Herein,take single crystalline nickel rich Li[Ni_(0.8)Co_(0.1)Mn_(0.1)]O_(2)(SC811)as an example,a dual molten salts(LiOH and Li_(2)SO_(4))assisted secondary calcination method is proposed,for which LiOH salt improves primary crystal size and Li_(2)SO_(4)prevents the aggravation of NCM nanocrystals.To further reduce the interfacial side reactions,Mg-doping and B-coating surface modification was carried out,which effectively suppress anisotropic lattice changes and Li/Ni disorder.In addition,a thin and uniform H_(3)BO_(3)coating effectively prevents direct contact between the electrode and electrolyte,thus reducing harmful parasitic reactions.The single crystal structure engineering and surface modification strategy of oxide layered cathodes significantly improve the cycling stability of the modified SC811 cathode.For example,during a long-term cycling of 470 cycles,a high-capacity retention of 74.2%obtained at 1C rate.Our work provides a new strategy for engineering high energy nickel rich layered oxide NCM cathodes.展开更多
Four types of submicron Ag-coated Cu particles with different Ag contents were prepared as sintering paste fillers,and the Ag contents of the particles were measured to be 10,20,30,and 40 wt.%.Four types of particles(...Four types of submicron Ag-coated Cu particles with different Ag contents were prepared as sintering paste fillers,and the Ag contents of the particles were measured to be 10,20,30,and 40 wt.%.Four types of particles(in order of increasing Ag content:A10,A20,A30,and A40)were surface-modified with stearic acid,to suppress the Ag shell dewetting and improve sinterability.The surface-modified particles were mixed with a polyol-based solvent to fabricate a resin-free paste.Subsequently,the pastes were screen-printed onto a slide glass and sintered at 250°C in a nitrogen atmosphere for 1-10 min to form an electrode.The electrical resistivity of the sintered film as a function of sintering time was measured using a four-point probe.All the four surface-modified Cu@Ag particles with different Ag contents exhibited decreased electrical resistivity.Particularly,the largest difference in values after and before the surface modification was observed for A40 with the highest Ag content;the electrical resistivities of the initial and surface-modified particles were 1.51×10^(-4) and 6.67×10^(-5)Ω·cm,respectively,after sintering for 10 min.The findings of this study confirmed that the surface modification using stearic acid effectively suppressed the dewetting of the Ag shell and improved the sinterability of the submicron Cu@Ag particles.展开更多
In this paper,the stability of the results of ultrasonic wood surface modification after long-term storage,including macroscopic properties and microstructure of specimens,was investigated.Specimens of aspen wood(Popu...In this paper,the stability of the results of ultrasonic wood surface modification after long-term storage,including macroscopic properties and microstructure of specimens,was investigated.Specimens of aspen wood(Populus tremula)were processed by the developed ultrasonic method of wood surface modification in three different treatment modes and the surface hardness of the specimens was evaluated after processing and after storing the specimens for more than 5 years since long-term stability is an important factor for the use of ultrasonically modified sawn timber as construction and finishing materials.The obtained results of surface hardness measurements by the Leeb method showed that the decrease in hardness after long-term storage is approximately 6.6%for the lowest degree of treatment and approximately 3.4%and 2.4%for medium and high degrees of treatment,taking into account the fact of the average increase in surface hardness approximately 2–4 times,this decrease is insignificant.The internal structure of the specimens after storage was studied by scanning electron microscope(SEM),and deformations of the wood surface layer without damage or rupture were analyzed.The derived stable results confirm the potential of the ultrasonic method for wood surface modification.展开更多
Surface modification of fabrics is an effective way to endow them with antifouling properties while still maintaining their key advantages such as comfort,softness and stretchability.Herein,an atmospheric pressure die...Surface modification of fabrics is an effective way to endow them with antifouling properties while still maintaining their key advantages such as comfort,softness and stretchability.Herein,an atmospheric pressure dielectric barrier discharge(DBD)plasma method is demonstrated for the processing of silk fabrics using 1H,1H,2H,2H-perfluorodecyltriethoxysilane(PFDS)as the precursor.The results showed the successful grafting of PFDS groups onto the surface of silk fabrics without causing damage.Meanwhile,the gas temperature is rather low during the whole processing procedure,suggesting the non-equilibrium characteristics of DBD plasma.The influence on fabrics of the processing parameters(PFDS concentration,plasma treatment time and plasma discharge power)was systematically investigated.An optimum processing condition was determined to be a PFDS concentration of 8wt%,a plasma processing time of 40 s and a plasma power of 11.87 W.However,with prolonged plasma processing time or enhanced plasma power,the plasma-grafted PFDS films could be degraded.Further study revealed that plasma processing of silk fabrics with PFDS would lead to a change in their chemical composition and surface roughness.As a result,the surface energy of the fabrics was reduced,accompanied by improved water and oil repellency as well as enhanced antifouling performance.Besides,the plasma-grafted PFDS films also had good durability and stability.By extending the method to polyester and wool against different oil-/water-based stains,the DBD plasma surface modification technique demonstrated good versatility in improving the antifouling properties of fabrics.This work provides guidance for the surface modification of fabrics using DBD plasma to confer them with desirable functionalities.展开更多
Expanding the specific surface area of substrates and carrying out precise surface engineering of imprinted nanocavities are crucial methods for enhancing the identification efficiency of molecularly imprinted polymer...Expanding the specific surface area of substrates and carrying out precise surface engineering of imprinted nanocavities are crucial methods for enhancing the identification efficiency of molecularly imprinted polymers(MIPs).To implement this synergistic strategy,bioinspired surface engineering was used to incorporate dual covalent receptors via precise post-imprinting modifications(PIMs)onto mesoporous silica nanosheets.The prepared sorbents(denoted as‘‘D-PMIPs”)were utilized to improve the specific identification of adenosine 5-monophosphate(AMP).Significantly,the mesoporous silica nanosheets possess a high surface area of approximately 498.73 m^(2)·g^(-1),which facilitates the formation of abundant specific recognition sites in the D-PMIPs.The dual covalent receptors are valuable for estab-lishing the spatial orientation and arrangement of AMP through multiple cooperative interactions.PIMs enable precise site-specific functionalization within the imprinted cavities,leading to the tailor-made formation of complementary binding sites.The maximum number of high-affinity binding sites(Nmax)of the D-PMIPs is 39.99 lmol·g^(-1),which is significantly higher than that of imprinted sorbents with a sin-gle receptor(i.e.,S-BMIPs or S-PMIPs).The kinetic data of the D-PMIPs can be effectively described by a pseudo-second-order model,indicating that the main binding mechanism involves synergistic chemisorption from boronate affinity and the pyrimidine base.This study suggests that using dual cova-lent receptors and PIMs is a reliable approach for creating imprinted sorbents with high selectivity,allow-ing for the controlled engineering of imprinted sites.展开更多
The poor surface antibacterial properties are one of the important factors limiting the application of Carbon Fibers Reinforced Polyetheretherketone (CFR-P) composites as artificial bone replace materials. Some of the...The poor surface antibacterial properties are one of the important factors limiting the application of Carbon Fibers Reinforced Polyetheretherketone (CFR-P) composites as artificial bone replace materials. Some of the Two-Dimensional (2D) nanomaterials with unique lamellar structures and biological properties have been demonstrated to have excellent antibacterial properties. Antibacterial properties can be improved by feasible chemical strategies for preparing 2D nanomaterials coating on the surface of CFR-P. In this work, Black Phosphorus (BP) coating was prepared on the originally chemically inert CFR-P surface based on wet chemical pretreatment. The physical and chemical properties, including surface microstructure, chemical composition and state, roughness and hydrophilicity were characterized. The antibacterial ratios against Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), and Streptococcus mutans (S. mutans) were evaluated. The results indicated that hydrophilicity of BP coating on CFR-P was significantly higher compared to that of the pure CFR-P. Wet chemical pretreatment using mixed acid reagents (concentrated sulfuric acid and concentrated nitric acid) introduced hydroxyl, carboxyl and nitro groups on CFR-P. The BP coating exhibited the antibacterial rate of over 98% against both S. aureus and E. coli. In addition, the antibacterial rate of BP coating against the main pathogenic bacteria of dental caries, Streptococcus mutans, reached 45%.展开更多
Biodegradable implants from magnesium(Mg)alloys have emerged in the biomedical field especially in the orthopedic and cardiovascular stent applications owing to their low density,high specific strength,excellent machi...Biodegradable implants from magnesium(Mg)alloys have emerged in the biomedical field especially in the orthopedic and cardiovascular stent applications owing to their low density,high specific strength,excellent machinability,good biocompatibility,and biodegradability.The primary shortcoming of Mg-based implants is their low corrosion resistance in the physiological environment,which results in premature mechanical integrity loss before adequate healing and the production of excessive hydrogen gas,which is harmful to the body tissues and negatively affects the biocompatibility of the implant.Laser surface modification has recently received attention because it can improve the surface properties such as surface chemistry,roughness,topography,corrosion resistance,wear resistance,hydrophilicity,and thus cell response to the surface of the material.The composition and microstructures including textures and phases of laser-treated surfaces depend largely on the laser processing parameters(input laser power,laser scan velocity,frequency,pulse duration,pressure,gas circulation,working time,spot size,beam focal position,and laser track overlap)and the thermophysical properties of the substrate(solubility,melting point,and boiling point).This review investigates the impacts of various laser surface modification techniques including laser surface melting,laser surface alloying,laser cladding,laser surface texturing,and laser shock peening,and highlights their significance in improving the surface properties of biodegradable Mg alloys for implant applications.Additionally,we explore how different laser process parameters affect its composition,microstructure,and surface properties in each laser surface modification technique.展开更多
Full concentration gradient lithium-rich layered oxides are catching lots of interest as the next generation cathode for lithium-ion batteries due to their high discharge voltage,reduced voltage decay and enhanced rat...Full concentration gradient lithium-rich layered oxides are catching lots of interest as the next generation cathode for lithium-ion batteries due to their high discharge voltage,reduced voltage decay and enhanced rate performance,whereas the high lithium residues on its surface impairs the structure stability and long-term cycle performance.Herein,a facile multifunctional surface modification method is implemented to eliminate surface lithium residues of full concentration gradient lithium-rich layered oxides by a wet chemistry reaction with tetrabutyl titanate and the post-annealing process.It realizes not only a stable Li_(2)TiO_(3)coating layer with 3D diffusion channels for fast Li^(+)ions transfer,but also dopes partial Ti^(4+)ions into the sub-surface region of full concentration gradient lithium-rich layered oxides to further strengthen its crystal structure.Consequently,the modified full concentration gradient lithium-rich layered oxides exhibit improved structure stability,elevated thermal stability with decomposition temperature from 289.57℃to 321.72℃,and enhanced cycle performance(205.1 mAh g^(-1)after 150 cycles)with slowed voltage drop(1.67 mV per cycle).This work proposes a facile and integrated modification method to enhance the comprehensive performance of full concentration gradient lithium-rich layered oxides,which can facilitate its practical application for developing higher energy density lithium-ion batteries.展开更多
The ohmic contact interface between diamond and metal is essential for the application of diamond detectors.Surface modification can significantly affect the contact performance and eliminate the interface polarizatio...The ohmic contact interface between diamond and metal is essential for the application of diamond detectors.Surface modification can significantly affect the contact performance and eliminate the interface polarization effect.However,the radiation stability of a diamond detector is also sensitive to surface modification.In this work,the influence of surface modification technology on a diamond ohmic contact under high-energy radiation was investigated.Before radiation,the specific contact resistivities(ρc)between Ti/Pt/Au-hydrogen-terminated diamond(H-diamond)and Ti/Pt/Au-oxygenterminated diamond(O-diamond)were 2.0×10^(-4)W·cm^(2) and 4.3×10^(-3)Wcm^(2),respectively.After 10 MeV electron radiation,the ρc of Ti/Pt/Au H-diamond and Ti/Pt/Au O-diamond were 5.3×10^(-3)W·cm^(2)and 9.1×10^(-3)W·cm^(2),respectively.The rates of change of ρc of H-diamond and O-diamond after radiation were 2550%and 112%,respectively.The electron radiation promotes bond reconstruction of the diamond surface,resulting in an increase in ρc.展开更多
A bonding approach based on laser surface modification was developed to address the poor bonding be-tween Si_(3)N_(4) ceramic and Cu.The bonding mechanism in Si_(3)N_(4)/Cu heterogeneous composite structure fabricated...A bonding approach based on laser surface modification was developed to address the poor bonding be-tween Si_(3)N_(4) ceramic and Cu.The bonding mechanism in Si_(3)N_(4)/Cu heterogeneous composite structure fabricated by laser modification-assisted bonding is examined by means of scanning/transmission elec-tron microscopy and thermodynamic analysis.In the bonding process under laser modification,atomic intermixing at the interface is confirmed,as a result of the enhanced diffusion assisted by the dissocia-tion of Si_(3)N_(4) ceramic by laser.The dissociating Si precipitations on the surface,as well as the formation of micro-pores interfacial structure,would be the key concept of the bonding,by which the seamless and robust heterointerfaces were created.By controlling the laser-modifying conditions,we can obtain a reli-able heterostructure via the optimization of the trade-off of the surface structure and bonding strength,as determined by the laser-modified surface prior to bonding.The maximum structure depth and S ratio at the Si_(3)N_(4) surface were produced at a laser power of 56 W,corresponding to the maximal shear strength of 15.26 MPa.It is believed that the further development of this bonding technology will advance power electronic substrate fabrication applied in high-power devices.展开更多
Investigating zeolites as hydrogen storage scaffolds is imperative due to their porous nature and favorable physicochemical properties.Nevertheless,the storage capacity of the unmodified zeolites has been rather unsat...Investigating zeolites as hydrogen storage scaffolds is imperative due to their porous nature and favorable physicochemical properties.Nevertheless,the storage capacity of the unmodified zeolites has been rather unsatisfactory(0.224%-1.082%(mass))compared to its modified counterpart.Thus,the contemporary focus on enhancing hydrogen storage capacities has led to significant attention towards the utilization of modified zeolites,with studies exploring surface modifications through physical and chemical treatments,as well as the integration of various active metals.The enhanced hydrogen storage properties of zeolites are attributed to the presence of aluminosilicates from alkaline and alkaline-earth metals,resulting in increased storage capacity through interactions with the charge density of these aluminosilicates.Therefore,there is a great demand to critically review their role such as well-defined topology,pore structure,good thermal stability,and tunable hydrophilicity in enhanced hydrogen storage.This article aimed to critically review the recent research findings based on modified zeolite performance for enhanced hydrogen storage.Some of the factors affecting the hydrogen storage capacities of zeolites that can affect the rate of reaction and the stability of the adsorbent,like pressure,structure,and morphology were studied,and examined.Then,future perspectives,recommendations,and directions for modified zeolites were discussed.展开更多
Since the magnesium and magnesium alloys have good load transmission,exceptional biosafety,unique biodegradability,etc,they have significant application possibilities in the field of medical implantation.Furthermore,e...Since the magnesium and magnesium alloys have good load transmission,exceptional biosafety,unique biodegradability,etc,they have significant application possibilities in the field of medical implantation.Furthermore,excellent corrosion resistance is one of the paramount prerequisites for magnesium and magnesium alloys as medical implants.However,magnesium alloys exhibit poor corrosion resistance,leading to rapid degradation in physiological environments due to high corrosion rates.This premature degradation,before completing their intended service life,compromises their structural integrity,severely limiting their clinical applications.Surface modification treatment of magnesium alloy to improve corrosion resistance has become a research hotspot of medical magnesium alloy.This study primarily focused on the research advancements in the corrosion resistance enhancement of medical magnesium alloys.The developmental trajectory and characteristics of medical magnesium alloys were outlined.Additionally,surface modification techniques such as micro-arc oxidation and ion implantation,as well as microstructure and properties of magnesium alloy surfaces after surface modification were reviewed.The formation mechanisms of various coatings were discussed,and their structures and properties were analyzed.The impact of coatings on the degradation rate of magnesium alloys was elucidated,aiming to identify key issues and potential solutions in the implementation and application of surface modification for medical magnesium alloys.Recommendations were also provided,presenting the research directions for surface modification of medical magnesium alloys.展开更多
The rapid development of iron and steel metallurgy technology has promoted the continuous innovation and iteration of carbon-containing refractories for clean steel smelting.To meet the high-quality requirements for c...The rapid development of iron and steel metallurgy technology has promoted the continuous innovation and iteration of carbon-containing refractories for clean steel smelting.To meet the high-quality requirements for clean steel production and full exploit the performance advantages of carbon-containing refractories in dynamic smelting environment,it is necessary to explore the role of graphite and modified graphite in carbon-containing refractories.Based on this,graphite surface modification methods,including surfactants,surface oxidation,and surface coating,and their applications in carbon-containing refractories are reviewed.The advantages and disadvantages of each method are analyzed for practical use.Furthermore,combined with the existing problems,the application prospect of improved graphite in carbon-containing refractories is discussed.展开更多
Solving intrinsic structural problems such as low conductivity is the main challenge to promote the commercial application of Li_(2)TiSiO_(5).In this study,Li_(2)TiSiO_(5) is synthesized by the sol-gelmethod,and the s...Solving intrinsic structural problems such as low conductivity is the main challenge to promote the commercial application of Li_(2)TiSiO_(5).In this study,Li_(2)TiSiO_(5) is synthesized by the sol-gelmethod,and the surface modification of Li_(2)TiSiO_(5) is carried out at different temperatures using low-temperature plasma to enhance its lithium storage performance.The morphological structure and electrochemical tests demonstrate that plasma treatment can improve the degree of agglomeration.The peak position of the plasma-treated Li_(2)TiSiO_(5) is shifted to a lower angle,and the shift angle increases with increasing sputtering power.Li_(2)TiSiO_(5) after 300 W bombardment shows excellent capacity(144.7 mA·hg^(−1)after 500 cycles at 0.1 Ag^(−1))and rate performance(140 mA·hg^(−1)at 5 Ag^(−1)).Electrochemical analysis indicates that excellent electrochemical performance is attributed to the enhancement of electronic and ionic conductivity by plasma bombardment.展开更多
Polyetheretherketone(PEEK)has been recognized for its immense potential in hard tissue repair applications due to its mechanical properties resembling those of natural bones.However,the inherent bioinertness of pristi...Polyetheretherketone(PEEK)has been recognized for its immense potential in hard tissue repair applications due to its mechanical properties resembling those of natural bones.However,the inherent bioinertness of pristine PEEK results in insufficient osseointegration.Moreover,implant-associated infection(IAI)has become a serious threat in orthopedic surgery.These risks usually lead to implant loosening,delayed healing,and even the failure of implantation,hampering many clinical applications of PEEK.In this study,we present a facile strategy to endow PEEK implants with enhanced osseointegration and pH-responsive antibacterial activity.Briefly,pristine PEEK was first treated with mixed acids to obtain a porous structure(referred to as SNPEEK),and then the metal-phenolic networks(MPN)coating was prepared using layer-by-layer(LbL)assembly consisting of Sr^(2+) and tannin acid(TA)(referred to as ST coating).The results demonstrated that the dual-functional PEEK displayed enhanced antibacterial activity in pH-responsive manner.At pH 7.4,the antibacterial ratios were 71.72%and 66.79%against Staphylococcus aureus(MSSA,ATCC 25,923)and methicillin-resistant Staphylococcus aureus(MRSA,ATCC BAA-40),respectively.Remarkably,at pH 5.5,the antibacterial activities significantly increased,resulting in killing ratios of 99.98%and 100%,respectively.Furthermore,the dual-functional PEEK promoted osteogenic differentiation of pre-osteoblasts(MC3T3-E1)and migration of human umbilical vascular endothelial cells(HUVECs).In addition,the dual-functional PEEK demonstrated effective anti-infection ability and desirable new bone formation ability in vivo compared to both pristine PEEK and SNPEEK implants.Overall,this study provides a promising strategy to endow PEEK implants with effective osseointegration and anti-infective ability,representing a prospective solution to address current clinical challenges associated with PEEK implants.展开更多
A Cu-25Cr alloy prepared by vacuum induction melting method was treated by the high current pulsed electron beam （HCPEB） with pulse numbers ranging from 1 to 100. Surface morphologies and microstructures of the allo...A Cu-25Cr alloy prepared by vacuum induction melting method was treated by the high current pulsed electron beam （HCPEB） with pulse numbers ranging from 1 to 100. Surface morphologies and microstructures of the alloy before and after the treatment were investigated by scanning electron microscopy and X-ray diffraction. The results show that significant surface modification can be induced by HCPEB with the pulse number reaching 10. Craters with typical morphologies on the Cu-25Cr alloy surface are formed due to the dynamic thermal field induced by the HCPEB. Micro-cracks, as a unique feature, are well revealed in the irradiated Cu-25Cr specimens and attributed to quasi-static thermal stresses accumulated along the specimen surface. The amount of cracks is found to increase with the pulse number and a preference of these cracks to Cr phases rather than Cu phases is also noted. Another characteristic produced by the HCPEB is the fine Cr spheroids, which are determined to be due to occurrence of liquid phase separation in the Cu-25Cr alloy. In addition, an examination on surface roughness of all specimens reveals that more pulses will produce a roughened surface, as a result of compromising the above features.展开更多
基金National Natural Science Foundation of China(52171114)。
文摘Infections associated with titanium(Ti)-based implants present significant challenges in clinical treatments,especially when biofilms already form on the implant surface.Many antimicrobial agents,including antibiotics,metallic nanoparticles and antimicrobial peptides,have been extensively used to deal with Ti implant infections.However,these chemical approaches suffer from potential toxicity,antibiotic resistance and poor long-term antibacterial performance.Hence,physical antibacterial surfaces on Ti-based implants have attracted increasing attention.The antibacterial behavior of different surfaces on Ti-based biomaterials against various bacteria only by physical properties of the implants themselves(e.g.,nanotopography)or exogenous physical stimulus(e.g.,photocatalysis)was reviewed,as well as parameters influencing the physical antibacterial processes,such as size,shape and density of the surface nanotextures,and bacterial growth phases.Besides,mechanisms of different fabrication techniques for the physical antibacterial surfaces on Ti-based biomaterials were also summarized.
基金supported by National Natural Science Foundation of China(Grant No.52275343)Natural Science Foundation of Zhejiang Province(Grant No.LY23E050003)Ningbo Youth Science and Technology Innovation Leading Talent Project(Grant No.2023QL021).
文摘Additive manufacturing(AM)has revolutionized the production of metal bone implants,enabling unprecedented levels of customization and functionality.Recent advancements in surface-modification technologies have been crucial in enhancing the performance and biocompatibility of implants.Through leveraging the versatility of AM techniques,particularly powder bed fusion,a range of metallic biomaterials,including stainless steel,titanium,and biodegradable alloys,can be utilized to fabricate implants tailored for craniofacial,trunk,and limb bone reconstructions.However,the potential of AM is contingent on addressing intrinsic defects that may hinder implant performance.Techniques such as sandblasting,chemical treatment,electropolishing,heat treatment,and laser technology effectively remove residual powder and improve the surface roughness of these implants.The development of functional coatings,applied via both dry and wet methods,represents a significant advancement in surface modification research.These coatings not only improve mechanical and biological interactions at the implant-bone interface but also facilitate controlled drug release and enhance antimicrobial properties.Addition-ally,micro-and nanoscale surface modifications using chemical and laser techniques can precisely sculpt implant surfaces to promote the desired cellular responses.This detailed exploration of surface engineering offers a wealth of opportunities for creating next-generation implants that are not only biocompatible but also bioactive,laying the foundation for more effective solutions in bone reconstruction.
基金supported by the Science and Technology Planning Project of Guangdong Province(Nos.2024A0505040016 and 2023A0505050148)National Key Research and Development Project of China(2023YFB3809900/2023YFB3809902)Natural Science Foundation of Guangdong Province(No.2025A1515010026)。
文摘Biodegradable metals have garnered considerable interest owing to their capacity for self-degradation following the repair of damaged tissues.This review commences with their historical development and clarifies the essential prerequisites for their successful clinical translation.Subsequently,a detailed review of magnesium-based materials is presented from five critical areas of alloying,fabrication techniques,purification,surface modification,and structural design,systematically addressing their progress in biodegradation rate retardation,mechanical reinforcement,and biocompatibility enhancement.Furthermore,recent breakthroughs in vivo animal experiments and clinical translation of magnesium alloys are summarized.Finally,this review concludes with a critical assessment of the achievements and challenges encountered in the clinical application of these materials,and proposes practical strategies to address current limitations and guide future research perspectives.
基金Funded by the Natural Science Foundation of Hubei Province(No.2024AFB833)。
文摘Silica fibers were modified by a specific ratio of SiB6 mixed with silica sol through vacuum impregnation method.The modified fibers were then incorporated into a phenolic resin matrix to prepare fiber-reinforced resin composites.The influences of the SiB_(6)/SiO_(2)mixed modification on silica fiber properties were analyzed through thermogravimetric analysis(TGA),differential scanning calorimetry(DSC),scanning electron microscopy(SEM),and X-ray diffraction(XRD),respectively.Additionally,the influence of the SiB_(6)/SiO_(2)mixed modification on the mechanical properties of phenolic resin matrix composites was evaluated through mechanical testing.The experimeatal results indicate that the SiB_(6)/SiO_(2)mixed surface modification shows significant improvement in strength at room temperature and high temperatures,and crystallization temperature of silica fiber increases.The SiB_(6)/Silica sol co-modified silica fiber shows potential for future application in thermal protection and other high-temperature conditions.
基金financially supported by the National Natural Science Foundation of China under the Grant No.22209075。
文摘Single crystalline nickel rich Li[Ni_(x)Co_(y)Mn_(1-x–y)]O_(2)(SCNCM)layered oxide cathodes show higher ionic conductivity and better structure integrity than polycrystalline NCM(PCNCM)cathodes by eliminating grain boundaries.However,it remains challenges in the controlled synthesis process and restricted cycling stability of SCNCM.Herein,take single crystalline nickel rich Li[Ni_(0.8)Co_(0.1)Mn_(0.1)]O_(2)(SC811)as an example,a dual molten salts(LiOH and Li_(2)SO_(4))assisted secondary calcination method is proposed,for which LiOH salt improves primary crystal size and Li_(2)SO_(4)prevents the aggravation of NCM nanocrystals.To further reduce the interfacial side reactions,Mg-doping and B-coating surface modification was carried out,which effectively suppress anisotropic lattice changes and Li/Ni disorder.In addition,a thin and uniform H_(3)BO_(3)coating effectively prevents direct contact between the electrode and electrolyte,thus reducing harmful parasitic reactions.The single crystal structure engineering and surface modification strategy of oxide layered cathodes significantly improve the cycling stability of the modified SC811 cathode.For example,during a long-term cycling of 470 cycles,a high-capacity retention of 74.2%obtained at 1C rate.Our work provides a new strategy for engineering high energy nickel rich layered oxide NCM cathodes.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(No.2021R1A2C1007400)supported,partly,by the National R&D Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Science and ICT(Nos.NRF-2020M3H4A3106383,NRF2020M3H4A3081764)+1 种基金supported,partly,by ETRI(No.21YB1610)supported by a Korea Institute for Advancement of Technology(KIAT)grant funded by the Korea Government(MOTIE)(No.P0008458,HRD Program for Industrial Innovation)。
文摘Four types of submicron Ag-coated Cu particles with different Ag contents were prepared as sintering paste fillers,and the Ag contents of the particles were measured to be 10,20,30,and 40 wt.%.Four types of particles(in order of increasing Ag content:A10,A20,A30,and A40)were surface-modified with stearic acid,to suppress the Ag shell dewetting and improve sinterability.The surface-modified particles were mixed with a polyol-based solvent to fabricate a resin-free paste.Subsequently,the pastes were screen-printed onto a slide glass and sintered at 250°C in a nitrogen atmosphere for 1-10 min to form an electrode.The electrical resistivity of the sintered film as a function of sintering time was measured using a four-point probe.All the four surface-modified Cu@Ag particles with different Ag contents exhibited decreased electrical resistivity.Particularly,the largest difference in values after and before the surface modification was observed for A40 with the highest Ag content;the electrical resistivities of the initial and surface-modified particles were 1.51×10^(-4) and 6.67×10^(-5)Ω·cm,respectively,after sintering for 10 min.The findings of this study confirmed that the surface modification using stearic acid effectively suppressed the dewetting of the Ag shell and improved the sinterability of the submicron Cu@Ag particles.
文摘In this paper,the stability of the results of ultrasonic wood surface modification after long-term storage,including macroscopic properties and microstructure of specimens,was investigated.Specimens of aspen wood(Populus tremula)were processed by the developed ultrasonic method of wood surface modification in three different treatment modes and the surface hardness of the specimens was evaluated after processing and after storing the specimens for more than 5 years since long-term stability is an important factor for the use of ultrasonically modified sawn timber as construction and finishing materials.The obtained results of surface hardness measurements by the Leeb method showed that the decrease in hardness after long-term storage is approximately 6.6%for the lowest degree of treatment and approximately 3.4%and 2.4%for medium and high degrees of treatment,taking into account the fact of the average increase in surface hardness approximately 2–4 times,this decrease is insignificant.The internal structure of the specimens after storage was studied by scanning electron microscope(SEM),and deformations of the wood surface layer without damage or rupture were analyzed.The derived stable results confirm the potential of the ultrasonic method for wood surface modification.
基金the financial support from National Natural Science Foundation of China(Nos.22078125 and 52004102)Postdoctoral Science Foundation of China(No.2023M741472)。
文摘Surface modification of fabrics is an effective way to endow them with antifouling properties while still maintaining their key advantages such as comfort,softness and stretchability.Herein,an atmospheric pressure dielectric barrier discharge(DBD)plasma method is demonstrated for the processing of silk fabrics using 1H,1H,2H,2H-perfluorodecyltriethoxysilane(PFDS)as the precursor.The results showed the successful grafting of PFDS groups onto the surface of silk fabrics without causing damage.Meanwhile,the gas temperature is rather low during the whole processing procedure,suggesting the non-equilibrium characteristics of DBD plasma.The influence on fabrics of the processing parameters(PFDS concentration,plasma treatment time and plasma discharge power)was systematically investigated.An optimum processing condition was determined to be a PFDS concentration of 8wt%,a plasma processing time of 40 s and a plasma power of 11.87 W.However,with prolonged plasma processing time or enhanced plasma power,the plasma-grafted PFDS films could be degraded.Further study revealed that plasma processing of silk fabrics with PFDS would lead to a change in their chemical composition and surface roughness.As a result,the surface energy of the fabrics was reduced,accompanied by improved water and oil repellency as well as enhanced antifouling performance.Besides,the plasma-grafted PFDS films also had good durability and stability.By extending the method to polyester and wool against different oil-/water-based stains,the DBD plasma surface modification technique demonstrated good versatility in improving the antifouling properties of fabrics.This work provides guidance for the surface modification of fabrics using DBD plasma to confer them with desirable functionalities.
基金supported by the National Natural Science Foundation of China(22078132,22108103,and U22A20413)the Open Funding Project of the National Key Labora-tory of Biochemical Engineering(2021KF-02)+3 种基金China Postdoctoral Science Foundation(2021M691301)Jiangsu Key Research and Development Program(BE2022356)the Postdoctoral Fellowship Program of China Postdoctoral Science Foundation(CPSF)(GZ20230989)Jiangsu Agricultural Independent Innovation Fund Project(CX(21)3079).
文摘Expanding the specific surface area of substrates and carrying out precise surface engineering of imprinted nanocavities are crucial methods for enhancing the identification efficiency of molecularly imprinted polymers(MIPs).To implement this synergistic strategy,bioinspired surface engineering was used to incorporate dual covalent receptors via precise post-imprinting modifications(PIMs)onto mesoporous silica nanosheets.The prepared sorbents(denoted as‘‘D-PMIPs”)were utilized to improve the specific identification of adenosine 5-monophosphate(AMP).Significantly,the mesoporous silica nanosheets possess a high surface area of approximately 498.73 m^(2)·g^(-1),which facilitates the formation of abundant specific recognition sites in the D-PMIPs.The dual covalent receptors are valuable for estab-lishing the spatial orientation and arrangement of AMP through multiple cooperative interactions.PIMs enable precise site-specific functionalization within the imprinted cavities,leading to the tailor-made formation of complementary binding sites.The maximum number of high-affinity binding sites(Nmax)of the D-PMIPs is 39.99 lmol·g^(-1),which is significantly higher than that of imprinted sorbents with a sin-gle receptor(i.e.,S-BMIPs or S-PMIPs).The kinetic data of the D-PMIPs can be effectively described by a pseudo-second-order model,indicating that the main binding mechanism involves synergistic chemisorption from boronate affinity and the pyrimidine base.This study suggests that using dual cova-lent receptors and PIMs is a reliable approach for creating imprinted sorbents with high selectivity,allow-ing for the controlled engineering of imprinted sites.
基金support of the National Natural Science Foundation of China(61971301)In part by the Central Guidance on Local Science and Technology Development Fund of Shanxi Province under Grant YDZJSX2021A018+1 种基金Shanxi Province Higher Education Science and Technology Innovation Plan Project(2022L060)the Fundamental Research Program of Shanxi Province(Nos.202203021212227,202303021212082).
文摘The poor surface antibacterial properties are one of the important factors limiting the application of Carbon Fibers Reinforced Polyetheretherketone (CFR-P) composites as artificial bone replace materials. Some of the Two-Dimensional (2D) nanomaterials with unique lamellar structures and biological properties have been demonstrated to have excellent antibacterial properties. Antibacterial properties can be improved by feasible chemical strategies for preparing 2D nanomaterials coating on the surface of CFR-P. In this work, Black Phosphorus (BP) coating was prepared on the originally chemically inert CFR-P surface based on wet chemical pretreatment. The physical and chemical properties, including surface microstructure, chemical composition and state, roughness and hydrophilicity were characterized. The antibacterial ratios against Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), and Streptococcus mutans (S. mutans) were evaluated. The results indicated that hydrophilicity of BP coating on CFR-P was significantly higher compared to that of the pure CFR-P. Wet chemical pretreatment using mixed acid reagents (concentrated sulfuric acid and concentrated nitric acid) introduced hydroxyl, carboxyl and nitro groups on CFR-P. The BP coating exhibited the antibacterial rate of over 98% against both S. aureus and E. coli. In addition, the antibacterial rate of BP coating against the main pathogenic bacteria of dental caries, Streptococcus mutans, reached 45%.
基金the Australian Research Council(ARC)through the discovery grant DP210101862。
文摘Biodegradable implants from magnesium(Mg)alloys have emerged in the biomedical field especially in the orthopedic and cardiovascular stent applications owing to their low density,high specific strength,excellent machinability,good biocompatibility,and biodegradability.The primary shortcoming of Mg-based implants is their low corrosion resistance in the physiological environment,which results in premature mechanical integrity loss before adequate healing and the production of excessive hydrogen gas,which is harmful to the body tissues and negatively affects the biocompatibility of the implant.Laser surface modification has recently received attention because it can improve the surface properties such as surface chemistry,roughness,topography,corrosion resistance,wear resistance,hydrophilicity,and thus cell response to the surface of the material.The composition and microstructures including textures and phases of laser-treated surfaces depend largely on the laser processing parameters(input laser power,laser scan velocity,frequency,pulse duration,pressure,gas circulation,working time,spot size,beam focal position,and laser track overlap)and the thermophysical properties of the substrate(solubility,melting point,and boiling point).This review investigates the impacts of various laser surface modification techniques including laser surface melting,laser surface alloying,laser cladding,laser surface texturing,and laser shock peening,and highlights their significance in improving the surface properties of biodegradable Mg alloys for implant applications.Additionally,we explore how different laser process parameters affect its composition,microstructure,and surface properties in each laser surface modification technique.
基金financially supported by the Natural Science Foundation of Shandong Province(ZR2022QB166,ZR2020KE032)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA22010600)+3 种基金the Youth Innovation Promotion Association of CAS(2021210)the Foundation of Qingdao Postdoctoral Application Program(Y63302190F)the Natural Science Foundation of Qingdao Institute ofBioenergy and Bioprocess Technology(QIBEBT SZ202101)support from the Max Planck-POSTECH-Hsinchu Center for Complex Phase Materials
文摘Full concentration gradient lithium-rich layered oxides are catching lots of interest as the next generation cathode for lithium-ion batteries due to their high discharge voltage,reduced voltage decay and enhanced rate performance,whereas the high lithium residues on its surface impairs the structure stability and long-term cycle performance.Herein,a facile multifunctional surface modification method is implemented to eliminate surface lithium residues of full concentration gradient lithium-rich layered oxides by a wet chemistry reaction with tetrabutyl titanate and the post-annealing process.It realizes not only a stable Li_(2)TiO_(3)coating layer with 3D diffusion channels for fast Li^(+)ions transfer,but also dopes partial Ti^(4+)ions into the sub-surface region of full concentration gradient lithium-rich layered oxides to further strengthen its crystal structure.Consequently,the modified full concentration gradient lithium-rich layered oxides exhibit improved structure stability,elevated thermal stability with decomposition temperature from 289.57℃to 321.72℃,and enhanced cycle performance(205.1 mAh g^(-1)after 150 cycles)with slowed voltage drop(1.67 mV per cycle).This work proposes a facile and integrated modification method to enhance the comprehensive performance of full concentration gradient lithium-rich layered oxides,which can facilitate its practical application for developing higher energy density lithium-ion batteries.
基金Project supported by the National Key Research and Development Program of China(Grant No.2022YFB3608601).
文摘The ohmic contact interface between diamond and metal is essential for the application of diamond detectors.Surface modification can significantly affect the contact performance and eliminate the interface polarization effect.However,the radiation stability of a diamond detector is also sensitive to surface modification.In this work,the influence of surface modification technology on a diamond ohmic contact under high-energy radiation was investigated.Before radiation,the specific contact resistivities(ρc)between Ti/Pt/Au-hydrogen-terminated diamond(H-diamond)and Ti/Pt/Au-oxygenterminated diamond(O-diamond)were 2.0×10^(-4)W·cm^(2) and 4.3×10^(-3)Wcm^(2),respectively.After 10 MeV electron radiation,the ρc of Ti/Pt/Au H-diamond and Ti/Pt/Au O-diamond were 5.3×10^(-3)W·cm^(2)and 9.1×10^(-3)W·cm^(2),respectively.The rates of change of ρc of H-diamond and O-diamond after radiation were 2550%and 112%,respectively.The electron radiation promotes bond reconstruction of the diamond surface,resulting in an increase in ρc.
基金supported by the National Natural Science Foun-dation of China(grant Nos.52275318 and 52175307)Taishan Scholars Foundation of Shandong Province(No.tsqn201812128)+1 种基金Shandong Natural Science Foundation(Nos.ZR2023JQ021 and ZR2023QE221)China Academy of Space Technology Innovation Foundation(No.CAST2022).
文摘A bonding approach based on laser surface modification was developed to address the poor bonding be-tween Si_(3)N_(4) ceramic and Cu.The bonding mechanism in Si_(3)N_(4)/Cu heterogeneous composite structure fabricated by laser modification-assisted bonding is examined by means of scanning/transmission elec-tron microscopy and thermodynamic analysis.In the bonding process under laser modification,atomic intermixing at the interface is confirmed,as a result of the enhanced diffusion assisted by the dissocia-tion of Si_(3)N_(4) ceramic by laser.The dissociating Si precipitations on the surface,as well as the formation of micro-pores interfacial structure,would be the key concept of the bonding,by which the seamless and robust heterointerfaces were created.By controlling the laser-modifying conditions,we can obtain a reli-able heterostructure via the optimization of the trade-off of the surface structure and bonding strength,as determined by the laser-modified surface prior to bonding.The maximum structure depth and S ratio at the Si_(3)N_(4) surface were produced at a laser power of 56 W,corresponding to the maximal shear strength of 15.26 MPa.It is believed that the further development of this bonding technology will advance power electronic substrate fabrication applied in high-power devices.
基金supported by the Ministry of Higher Education Malaysia through the Fundamental Research Grant Scheme(FRGS)No.FRGS/1/2021/TK0/UMP/02/37(University Ref.RDU210135).
文摘Investigating zeolites as hydrogen storage scaffolds is imperative due to their porous nature and favorable physicochemical properties.Nevertheless,the storage capacity of the unmodified zeolites has been rather unsatisfactory(0.224%-1.082%(mass))compared to its modified counterpart.Thus,the contemporary focus on enhancing hydrogen storage capacities has led to significant attention towards the utilization of modified zeolites,with studies exploring surface modifications through physical and chemical treatments,as well as the integration of various active metals.The enhanced hydrogen storage properties of zeolites are attributed to the presence of aluminosilicates from alkaline and alkaline-earth metals,resulting in increased storage capacity through interactions with the charge density of these aluminosilicates.Therefore,there is a great demand to critically review their role such as well-defined topology,pore structure,good thermal stability,and tunable hydrophilicity in enhanced hydrogen storage.This article aimed to critically review the recent research findings based on modified zeolite performance for enhanced hydrogen storage.Some of the factors affecting the hydrogen storage capacities of zeolites that can affect the rate of reaction and the stability of the adsorbent,like pressure,structure,and morphology were studied,and examined.Then,future perspectives,recommendations,and directions for modified zeolites were discussed.
基金Key R&D Plan Projects in Shaanxi Province(2020ZDLGY13-05,2022SF-294,2023-YBSF-354)Xi'an City Research Science and Technology Project(22GXFW0143)+1 种基金Weiyang District Research Science and Technology Project(202106)Northwest Institute for Nonferrous Metal Research Science and Technology Project(YK2113,YK2119)。
文摘Since the magnesium and magnesium alloys have good load transmission,exceptional biosafety,unique biodegradability,etc,they have significant application possibilities in the field of medical implantation.Furthermore,excellent corrosion resistance is one of the paramount prerequisites for magnesium and magnesium alloys as medical implants.However,magnesium alloys exhibit poor corrosion resistance,leading to rapid degradation in physiological environments due to high corrosion rates.This premature degradation,before completing their intended service life,compromises their structural integrity,severely limiting their clinical applications.Surface modification treatment of magnesium alloy to improve corrosion resistance has become a research hotspot of medical magnesium alloy.This study primarily focused on the research advancements in the corrosion resistance enhancement of medical magnesium alloys.The developmental trajectory and characteristics of medical magnesium alloys were outlined.Additionally,surface modification techniques such as micro-arc oxidation and ion implantation,as well as microstructure and properties of magnesium alloy surfaces after surface modification were reviewed.The formation mechanisms of various coatings were discussed,and their structures and properties were analyzed.The impact of coatings on the degradation rate of magnesium alloys was elucidated,aiming to identify key issues and potential solutions in the implementation and application of surface modification for medical magnesium alloys.Recommendations were also provided,presenting the research directions for surface modification of medical magnesium alloys.
基金the project supported by the Natural Science Foundation of Hubei Province(Grant No.2023BAB106)the National Natural Science Foundation of China(Grant No.U20A20239).
文摘The rapid development of iron and steel metallurgy technology has promoted the continuous innovation and iteration of carbon-containing refractories for clean steel smelting.To meet the high-quality requirements for clean steel production and full exploit the performance advantages of carbon-containing refractories in dynamic smelting environment,it is necessary to explore the role of graphite and modified graphite in carbon-containing refractories.Based on this,graphite surface modification methods,including surfactants,surface oxidation,and surface coating,and their applications in carbon-containing refractories are reviewed.The advantages and disadvantages of each method are analyzed for practical use.Furthermore,combined with the existing problems,the application prospect of improved graphite in carbon-containing refractories is discussed.
基金supported by Changzhou Basic Research Program(No.CJ20235030)the Research Initiation Fund of Changzhou University(No.ZMF23020057).
文摘Solving intrinsic structural problems such as low conductivity is the main challenge to promote the commercial application of Li_(2)TiSiO_(5).In this study,Li_(2)TiSiO_(5) is synthesized by the sol-gelmethod,and the surface modification of Li_(2)TiSiO_(5) is carried out at different temperatures using low-temperature plasma to enhance its lithium storage performance.The morphological structure and electrochemical tests demonstrate that plasma treatment can improve the degree of agglomeration.The peak position of the plasma-treated Li_(2)TiSiO_(5) is shifted to a lower angle,and the shift angle increases with increasing sputtering power.Li_(2)TiSiO_(5) after 300 W bombardment shows excellent capacity(144.7 mA·hg^(−1)after 500 cycles at 0.1 Ag^(−1))and rate performance(140 mA·hg^(−1)at 5 Ag^(−1)).Electrochemical analysis indicates that excellent electrochemical performance is attributed to the enhancement of electronic and ionic conductivity by plasma bombardment.
基金supported by the National Natu-ral Science Foundation of China(No.52073230)the Shaanxi Provincial Science Fund for Distinguished Young Scholars(No.2023-JC-JQ-32).
文摘Polyetheretherketone(PEEK)has been recognized for its immense potential in hard tissue repair applications due to its mechanical properties resembling those of natural bones.However,the inherent bioinertness of pristine PEEK results in insufficient osseointegration.Moreover,implant-associated infection(IAI)has become a serious threat in orthopedic surgery.These risks usually lead to implant loosening,delayed healing,and even the failure of implantation,hampering many clinical applications of PEEK.In this study,we present a facile strategy to endow PEEK implants with enhanced osseointegration and pH-responsive antibacterial activity.Briefly,pristine PEEK was first treated with mixed acids to obtain a porous structure(referred to as SNPEEK),and then the metal-phenolic networks(MPN)coating was prepared using layer-by-layer(LbL)assembly consisting of Sr^(2+) and tannin acid(TA)(referred to as ST coating).The results demonstrated that the dual-functional PEEK displayed enhanced antibacterial activity in pH-responsive manner.At pH 7.4,the antibacterial ratios were 71.72%and 66.79%against Staphylococcus aureus(MSSA,ATCC 25,923)and methicillin-resistant Staphylococcus aureus(MRSA,ATCC BAA-40),respectively.Remarkably,at pH 5.5,the antibacterial activities significantly increased,resulting in killing ratios of 99.98%and 100%,respectively.Furthermore,the dual-functional PEEK promoted osteogenic differentiation of pre-osteoblasts(MC3T3-E1)and migration of human umbilical vascular endothelial cells(HUVECs).In addition,the dual-functional PEEK demonstrated effective anti-infection ability and desirable new bone formation ability in vivo compared to both pristine PEEK and SNPEEK implants.Overall,this study provides a promising strategy to endow PEEK implants with effective osseointegration and anti-infective ability,representing a prospective solution to address current clinical challenges associated with PEEK implants.
基金Projects(51101177,51401040,51171146,51171216) supported by the National Natural Science Foundation of ChinaProject(CSTC2012JJA245) supported by the Natural Science Foundation of Chongqing,China
文摘A Cu-25Cr alloy prepared by vacuum induction melting method was treated by the high current pulsed electron beam （HCPEB） with pulse numbers ranging from 1 to 100. Surface morphologies and microstructures of the alloy before and after the treatment were investigated by scanning electron microscopy and X-ray diffraction. The results show that significant surface modification can be induced by HCPEB with the pulse number reaching 10. Craters with typical morphologies on the Cu-25Cr alloy surface are formed due to the dynamic thermal field induced by the HCPEB. Micro-cracks, as a unique feature, are well revealed in the irradiated Cu-25Cr specimens and attributed to quasi-static thermal stresses accumulated along the specimen surface. The amount of cracks is found to increase with the pulse number and a preference of these cracks to Cr phases rather than Cu phases is also noted. Another characteristic produced by the HCPEB is the fine Cr spheroids, which are determined to be due to occurrence of liquid phase separation in the Cu-25Cr alloy. In addition, an examination on surface roughness of all specimens reveals that more pulses will produce a roughened surface, as a result of compromising the above features.
