Nano-Ag particles/polyacrylamide （PAM） composites were synthesized by γ irradiation method and then blended with ethylene vinyl acetate （EVA）. Dielectric behaviors of the Ag/PAM/EVA composites are investigated as...Nano-Ag particles/polyacrylamide （PAM） composites were synthesized by γ irradiation method and then blended with ethylene vinyl acetate （EVA）. Dielectric behaviors of the Ag/PAM/EVA composites are investigated as a function of both the concentration and size of Ag particles. When concentration of the Ag fillers is rarely low, dielectric anomalies were first observed in contrast to the traditional percolation theory. As concentration of Ag increases, volume resistivity and breakdown field strength are enhanced, loss tangent （tan δ） reduced and dielectric constant kept invariable. In addition, the above variation became larger when the diameter of the Ag nano-particles is smaller. Such dielectric anomalies may be understood by considering the unique ＂Coulomb Blockade Effect＂ of the nano-sized Ag particles.展开更多
Nano-silver and waterborne polyurethane(WPU)composite emulsion was synthesized.The average diameter of silver nanoparticles(SNPs)was about 20 nm,and the average diameter of WPU was 101.32 nm.The anti-bacteria finishin...Nano-silver and waterborne polyurethane(WPU)composite emulsion was synthesized.The average diameter of silver nanoparticles(SNPs)was about 20 nm,and the average diameter of WPU was 101.32 nm.The anti-bacteria finishing of a polypropylene non-woven fabric(NWF)was carried out by ultraviolet finishing technology and the double dipping twin-roll method.The standard AATCC100 was used to test the antimicrobial activity of the samples.The results showed that the antimicrobial rates of Klebsiella pneumoniae(K.pneumoniae)and Staphylococcus aureus(S.aureus)were above 90%,which indicated that the NWF finishing had good antimicrobial activity.In addition,the thermal stability,mechanical properties,whiteness and contact angle of antimicrobial finishing nonwovens were characterized.The results showed that the performance of antimicrobial nonwovens was stable at 300℃.The breaking strength was better than that of untreated nonwovens,and the contact angle reached 119.1°.展开更多
A facile solution processed strategy of synthesizing nano silver assembled on carbon nanotubes （CNTs） at room temperature was put forward. Activated carbon nanotubes were used as precursors for preparing silver-deco...A facile solution processed strategy of synthesizing nano silver assembled on carbon nanotubes （CNTs） at room temperature was put forward. Activated carbon nanotubes were used as precursors for preparing silver-decorated nanotubes. The nature of the decorated nanotubes was studied using transmission electron microscopy （TEM）, scanning electron microscopy （SEM）, and energy-dispersive X-ray spectroscopy （EDX）. The inert surfaces of carbon nanotubes were activated by introducing catalytic nuclei via an oxidation-sensitization-activation approach. Activated carbon nanotubes catalyzed the metal deposition specifically onto their surfaces upon immersion in electroless plating baths. The method produced nanotubes decorated with silver. The extent of silver decoration was found to be dependent on fabrication conditions. Dense nano silver assembled on nanotube surfaces could be obtained by keeping a low reaction rate in the solution phase. The results here show that this method is an efficient and simple means of achieving carbon nanotubes being assembled by nano metal.展开更多
Drug-resistant bacteria present a severe threat to public health,emphasizing the importance of developing broad-spectrum antibacterial agents that are free from drug resistance.Among silver-based antibacterial agents,...Drug-resistant bacteria present a severe threat to public health,emphasizing the importance of developing broad-spectrum antibacterial agents that are free from drug resistance.Among silver-based antibacterial agents,nano-silver has been found to exhibit the most promising and comprehensive performance.The exploration of the antibacterial capacity and morphological changes of silver nanoparticles(AgNPs)could offer a starting point for the development of safe and efficient antibacterial agents.In this study,three types of nano-silver-modified polyphosphazene(PRV)nanoparticles with different morphologies were synthesized using precipitation polymerization.These nanoparticles were characterized using various techniques,including Fourier-transform infrared spectroscopy(FTIR),X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),and thermogravimetric analysis(TGA).The antibacterial activity of these nanoparticles against Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)was assessed using minimum inhibitory concentration(MiC)/minimum bactericidal concentration(MBC)tests and inverted fluorescence microscopy.Our results revealed that the antibacterial activity of silver nanoparticles can vary significantly depending on their immobilized form.Ag@PRV Strawberry-like nanoparticles(NPs)exhibited higher antibacterial activity compared to Ag@PRV Yolk-Shell NPs and Ag@PRV Cable-like nanofibers(NFs).Notably,all three types of synthesized nanoparticles demonstrated a stronger bactericidal effect on Gram-positive bacteria than Gram-negative bacteria.Live/dead bacterial staining and scanning electron microscopy demonstrated that silver can kill bacteria by altering the permeability of their cell membranes.These findings offer valuable insights for designing and practically applying new silver-based antibacterial agents in the future.展开更多
The possibility of printing conductive ink on textiles is progressively researched due to its potential benefits in manufacturing functional wearable electronics and improving wearing comfort.However,few studies have ...The possibility of printing conductive ink on textiles is progressively researched due to its potential benefits in manufacturing functional wearable electronics and improving wearing comfort.However,few studies have reported the effect of conductive ink formulation on electrodes directly screen-printed on flexible substrates,especially printing UV curable conductive ink on common textiles.In this work,a novel UV curable nano-silver ink with short-time curing and low temperature features was developed to manufacture the fully flexible and washable textile-based electrodes by screen printing.The aim of this study was to determine the influence of ink formulation on UV-curing speed,degree of conversion,morphology and electrical properties of printed electrodes.Besides,the application demonstration was highlighted.The curing speed and adhesion of ink was found depending dominantly on the type of prepolymer and the functionality of monomer,and the type of photoinitiator had a decisive effect on the curing speed,degree of double bond conversion and morphology of printed patterns.The nano-silver content is key to guarantee the suitable screen-printability of conductive ink and therefore the uniformity and high conductivity of textile-based electrodes.Optimally,an ink formulation with 60 wt%nano-silver meets the potential application requirements.The electrode with 1.0 mm width showed significantly high electrical conductivity of 2.47×10^(6)S/m,outstanding mechanical durability and satisfactory washability.The high-performance of electrodes screen-printed on different fabrics proved the feasibility and utility of UV curable nano-silver ink.In addition,the application potential of the conductive ink in fabricating electronic textiles(e-textiles)was confirmed by using the textile-based electrodes as the cathodes of silverzinc batteries.We anticipate the developed UV curable conductive ink for screen-printing on textiles can provide a novel design opportunity for flexible and wearable e-textile applications.展开更多
基金Project supported by the National Natural Science Foundation of China （Grant No.50277029） .
文摘Nano-Ag particles/polyacrylamide （PAM） composites were synthesized by γ irradiation method and then blended with ethylene vinyl acetate （EVA）. Dielectric behaviors of the Ag/PAM/EVA composites are investigated as a function of both the concentration and size of Ag particles. When concentration of the Ag fillers is rarely low, dielectric anomalies were first observed in contrast to the traditional percolation theory. As concentration of Ag increases, volume resistivity and breakdown field strength are enhanced, loss tangent （tan δ） reduced and dielectric constant kept invariable. In addition, the above variation became larger when the diameter of the Ag nano-particles is smaller. Such dielectric anomalies may be understood by considering the unique ＂Coulomb Blockade Effect＂ of the nano-sized Ag particles.
基金National Natural Science Foundation of China(Regional Fund)(No.51863020)
文摘Nano-silver and waterborne polyurethane(WPU)composite emulsion was synthesized.The average diameter of silver nanoparticles(SNPs)was about 20 nm,and the average diameter of WPU was 101.32 nm.The anti-bacteria finishing of a polypropylene non-woven fabric(NWF)was carried out by ultraviolet finishing technology and the double dipping twin-roll method.The standard AATCC100 was used to test the antimicrobial activity of the samples.The results showed that the antimicrobial rates of Klebsiella pneumoniae(K.pneumoniae)and Staphylococcus aureus(S.aureus)were above 90%,which indicated that the NWF finishing had good antimicrobial activity.In addition,the thermal stability,mechanical properties,whiteness and contact angle of antimicrobial finishing nonwovens were characterized.The results showed that the performance of antimicrobial nonwovens was stable at 300℃.The breaking strength was better than that of untreated nonwovens,and the contact angle reached 119.1°.
基金supported by the Major State Basic Research Development Program of China (No.10332020)
文摘A facile solution processed strategy of synthesizing nano silver assembled on carbon nanotubes （CNTs） at room temperature was put forward. Activated carbon nanotubes were used as precursors for preparing silver-decorated nanotubes. The nature of the decorated nanotubes was studied using transmission electron microscopy （TEM）, scanning electron microscopy （SEM）, and energy-dispersive X-ray spectroscopy （EDX）. The inert surfaces of carbon nanotubes were activated by introducing catalytic nuclei via an oxidation-sensitization-activation approach. Activated carbon nanotubes catalyzed the metal deposition specifically onto their surfaces upon immersion in electroless plating baths. The method produced nanotubes decorated with silver. The extent of silver decoration was found to be dependent on fabrication conditions. Dense nano silver assembled on nanotube surfaces could be obtained by keeping a low reaction rate in the solution phase. The results here show that this method is an efficient and simple means of achieving carbon nanotubes being assembled by nano metal.
基金financially supported by the Ningbo Scientific and Technological Innovation 2025 Major Project(No.2020Z097)Natural Science Foundation of Zhejiang Province(No.LY18E030009)+1 种基金Ningbo Clinical Research Center for Otolaryngology Head and Neck Disease(No.2022L005)Ningbo Medical and Health Brand Discipline(No.PPXK2018-02).
文摘Drug-resistant bacteria present a severe threat to public health,emphasizing the importance of developing broad-spectrum antibacterial agents that are free from drug resistance.Among silver-based antibacterial agents,nano-silver has been found to exhibit the most promising and comprehensive performance.The exploration of the antibacterial capacity and morphological changes of silver nanoparticles(AgNPs)could offer a starting point for the development of safe and efficient antibacterial agents.In this study,three types of nano-silver-modified polyphosphazene(PRV)nanoparticles with different morphologies were synthesized using precipitation polymerization.These nanoparticles were characterized using various techniques,including Fourier-transform infrared spectroscopy(FTIR),X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),and thermogravimetric analysis(TGA).The antibacterial activity of these nanoparticles against Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)was assessed using minimum inhibitory concentration(MiC)/minimum bactericidal concentration(MBC)tests and inverted fluorescence microscopy.Our results revealed that the antibacterial activity of silver nanoparticles can vary significantly depending on their immobilized form.Ag@PRV Strawberry-like nanoparticles(NPs)exhibited higher antibacterial activity compared to Ag@PRV Yolk-Shell NPs and Ag@PRV Cable-like nanofibers(NFs).Notably,all three types of synthesized nanoparticles demonstrated a stronger bactericidal effect on Gram-positive bacteria than Gram-negative bacteria.Live/dead bacterial staining and scanning electron microscopy demonstrated that silver can kill bacteria by altering the permeability of their cell membranes.These findings offer valuable insights for designing and practically applying new silver-based antibacterial agents in the future.
基金supported by the Fundamental Research Funds for the Central Universities(2232019G-01 and CUSFDH-D-2018026)the Shanghai Natural Science Foundation(20ZR1400500)。
文摘The possibility of printing conductive ink on textiles is progressively researched due to its potential benefits in manufacturing functional wearable electronics and improving wearing comfort.However,few studies have reported the effect of conductive ink formulation on electrodes directly screen-printed on flexible substrates,especially printing UV curable conductive ink on common textiles.In this work,a novel UV curable nano-silver ink with short-time curing and low temperature features was developed to manufacture the fully flexible and washable textile-based electrodes by screen printing.The aim of this study was to determine the influence of ink formulation on UV-curing speed,degree of conversion,morphology and electrical properties of printed electrodes.Besides,the application demonstration was highlighted.The curing speed and adhesion of ink was found depending dominantly on the type of prepolymer and the functionality of monomer,and the type of photoinitiator had a decisive effect on the curing speed,degree of double bond conversion and morphology of printed patterns.The nano-silver content is key to guarantee the suitable screen-printability of conductive ink and therefore the uniformity and high conductivity of textile-based electrodes.Optimally,an ink formulation with 60 wt%nano-silver meets the potential application requirements.The electrode with 1.0 mm width showed significantly high electrical conductivity of 2.47×10^(6)S/m,outstanding mechanical durability and satisfactory washability.The high-performance of electrodes screen-printed on different fabrics proved the feasibility and utility of UV curable nano-silver ink.In addition,the application potential of the conductive ink in fabricating electronic textiles(e-textiles)was confirmed by using the textile-based electrodes as the cathodes of silverzinc batteries.We anticipate the developed UV curable conductive ink for screen-printing on textiles can provide a novel design opportunity for flexible and wearable e-textile applications.
