Ag nanoparticle-embedded one-dimensional β-CD (β-cyclodextrin)/PVP composite nanofibers were prepared using a one-step electrospinning
technique. Ag nanoparticles were obtained in the AgNO3/β-CD/DMF solution, in which silver nitrate been introduced as the precursor, DMF as solvent, β-CD as reducing and capping
agent. After electrospinning of the composite solution at room temperature, the β-CD/PVP nanofibers containing Ag nanoparticles
were obtained. The electrospun composite solution containning Ag nsnopsrticles were confirmed by UV-visible absorption spectra;
the resulting composite nanofibers were characterized by scanning electron microscopy , transmission electron microscopy,
and X-ray diffraction. Ag-β-CD/PVP nanofiber exhibits good antibacterial property for Escherichia coli and Staphylococcus aureus. Consequently, we propose that these Ag nanoparticle-embedded 1D-nanostructures prepared via electrospinning may be used
as antibacterial material. 相似文献
Ag nanoparticles (Ag NPs) embedded titanium dioxide (TiO2) nanofibers were fabricated by colloidal sol process, electrospinning, and calcination technique. Calcination of the electrospun nanofibers were heat treated at 600°C for 180 minutes in air atmosphere. X-ray diffraction patterns exhibited that the anatase phase and silver coexisted in the resulted Ag NPs/TiO2 nanofibers; transmission electron microscopy demonstrated Ag NPs well spread in the porous microstructure of composite fibers. The prepared nanofibers were utilized as photocatalyst for degradation of methyl orange. The degradation rate of methyl orange dye solution containing Ag/TiO2 composite nanofibers is 99% only after irradiation for 3 hours. It is proposed that these new Ag NPs/TiO2 composite nanofibers will have potential application in water pollution treatment. 相似文献
A heat-treated PVA nanofibrous matrix containing silver (Ag) was prepared by electrospinning an aqueous 10 wt% PVA solution and followed by heat treatment at 150 °C for 10 min. The average diameter of the as-spun and heat-treated PVA nanofibers was 330 nm. The heat-treated PVA nanofibrous matrix containing Ag was irradiated with UV light to transform the Ag ions in the nanofibrous matrix into Ag nanoparticles. The in vitro cytotoxicity of the Ag ions and/or nanoparticles on normal human epidermal keratinocytes (NHEK) and fibroblasts (NHEF) cultures was examined. The PVA nanofibrous matrix containing Ag showed slightly higher level of attachment and spreading in the early stage culture (1 h) than the PVA nanofibers without Ag (control). However, compared with the PVA nanofibers without Ag, the heat-treated and UV-irradiated PVA nanofibers, containing mainly Ag ions and nanoparticles, respectively, showed reduced cell attachment and spreading. This shows that both Ag ions and Ag nanoparticles are cytotoxic to NHEK and NHEF. There was no significant difference in cytotoxicity to NHEK and NHEF between Ag ions and Ag nanoparticles. NHEF appeared to be more sensitive to Ag ions or particles than NHEK. In addition, the residual nitrate ions (NO3−) in the PVA nanofibers had an adverse effect on the culture of both cells. 相似文献
We report a new simple method to fabricate a highly active SERS substrate consisting of poly‐m‐phenylenediamine/polyacrylonitrile (PmPD/PAN) decorated with Ag nanoplates. The formation mechanism of Ag nanoplates is investigated. The synthetic process of the Ag nanoplate‐decorated PmPD/PAN (Ag nanoplates@PmPD/PAN) nanofiber mats consists of the assembly of Ag nanoparticles on the surface of PmPD/PAN nanofibers as crystal nuclei followed by in situ growth of Ag nanoparticles exclusively into nanoplates. Both the reducibility of the polymer and the concentration of AgNO3 are found to play important roles in the formation and the density of Ag nanoplates. The optimized Ag nanoplates@PmPD/PAN nanofiber mats exhibit excellent activity and reproducibility in surface‐enhanced Raman scattering (SERS) detection of 4‐mercaptobenzoic acid (4‐MBA) with a detection limit of 10?10 m , making the Ag nanoplates@PmPD/PAN nanofiber mats a promising substrate for SERS detection of chemical molecules. In addition, this work also provides a design and fabrication process for a 3D SERS substrate made of a reducible polymer with noble metals. 相似文献
Silver (Ag) nanoparticles were prepared in PAN nanofibrous film by a sol–gel derived electrospinning and subsequent chemical
reduction for 30 min in hydrazine hydroxide (N2H5OH) aqueous solution. Antimicrobial properties of the AgNO3/PAN precursor solution against gram positive Staphylococcus aureusATCC 6538 and gram negative Escherichia coli ATCC 25922 were investigated. The formation of clear zone suggested that the PAN solution containing Ag+ ions were effective on the inhibition of bacterial growth. The Ag/PAN nanocomposite film, characterized by XRD, TEM and UV
absorption spectrophotometer, revealed that highly crystallized cubic Ag particles with diameters of less than 5.8 nm were
dispersed homogeneously in PAN nanofibers. 相似文献
MOF-5 that sometimes called IRMOF-1 has been intensively studied in recent years to develop efficient photocatalyst to degrade refractory organics and inactivate bacteria for wastewater treatment. In the present work, Ag/Ag3PO4 nanoparticles incorporated in IRMOF-1 was successfully prepared via hydrothermal approach. The antibacterial activity of synthesized materials (IRMOF-1, Ag/Ag3PO4 nanoparticles and Ag/Ag3PO4-IRMOF-1 nanocomposite was compared against two types of bacteria (Escherichia coli (E. coil) as Gram negative and Staphylococcus aureus (S. aureus) as Gram-positive bacteria). The deactivation of the bacteria by the prepared material was measured in the dark and under visible light irradiation. The antibacterial activity of synthesized samples was investigated by determining the minimal inhibitory concentration (MIC), minimal bactericidal concentration (MBC), growth inhibition assay and inhibition zone. The Ag/Ag3PO4-IRMOF-1 nanocomposite exhibited stronger antibacterial activities than the Ag/Ag3PO4 nanoparticles and IRMOF-1 at all tested bacteria types. Based on inhibition zone, without any light irradiation, Ag/Ag3PO4-IRMOF-1 nanocomposite showed activity toward E. coil, but in presence of light nanocomposite depicted activity toward S. aureus. The results demonstrated that antibacterial activity of all synthesized samples in the dark and light against S. aureus bacteria was more than E. coil bacteria. The antibacterial activity mechanism was due to sustained-release of silver ions in the dark and reactive oxygen species (ROS) under visible light. The bioactivity of IRMOF-1 was related to the degradation of the its structure and the release of Zn2+ ions into the culture medium that bind to the cell wall and deactivation bacteria. 相似文献
Polyurethane foam is currently used as an exudate absorptive wound dressing material. In this study silver (Ag) nanoparticles were incorporated into electrospun polyurethane (PU) nanofiber to enhance the antibacterial as well as wound healing properties. The electrospinning parameters were optimized for PU with and without silver nanoparticles. Silver nanoparticles were synthesized by aqueous and organic methods. The water absorption, antibacterial and cytocompatibility of the PU-Ag nanofibers were studied and compared to that of conventional PU foam. The results indicated that the PU-Ag nanofibers could be used for wound dressing applications. 相似文献
An efficient, novel and convenient method for the synthesis of modified polyacrylonitrile (PAN) with antibacterial property is reported. The modification of PAN was prepared by a nitrile click chemistry reaction with sodium azide (NaN3) and silver nitrate (AgNO3) as catalyst to yield antibacterial polymeric materials with 5-vinyltetrazole units. The results showed that 5-vinyltetrazole units had coordinated with silver ion (Ag+). Through the electrostatic spinning technology, the post-modification PAN nanofibers (PAN–Ag+ nanofibers) were prepared and the fibers were tested for their antimicrobial properties by the bacterial infection experiment. Afterwards, the antibacterial and stable performance of different proportions of silver ions in PAN nanofibers has been compared. The PAN–Ag+ nanofibers are characterized for mechanical and thermomechanical properties, structural analysis, appearance characteristics, as well as the antibacterial properties. And the nanofibers exhibit marvelous chemical stability according to the thermogravimetric analysis. When at 800 °C, the PAN decomposed about 60%, while the decomposition of the PAN–Ag+s was 40%. Based on the bacterial infection experiment, PAN–Ag+ nanofibers’ antibacterial properties were stronger with the increase of silver ions, such as the number of bacteria clone was smaller and the bacteriostatic ring was larger. Hence, with combination of silver ions, the final polymers show strong antimicrobial properties. 相似文献
This paper describes the effect of embedding MgO and Al2O3 nanoparticles on the diameter of electrospun composite polyacrylonitrile (PAN) nanofibers. Diameter of nanofibers determines the important properties of the nanofibrous mats used in a variety of developed applications such as tissue engineering scaffolds, drug delivery, catalysis, ultra filtration, sensors, and nanoelectronics. The results showed that the type and amount of nanoparticles dispersed in PAN solutions affect the conductivity as well as the viscosity of the electrospinning solutions. Increasing the amount of MgO and Al2O3 leads to higher conductivity and higher viscosity of the electrospinning solution and ultimately to a smaller nanofiber diameter. Moreover, the results showed that higher conductivity of the electrospinning solution overcomes the effect of higher viscosity. Finally, no interaction was detected between metal oxide nanoparticles and PAN macromolecules. 相似文献
The highly porous Mn2O3‐Ag nanofibers were fabricated by a facile two‐step procedure (electrospinning and calcination). The structure and composition of the Mn2O3‐Ag nanofibers were characterized by SEM, TEM, XRD, EDX and SAED. The as‐prepared Mn2O3‐Ag nanofibers were then employed as the immobilization matrix for glucose oxidase (GOD) to construct an amperometric glucose biosensor. The biosensor shows fast response to glucose, high sensitivity (40.60 µA mM?1 cm?2), low detection limit (1.73 µM at S/N=3), low Km,app value and excellent selectivity. These results indicate that the novel Mn2O3‐Ag nanfibers‐GOD composite has great potential application in oxygen‐reduction based glucose biosensing. 相似文献
Biodegradable poly(l-lactide) (PLA) ultrafine fibers containing nanosilver particles were prepared via electrospinning. Morphology of the Ag/PLA fibers and distribution of the silver nanoparticles were characterized. The release of silver ions from the Ag/PLA fibers and their antibacterial activities were investigated. These fibers showed antibacterial activities (microorganism reduction) of 98.5% and 94.2% against Staphylococcus aureus and Escherichia coli, respectively, because of the presence of the silver nanoparticles. 相似文献
Interfacial polymerization technology was employed to immobilize silver (Ag) nanoparticles on the surface of commercial polyethersulfone (PES) membrane to develop antibacterial and antifouling ultrafiltration membrane. Ag nanoparticles were prepared from the reduction of silver nitrate (AgNO3) by sodium borohydride in the presence of polyethyleneimine (PEI) as the stabilizer. The encapsulated Ag nanoparticles in the PEI solution were embedded into the PEI membrane when trimesoyl chloride solution was used to crosslink the PEI solution with the PES membrane, forming Ag-polyamide (PA) networks through the interfacial polymerization reaction. Experimental results showed that the membrane prepared with 50 mmol/L of AgNO3 and 20 mmol/L of PEI had the optimized antibacterial effect against Escherichia coli. Bacterial concentration and species were also investigated. Exiguobacterium aestuarii and Staphylococcus aureus which are gram-positive bacteria, needed significantly more time for the Ag-PA/PES membrane to kill the bacteria completely when compared to E.coli and Vibrio coralliilyticus which are gram-negative bacteria. This study showed that Ag nanoparticles impregnated in membrane surfaces were 100% effective in killing various types of marine bacteria and bacteria in the seawater collected off Sentosa Island in Singapore. These membranes exhibit excellent antibacterial and antifouling properties which can be used to kill bacteria in ballast water and seawater. 相似文献
Bamboo charcoal supporting silver (BC/Ag) was prepared by activation and chemical reduction. The BC/Ag composites were characterized by silver particle size and distribution, silver ion (Ag+) release and antibacterial properties. Scanning and transmission electron microscopy (SEM and TEM) showed that the Ag particles were distributed uniformly on the BC matrix. The Ag particle size was found to be less than 150 nm based on TEM. The Ag+ release increased initially which was followed by a marginal increase between the 8th and 24th hour. Composites contained higher amounts of silver exhibited a further rise in Ag+ release from the 24‐hours of storage in water. The antibacterial effects of the BC/Ag composite powders against Pseudomonas aeruginosa and Staphylococcus aureus were assessed from the minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) method, and an excellent antibacterial performance was discovered. 相似文献
Two pure silver nanoparticles (Ag210(iPrPhS)71(Ph3P)5Cl and Ag211(iPrPhS)71(Ph3P)6Cl labeled as SD/Ag210 and SD/Ag211 (SD=SunDi), were found to co‐crystallize in forming compound 1 . Single‐crystal X‐ray diffraction (SCXRD) revealed that they differ by only one Ag(PPh3). Their four‐shell nanoparticles consist of three pure Ag metal shells (Ag19@Ag52@Ag45) shielded by a silver‐organic Ag89(iPrPhS)71Cl[Ag(Ph3P)]n outermost shell. The number (n) of Ag(Ph3P) is five for SD/Ag210 and six for SD/Ag211. The pseudo‐fivefold symmetric Ag nanoparticles exhibit surface plasmon absorption similar to a true metallic state but at the nanoscale. This work exemplifies the important effects of phosphine in stabilizing large silver nanoparticles; and offers a platform to investigate the origin of differences in nanoscale metal materials, even differing by only one metal atom; it also sheds light on the regioselective binding of auxiliary Ph3P on the surface of silver nanoparticles. 相似文献
Summary: Poly(N‐vinylpyrrolidone) (PVP) was used in two methods to prepare polymer nanofibers containing Ag nanoparticles. The first method involved electrospinning the PVP nanofibers containing Ag nanoparticles directly from the PVP solutions containing the Ag nanoparticles. N,N‐Dimethylformamide was used as a solvent for the PVP as well as a reducing agent for the Ag+ ions in the PVP solutions. In the second method, poly(vinyl alcohol) (PVA) aqueous solutions were electrospun with 5 wt.‐% of the PVP containing Ag nanoparticles. The Ag nanoparticles were evenly distributed in the PVA nanofibers. PVP containing Ag nanoparticles could be used to introduce Ag nanoparticles to other polymer nanofibers that are miscible with PVP.
TEM image of a PVA nanofiber electrospun with 5 wt.‐% of the PVP containing Ag nanoparticles. 相似文献