Investigation of the properties of PAN/f-MWCNTs/AgNPs composite nanofibers

2016 ◽  
Vol 47 (2) ◽  
pp. 149-172 ◽  
Author(s):  
Nuray Kizildag ◽  
Nuray Ucar
Keyword(s):  
Carbon Nanotubes ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Silver Nitrate ◽  
Composite Nanofibers ◽  
Chemical Reduction ◽  
Antimicrobial Properties ◽  
Reduction Process ◽  
Silver Ions ◽  
Mwcnt Content

In this study, composite nanofibers from a solution of polyacrylonitrile (PAN), functionalized multi-walled carbon nanotubes (f-MWCNTs), and silver nitrate (AgNO3) in dimethylsulfoxide were successfully produced by the electrospinning method. Aqueous solution of hydrazinium hydroxide was used for the chemical reduction of silver ions. The effects of the simultaneous use of carbon nanotubes (either pristine or amine-functionalized) and silver nitrate in different percentages and the application of chemical reduction on the properties of the nanocomposite nanowebs were investigated. FTIR, SEM, conductivity meter, tensile tester, XRD, and DSC were used for the characterization. Antibacterial activities of the nanocomposite nanowebs were determined against S. Aureus. Full factorial experimental design was utilized in order to be able to evaluate the contributions of the selected factors (f-MWCNT content, AgNO3 content, and application of reduction process) to the variations in ultimate tensile strength, elongation, and conductivity of the composite nanowebs. Analysis of variance (ANOVA) and multiple comparisons were carried out to evaluate the average nanofiber diameters and mechanical properties. PAN/f-MWCNTs/AgNPs nanowebs displayed enhanced conductivity and antimicrobial properties particularly when the chemical reduction process was applied. Besides they showed improved crystallinity compared with pure PAN nanofibers. While the reduction process made the highest contribution to the ultimate tensile strength, elongation, and conductivity of the nanowebs, f-MWCNT content had negligible effect on conductivity of the nanowebs. Considering all the results obtained in this study, composite nanofiber webs of PAN with 1 w% f-MWCNTs and 1 w%AgNO3 can be suggested for use as antistatic and antibacterial filaments.

Preparation and characterization of silver nanoparticle-porphyrazine composites

2013 ◽  
Vol 17 (10) ◽  
pp. 928-933
Author(s):  
Altuğ Mert Sevim ◽  
Ayşe Selda Keskin ◽  
Ahmet Gül
Keyword(s):  
Silver Nanoparticles ◽  
Chemical Reduction ◽  
Reduction Process ◽  
Silver Ions ◽  
Organic Medium ◽  
Nano Particles ◽  
Effective Manner ◽  
Vis Spectroscopy ◽  
One Step

A one step chemical reduction process was used for the preparation of hydrophilic silver nanoparticles ( AgNP ) using silver nitrate, sodiumborohydride and polyvinylpyrolidone as stabilizer. In the case of hydrophobic silver nanoparticles reduced silver ions were stabilized with cetyl trimethylammonium bromide (CTAB). The resultant nano particles were characterized by absoption spectra and their interactions with cationic cobalt (QCoPz) and neutral magnesium (MgPz) porphyrazines in water and in organic medium were investigated by using UV-vis spectroscopy and zeta potential techniques. It is confirmed that both metalloporphyrazine molecules interact with silver nanoparticles in an effective manner. The possible arrangement of the porphyrazines on the surfaces of the hydrophilic and hydrophobic AgNPs has been also discussed according to obtained spectroscopic results. These well-characterized novel AgNP -metalloporphyrazine composites are expected to be useful in optical and catalytic applications.

scholarly journals Characterization and Biocompatibility Properties of Silver Nanoparticles Produced Using Short Chain Polyethylene Glycol

2010 ◽  
Vol 10 ◽  
pp. 29-37 ◽  
Author(s):  
Maryam Jokar ◽  
Russly Abdul Rahman ◽  
Nor Azowa Ibrahim ◽  
Luqman Chuah Abdullah ◽  
Tan Chin Ping
Keyword(s):  
Silver Nanoparticles ◽  
Polyethylene Glycol ◽  
Chemical Reduction ◽  
Radical Scavenging ◽  
Agar Plate ◽  
Antimicrobial Properties ◽  
Silver Ions ◽  
Colloidal Dispersion ◽  
Short Chain ◽  
Uniform Size

Silver nanoparticles are of interest due to their unique physicochemical and antimicrobial properties. The nanoparticles were produced by chemical reduction using short chain polyethylene glycol (PEG) as reducing agent, solvent and stabilizer in absence of other chemicals. Silver nanoparticles were separated from colloidal dispersion by ultra centrifuge at 14000 rpm. The reduction of silver ion (Ag+) to silver nanoparticles (Agº) was monitored by pH measurement and UV-visible spectroscopy of colloidal dispersion at fixed intervals. Silver nanoparticles were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM) and diphenyl-picrylhydrazyl (DPPH) radical scavenging method. Antimicrobial activity of silver nanoparticles was investigated against Escherichia coli, Staphylococcus aureus and Vibrio parahaemolyticus by agar plate test. Results indicated 51.5% conversion efficiency of silver ions to silver nanoparticles. Colloidal dispersion containing 4.12 mg/ml silver nanoparticles showed uniform size of 5.5 ± 1.1 nm with a typical visible spectra band at 447 nm. Silver nanoparticles showed significant (p < 0.05) antimicrobial efficiency and with concentration of 100 ppm resulted in 46.22%, 66.51% and 69.06% inhibition against S. aureus, E. coli and V. parahaemolyticus, respectively. The nanoparticles were also found to reduce DPPH free radical up to 88.9%. Results of this study proved that the silver nanoparticles produced by polyethylene glycol possess antimicrobial and antioxidant activity.

Nanocomposite polyacrylonitrile filaments with electrostatic dissipative and antibacterial properties

2016 ◽  
Vol 50 (30) ◽  
pp. 4279-4289 ◽  
Author(s):  
Nuray Kizildag ◽  
Nuray Ucar
Keyword(s):  
Antibacterial Activity ◽  
Silver Nitrate ◽  
Chemical Reduction ◽  
Antibacterial Properties ◽  
Reduction Process ◽  
Nitrate Content ◽  
Visible Spectroscopy ◽  
Ion Release ◽  
Filament Structure ◽  
Silver Release

In this study, silver nitrate was added to polyacrylonitrile filament structure and chemical reduction was applied to composite filaments in order to develop multifunctional polyacrylonitrile filaments with electrostatic dissipative and antibacterial properties. Composite filaments of polyacrylonitrile and silver nitrate were characterized and evaluated in terms of morphology, chemical structure, tensile properties, crystallinity, conductivity, thermal properties, silver ion release behaviour and antibacterial activity. Additionally, ultraviolet-visible spectroscopy was used to confirm the formation of nanoparticles and the variation in the concentration of the nanoparticles with the application of the chemical reduction process. Scanning electron microscope images and ultraviolet-visible spectroscopy results confirmed the formation of nanoparticles in the filament structure. Breaking strength and breaking elongation increased at silver nitrate content of 1%. Composite filaments displayed improved thermal stability and their conductivities were in the semiconductive range. Atomic absorption spectroscopy confirmed that necessary amounts of silver release for antibacterial activity occurred, while the antibacterial activity analysis showed that the composite filaments have excellent antibacterial activity. The results obtained were promising and showed that the composite filaments could be used in electrostatic dissipative and antibacterial applications.

Photoconductivity for Silver Nitrate in Nanostructured Sol–Gel Materials

2008 ◽  
Vol 8 (12) ◽  
pp. 6569-6575
Author(s):  
Alfredo Franco ◽  
Víctor Rentería ◽  
Guadalupe Valverde-Aguilar ◽  
Jorge A. García-Macedo
Keyword(s):  
Optical Absorption ◽  
Silver Nitrate ◽  
Photovoltaic Effect ◽  
Sol Gel ◽  
Reduction Process ◽  
Silver Ions ◽  
Silver Colloids ◽  
Optical Absorption Band ◽  
Spontaneous Reduction ◽  
Silver Nitrate Concentration

We report on the photoconductive response of nanostructured sol–gel films in function of the silver nitrate concentration (ions and colloids). Silver colloids were obtained by spontaneous reduction process of Ag+ ions to Ag0. 2-d hexagonal nanosructured sol–gel thin films were prepared by dipcoating method using the non-ionic diblock copolymer Brij58 to produce channels into the film, which house the silver nanoparticles. An optical absorption band located at 430 nm was detected by optical absorption; it corresponds to the surface plasmon. A fit to this band with modified Gans theory is presented. Photoconductivity studies were performed on films with silver ions and films with silver colloids to characterize their mechanisms of charge transport in the darkness and under illumination at 420 and 633 nm wavelengths. The films with silver colloids exhibit a photovoltaic effect stronger than the films with silver ions. While a photoconductive behaviour is observed in the films with silver ions.

scholarly journals A fast and simple protocol for synthesizing effective antimicrobial silver nanoparticles in non-specialized facilities

2019 ◽  
Author(s):  
Roberto Vazquez-Munoz ◽  
M. Josefina Arellano-Jimenez ◽  
Jose L. Lopez-Ribot
Keyword(s):  
Silver Nanoparticles ◽  
Metallic Nanoparticles ◽  
Chemical Reduction ◽  
Nitrate Solution ◽  
Synthesis Method ◽  
Antimicrobial Properties ◽  
Reduction Process ◽  
Cost Effective ◽  
Silver Nitrate Solution ◽  
Average Size

Abstract Objective Silver nanoparticles (AgNPs) can be difficult or expensive to obtain or synthesize for laboratories in resource-limited facilities. The purpose of this work was to create a fast, facile, and cost-effective method for synthesizing AgNPs with potent antimicrobial properties, that can be readily implemented in non-specialized laboratories.Results Our developed method uses a rather simple and rapid chemical reduction process that involves the addition of a polyvinylpyrrolidone solution to a warmed silver nitrate solution under constant vigorous stirring, immediately followed by the addition of sodium borohydride with constant stirring for an additional 15 minutes. AgNPs had an aspect ratio close to 1, with an average size of 6.18 ± 5 nm. AgNPs displayed potent antimicrobial activity, with Minimal Inhibitory Concentration values of 3 µg mL-1 and 1.5 µg mL-1 for Staphylococcus aureus and Candida albicans respectively.Keywords : Silver nanoparticles, nanoantibiotics, synthesis method, AgNPs, metallic nanoparticles

Effect of silver nitrate on some mechanical properties of heat polymerizing acrylic resins

2019 ◽  
Vol 14 (1) ◽  
pp. 110
Author(s):  
Assiss. Prof. Dr. Sabiha Mahdi Mahdi ◽  
Dr. Firas Abd K. Abd K.
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Silver Nitrate ◽  
Surface Hardness ◽  
Mechanical Tests ◽  
Hardness Tester ◽  
Acrylic Resins ◽  
The Difference

Aim: The aimed study was to evaluate the influence of silver nitrate on surfacehardness and tensile strength of acrylic resins.Materials and methods: A total of 60 specimens were made from heat polymerizingresins. Two mechanical tests were utilized (surface hardness and tensile strength)and 4 experimental groups according to the concentration of silver nitrate used.The specimens without the use of silver nitrate were considered as control. Fortensile strength, all specimens were subjected to force till fracture. For surfacehardness, the specimens were tested via a durometer hardness tester. Allspecimens data were analyzed via ANOVA and Tukey tests.Results: The addition of silver nitrate to acrylic resins reduced significantly thetensile strength. Statistically, highly significant differences were found among allgroups (P≤0.001). Also, the difference between control and experimental groupswas highly significant (P≤0.001). For surface hardness, the silver nitrate improvedthe surface hardness of acrylics. Highly significant differences were statisticallyobserved between control and 900 ppm group (P≤0.001); and among all groups(P≤0.001)with exception that no significant differences between control and150ppm; and between 150ppm and 900ppm groups(P>0.05).Conclusion: The addition of silver nitrate to acrylics reduced significantly the tensilestrength and improved slightly the surface hardness.

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