scholarly journals The Effect of Ag Content of the Chitosan-Silver Nanoparticle Composite Material on the Structure and Antibacterial Activity

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Solmaz Akmaz ◽  
Esra Dilaver Adıgüzel ◽  
Muzaffer Yasar ◽  
Oray Erguven

The aim of this study is to investigate the antibacterial properties and characterization of chitosan-silver nanoparticle composite materials. Chitosan-silver nanoparticle composite material was synthesized by adding AgNO3and NaOH solutions to chitosan solution at 95°C. Different concentrations (0,02 M, 0,04 M, and 0,06 M) of AgNO3were used for synthesis. Chitosan-silver nanoparticle composite materials were characterized by Transmission electron microscopy (TEM), X-ray diffraction (XRD), ultraviolet (UV) spectrophotometer, and Fourier transform infrared (FTIR) spectrometer techniques.Escherichia coli,Acinetobacter baumannii,Staphylococcus aureus,Enterococcus faecalis,Pseudomonas aeruginosa, andStreptococcus pneumoniaewere used to test the bactericidal efficiency of synthesized chitosan-Ag nanoparticle composite materials. The biological activity was determined by the minimum bacterial concentration (MBC) of the materials. Antibacterial effect of chitosan-silver nanoparticle materials was increased by increasing Ag amount of the composite materials. The presence of small amount of metal nanoparticles in the composite was enough to significantly enhance antibacterial activity as compared with pure chitosan.

2021 ◽  
Vol 8 ◽  
Author(s):  
Qi Liu ◽  
Wen-Chong Ouyang ◽  
Xiu-Hong Zhou ◽  
Tao Jin ◽  
Zheng-Wei Wu

In this study, nanofibers with different ratios of poly(vinyl alcohol) and chitosan incorporated with moxifloxacin hydrochloride (MH/PVA/CS) were fabricated through the blending electrospinning, and the morphological features were tested using scanning electron microscopy (SEM). Further characterization of the new nanofiber was accomplished by Thermogravimetric analysis (TG), X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR). Antibacterial activity of the MH-loaded nanofibers at different drug loading were tested and compared with the blank group. Experimental results show that the MH/PVA/CS nanofibers exhibited the good antibacterial properties against Staphylococcus aureus and Pseudomonas aeruginosa due to the MH incorporation. Compared with blank nanofibers, MH/PVA/CS nanofibers have significantly better antibacterial properties, and different proportions of PVA and CS have a certain effect on the antibacterial activity of nanofibers. The conclusions in this paper show that MH/PVA/CS composite nanofibers may have great potential in antibacterial materials.


2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Monika Łukomska-Szymańska ◽  
Beata Zarzycka ◽  
Janina Grzegorczyk ◽  
Krzysztof Sokołowski ◽  
Konrad Półtorak ◽  
...  

The aim of the study was to evaluate antibacterial activity of composite materials modified with calcium fluoride against cariogenic bacteriaS. mutansandL. acidophilus. One commercially available conventional light-curing composite material containing fluoride ions (F2) and two commercially available flowable light-curing composite materials (Flow Art and X-Flow) modified with 1.5, 2.5, and 5.0 wt% anhydrous calcium fluoride addition were used in the study. Composite material samples were incubated in 0.95% NaCl at 35°C for 3 days; then dilution series ofS. mutansandL. acidophilusstrains were made from the eluates. Bacteria dilutions were cultivated on media afterwards. Colony-forming unit per 1 mL of solution (CFU/mL) was calculated. Composite materials modified with calcium fluoride highly reduced (p<0.001) bacteria growth compared to commercially available composite materials containing fluoride compounds. The greatest reduction in bacteria growth was observed for composite materials modified with 1.5% wt. CaF2. All three tested composite materials showed statistically greater antibacterial activity againstL. acidophilusthan againstS. mutans.


2006 ◽  
Vol 510-511 ◽  
pp. 78-81 ◽  
Author(s):  
Guo Yu Lv ◽  
Yu Bao Li ◽  
Ai Ping Yang ◽  
Xiang Zhang ◽  
Wei Hu Yang ◽  
...  

In this paper a series of silver ions-substituted hydroxyapatites (HA) were prepared. The antibacterial activities of these materials on textiles against bacteria have been investigated. Titania (TiO2) was selectively added into the materials to decrease the silver-ions concentration to get the same active antimicrobial effects. The microstructure, the shape and size, concentration of silver, and the groups of the composite materials were characterized using transmission electron microscopy (TEM), infrared spectroscopy (IR), Atomic absorption spectroscopy (AAS), and X-ray diffraction (XRD). The results showed that there was a dose dependent-effect of silver-ions concentration from the disk diffusion test. The higher the silver-ions concentration, the better the antibacterial activity of the composite materials was. Keeping silver-ions concentration constant, the antibacterial activity of the materials for adding Titania was better than that of without Titania. Moreover, the addition of Titania would inhibit the discolouration of the composite materials. The antibacterial activities of the composite materials differentiate to some extent with the bacterial strains.


2006 ◽  
Vol 920 ◽  
Author(s):  
Zhigang Hu ◽  
Jin Zhang ◽  
Wing Lai Chan ◽  
Yau Shan Szeto

AbstractNew stable silver oxide suspension in chitosan solution was prepared from a mixture of silver nitrate and chitosan in dilute acetic acid as precursor, in which the complex interactions between silver ion and chitosan was also investigated through various instrumentation method seriously. The suspension was charactized through laser scan, infrared ray spectroscopy (IR), ultraviolet-visible spectroscopy (UV-vis) and X-ray diffraction (XRD), which indicated that the interactions between silver and chitosan in its precursor were destroyed partially. The measurements of the nanoparticles through scanning electron microscopy (SEM) and transmission electron microscopy (TEM) disclosed the spherical profiles of these silver oxide nanoparticles of 10-20nm in average. Cotton fabrics treated by this emulsion were entitled remarkable antibacterial activity against S aureus and E. coli at pH 5 and 7 with sightless color effect and good washing fastness.


Author(s):  
R. E. Herfert

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.


Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4715
Author(s):  
Adam Kubiak ◽  
Marta Kubacka ◽  
Elżbieta Gabała ◽  
Anna Dobrowolska ◽  
Karol Synoradzki ◽  
...  

The TiO2-Fe3O4 composite materials were fabricated via the hydrothermal-assisted technique. It was determined how the molar ratio of TiO2 to Fe3O4 influences the crystalline structure and morphology of the synthesized composite materials. The effect of the molar ratio of components on the antibacterial activity was also analyzed. On the basis of XRD patterns for the obtained titanium(IV) oxide-iron(II, III) oxide composites, the two separate crystalline forms—anatase and magnetite —were observed. Transmission electron microscopy revealed particles of cubic and tetragonal shape for TiO2 and spherical for Fe3O4. The results of low-temperature nitrogen sorption analysis indicated that an increase in the iron(II, III) oxide content leads to a decrease in the BET surface area. Moreover, the superparamagnetic properties of titanium(IV) oxide-iron(II, III) oxide composites should be noted. An important aim of the work was to determine the antibacterial activity of selected TiO2-Fe3O4 materials. For this purpose, two representative strains of bacteria, the Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus, were used. The titanium(IV) oxide-iron(II, III) oxide composites demonstrated a large zone of growth inhibition for both Gram-positive and Gram-negative bacteria. Moreover, it was found that the analyzed materials can be reused as antibacterial agents in three consecutive cycles with good results.


Chemosensors ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 52
Author(s):  
Nermine V. Fares ◽  
Passant M. Medhat ◽  
Christine M. El Maraghy ◽  
Sherif Okeil ◽  
Miriam F. Ayad

Two inexpensive and simple methods for synthesis of carbon nanodots were applied and compared to each other, namely a hydrothermal and microwave-assisted method. The synthesized carbon nanodots were characterized using transmission electron microscopy (TEM), ultraviolet-visible (UV-Vis), photoluminescence (PL), Fourier transform-infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The synthesized microwave carbon nanodots had smaller particle size and were thus chosen for better electrochemical performance. Therefore, they were used for our modification process. The proposed electrodes performance characteristics were evaluated according to the IUPAC guidelines, showing linear response in the concentration range 10−6–10−2, 10−7–10−2, and 10−8–10−2 M of tobramycin with a Nernstian slope of 52.60, 58.34, and 57.32 mV/decade for the bare, silver nanoparticle and carbon nanodots modified carbon paste electrodes, respectively. This developed potentiometric method was used for quantification of tobramycin in its co-formulated dosage form and spiked human plasma with good recovery percentages and without interference of the co-formulated drug loteprednol etabonate and excipients.


1995 ◽  
Vol 418 ◽  
Author(s):  
J. Forbes ◽  
J. Davis ◽  
C. Wong

AbstractThe detonation of explosives typically creates 100's of kbar pressures and 1000's K temperatures. These pressures and temperatures last for only a fraction of a microsecond as the products expand. Nucleation and growth of crystalline materials can occur under these conditions. Recovery of these materials is difficult but can occur in some circumstances. This paper describes the detonation synthesis facility, recovery of nano-size diamond, and plans to synthesize other nano-size materials by modifying the chemical composition of explosive compounds. The characterization of nano-size diamonds by transmission electron microscopy and electron diffraction, X-ray diffraction and Raman spectroscopy will also be reported.


2012 ◽  
Vol 600 ◽  
pp. 174-177 ◽  
Author(s):  
Jian Fei Xia ◽  
Zong Hua Wang ◽  
Yan Zhi Xia ◽  
Fei Fei Zhang ◽  
Fu Qiang Zhu ◽  
...  

Zirconia-graphene composite (ZrO2-G) has been successfully synthesized via decomposition of ZrOCl2•6H2O in a water-isopropanol system with dispersed graphene oxide (GO) utilizing Na2S as a precursor could enable the occurrence of the deposition of Zr4+ and the deoxygenation of GO at the same time. Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) techniques were used to characterize the samples. It was found that graphene were fully coated with ZrO2, and the ZrO2 existing in tetragonal phase, which resulted in the formation of two-dimensional composite.


2012 ◽  
Vol 174-177 ◽  
pp. 508-511
Author(s):  
Lin Lin Yang ◽  
Yong Gang Wang ◽  
Yu Jiang Wang ◽  
Xiao Feng Wang

BiFeO3 polyhedrons had been successfully synthesized via a hydrothermal method. The as-prepared products were characterized by power X-ray diffraction (XRD) pattern, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The possible mechanisms for the formation of BiFeO3 polyhedrons were discussed. Though comparison experiments, it was found that the kind of precursor played a key role on the morphology control of BiFeO3 crystals.


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