scholarly journals Antimicrobial nanospheres thin coatings prepared by advanced pulsed laser technique

2014 ◽  
Vol 5 ◽  
pp. 872-880 ◽  
Author(s):  
Alina Maria Holban ◽  
Valentina Grumezescu ◽  
Alexandru Mihai Grumezescu ◽  
Bogdan Ştefan Vasile ◽  
Roxana Truşcă ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Bacterial Infections ◽  
Pulsed Laser ◽  
Antimicrobial Effect ◽  
Average Diameter ◽  
Laser Evaporation ◽  
Laser Technique ◽  
Thin Coatings ◽  
Transmission Electron ◽  
Good Biocompatibility

We report on the fabrication of thin coatings based on polylactic acid-chitosan-magnetite-eugenol (PLA-CS-Fe3O4@EUG) nanospheres by matrix assisted pulsed laser evaporation (MAPLE). Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) investigation proved that the homogenous Fe3O4@EUG nanoparticles have an average diameter of about 7 nm, while the PLA-CS-Fe3O4@EUG nanospheres diameter sizes range between 20 and 80 nm. These MAPLE-deposited coatings acted as bioactive nanosystems and exhibited a great antimicrobial effect by impairing the adherence and biofilm formation of Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa) bacteria strains. Moreover, the obtained nano-coatings showed a good biocompatibility and facilitated the normal development of human endothelial cells. These nanosystems may be used as efficient alternatives in treating and preventing bacterial infections.

Effect of Laser Fluence on Siliver Nanoparticles Colloid

2011 ◽  
Vol 415-417 ◽  
pp. 747-750
Author(s):  
Bing Xu ◽  
Ren Guo Song ◽  
Chao Wang
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Laser Ablation ◽  
Laser Fluence ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Average Diameter ◽  
Distilled Water ◽  
Transmission Electron ◽  
Silver Target

In order to study the effects of laser fluence on silver nanoparticles colloid, the silver nanoparticles colloid was prepared by pulsed laser ablation of silver target for 10min in distilled water at different laser fluence. The particles size，morphologies and absorption spectroscopy of the obtained nanoparticles colloid were characterized by ultraviolet to visible (UV-Vis) spectrometer and transmission electron microscopy (TEM), the average diameter and its distribution were analyzed by Image-ProPlus software. The results shown that the average diameter of the silver nanoparticles prepared at the laser fluence of 4.2J/cm2 was the smallest (D=17.54nm), also, the distribution of particle size was narrowest (=36.86nm) and the morphologies were more homogeneous. It was confirmed that the nanoparticles size and shape could be controlled by pulsed laser ablation parameters.

Transmission electron microscopy characterization of the microstructure of Cd3As2 films prepared by pulsed-laser evaporation

1987 ◽  
Vol 65 (8) ◽  
pp. 961-965 ◽  
Author(s):  
G. J. C. Carpenter ◽  
J. J. Dubowski ◽  
D. F. Williams
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Pulsed Laser ◽  
The Body ◽  
Laser Evaporation ◽  
Transmission Electron ◽  
Transmission Electron Microscopy Characterization ◽  
Amorphous Substrates ◽  
Tetragonal Form ◽  
Microscopy Characterization

Transmission electron microscopy with an analytical X-ray system has been used to investigate Cd3As2 films prepared by pulsed-laser evaporation. The films were deposited on amorphous substrates at ~ 120 °C. They consisted mainly of a fine polycrystalline array. The crystal structure was identified as the body-centered tetragonal form of Cd3As2. No other crystallographic phase of Cd3As2 was observed. Some regions with amorphous or eutectic inclusions were also observed. These results have been correlated with the electrical properties of pulsed-laser evaporated Cd3As2 films.

Effect of Laser Repetition Rate on Silver Nanoparticles Colloid

2012 ◽  
Vol 538-541 ◽  
pp. 1888-1891 ◽  
Author(s):  
Bing Xu ◽  
Ren Guo Song ◽  
Chao Wang ◽  
Wang Zhao He
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Silver Nanoparticles ◽  
Repetition Rate ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Average Diameter ◽  
Distilled Water ◽  
Laser Repetition Rate ◽  
Transmission Electron

The silver nanoparticles colloid was prepared by pulsed laser ablation in distilled water under various laser repetition rates. The particles size, morphologies and absorption spectroscopy of the obtained nanoparticles colloids were characterized by ultraviolet to visible (UV-Vis) spectrometer and transmission electron microscopy (TEM). The average diameter and its distribution were analyzed by Image-ProPlus software. The results showed that the average diameter of the silver nanoparticles prepared at the laser repetition rate of 10 HZ was the smallest (D=29.75 nm), also, the distribution of particle size decreases with increasing the laser repetition rate.

Antifungal Effectiveness of Nanosilver Colloid against Rose Powdery Mildew in Greenhouses

2008 ◽  
Vol 135 ◽  
pp. 15-18 ◽  
Author(s):  
Hae Sic Kim ◽  
Hyun Suk Kang ◽  
Gyo Jin Chu ◽  
Hong Sik Byun
Keyword(s):  
Electron Microscopy ◽  
Powdery Mildew ◽  
Colloidal Solution ◽  
Physical Method ◽  
Average Diameter ◽  
Optical Microscope ◽  
Size Analysis ◽  
Large Area ◽  
Transmission Electron ◽  
Antifungal Effects

The antifungal effectiveness against rose powdery mildew using antimicrobial nanosilver colloidal solution was investigated. Double-capsulized nanosilver was prepared by chemical reaction of silver ion with aid of physical method, reducing agent and stabilizers. The average diameter of nanosilver was about 1.5 nm. They were highly stable and very well dispersive in aqueous solution. The Transmission electron microscopy and UV-vis spectrometer were used for measurements of size analysis and their stability, respectively. The nanosilver colloidal solution of concentration of 5000 ppm was diluted in 10 ppm of 500 kg and sprayed at large area of 3306 m2polluted by rose powdery mildew. The white rose powdery mildew fade out above 95 % after 2 days and was not recurred for a week. The antifungal effects were observed by an optical microscope and photographs.

Characterization of Al65.0Cu32.9Co2.1 Alloy Containing Nanofibres

2012 ◽  
Vol 186 ◽  
pp. 212-215
Author(s):  
Jacek Krawczyk ◽  
Włodzimierz Bogdanowicz ◽  
Grzegorz Dercz ◽  
Wojciech Gurdziel
Keyword(s):  
Electron Microscopy ◽  
Average Diameter ◽  
Chemical Compositions ◽  
X Ray ◽  
Transmission Electron ◽  
Orthogonal Set ◽  
T Phase ◽  
Terminal Area ◽  
Scanning Electron

Microstructure of terminal area of Al65Cu32.9Co2.1ingots (numbers indicate at.%), obtained via directional solidification was studied. Scanning Electron Microscopy, Transmission Electron Microscopy and X-ray powder diffraction were applied. Point microanalysis by Scanning Electron Microscope was used for examination of chemical compositions of alloy phases. It was found that tetragonal θ phase of Al2Cu stoichiometric formula was the dominate phase (matrix). Additionally the alloy contained orthogonal set of nanofibres of Al7Cu2Co T phase with the average diameter of 50-500 nm and oval areas of hexagonal Al3(Cu,Co)2H-phase, surrounded by monoclinic AlCu η1phase rim. Inside some areas of H-phase cores of decagonal quasicrystalline D phase were observed.

Laser assisted synthesis of WS2 nanorods by pulsed laser ablation in liquid environment

2021 ◽  
pp. 2140007
Author(s):  
Pankaj Koinkar ◽  
Kohei Sasaki ◽  
Tetsuro Katayama ◽  
Akihiro Furube ◽  
Satoshi Sugano
Keyword(s):  
Electron Microscopy ◽  
Laser Ablation ◽  
2D Materials ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Laser Ablation In Liquid ◽  
Simple Method ◽  
Liquid Environment ◽  
Transmission Electron ◽  
Specific Morphology

Two dimensional (2D) materials are widely attracting the interest of researchers due to their unique crystal structure and diverse properties. In the present work, tungsten disulfide (WS[Formula: see text] nanorods were synthesized by a simple method of pulsed laser ablation in liquid (PLAL) environment. The prepared WS2 are analyzed by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), UV-visible spectroscopy (UV-vis) and Raman spectroscopy to confirm the surface morphology, phase and structure. A possible growth mechanism of WS2 is proposed. This study indicates new door for the preparation of 2D materials with specific morphology.

Atomic Structure and Property Correlation in Pulsed Laser Deposited High -Tc Films

1998 ◽  
Vol 526 ◽  
Author(s):  
R. Kalyanaraman ◽  
S. Oktyabrsky ◽  
K. Jagannadham ◽  
J. Narayan
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Grain Boundaries ◽  
Atomic Structure ◽  
Substrate Surface ◽  
Pulsed Laser ◽  
Structure And Property ◽  
Transmission Electron ◽  
Tilt Boundaries ◽  
Z Contrast

AbstractThe atomic structure of grain boundaries in pulsed laser deposited YBCO/MgO thin films have been studied using transmission electron microscopy. The films have perfect texturing with YBCO(001)//MgO(001), giving rise to low-angle [001] tilt boundaries from the grains with the c-axis normal to substrate surface. Low angle grain boundaries have been found to be aligned preferentially along (100) and (110) interface planes. The energy of (110) boundary planes described by an alternating array of [100] and [010] dislocation is found to be comparable to the energy of a (100) boundary. The existence of these split dislocations is shown to further reduce the theoretical current densities of these boundaries indicating that (110) boundaries carry less current as compared to (100) boundaries of the same misorientation angle. Further, Z-contrast transmission electron microscopy of a 42° asymmetric high-angle grain boundary of YBCO shows evidence for the existence of boundary fragments and a reduced atomic density along the boundary plane

scholarly journals The formation of self-assembled structures of C60 in solution and in the volume of an evaporating drop of a colloidal solution

2020 ◽  
Vol 60 (3) ◽  
Author(s):  
Urol Kudratovich Makhmanov ◽  
Abdulmutallib Kokhkharov ◽  
Sagdilla Bakhramov ◽  
Donats Erts
Keyword(s):  
Electron Microscopy ◽  
Colloidal Solution ◽  
Substrate Surface ◽  
Flat Glass ◽  
Dissipative System ◽  
Average Diameter ◽  
Flat Substrate ◽  
Transmission Electron ◽  
Physical Features ◽  
Self Aggregation

The results of experiments on the self-aggregation of C60 fullerene molecules both inside a two-component solvent (xylene/tetrahydrofuran) and in the volume of an evaporating drop of C60 colloidal solution on a flat substrate surface are presented. The investigations of C60 solutions using dynamic light scattering, transmission electron microscopy and UV–Vis absorption spectroscopy methods revealed the possibility of synthesis of fractal nanoaggregates with a diameter of up to ~135 nm at low concentrations of C60 in the solutions. The final geometric dimensions of C60 nanoaggregates were determined by the initial concentration of fullerene in the solvent medium. Using the scanning electron microscopy method, we have shown that in an open dissipative system – in the volume of an evaporating droplet of the colloidal solution of fullerene C60 sessile on the surface of a flat glass substrate, large quasispherical nanoaggregates with an average diameter of ~380–800 nm are formed. The physical features and regularities that characterize the processes of self-aggregation of fullerene particles in the volume of a drying drop were determined.

Encapsulated Fullerenes Within Single Wall Carbon Nanotubes

1999 ◽  
Vol 5 (S2) ◽  
pp. 182-183
Author(s):  
Brian W. Smith ◽  
David E. Luzzi
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Pulsed Laser ◽  
Irradiation Damage ◽  
Laser Vaporization ◽  
Single Wall Carbon Nanotubes ◽  
Phase Object ◽  
Parallel Lines ◽  
Weak Phase ◽  
Transmission Electron

It is well documented that the pulsed laser vaporization of graphite produces both carbon nanotubes and C60 in the presence of certain metallic catalysts. In nanotube production most of the Ceo is removed along with other residual contaminants during succeeding purification and annealing steps. The possibility of C60 becoming trapped inside a nanotube during this elaborate sequence has been considered but not previously detected.Nanotubes are observed with high resolution transmission electron microscopy under conditions chosen to minimize both exposure time and irradiation damage. Since a nanotube satisfies the weak phase object approximation, its image is a projection of the specimen -potential in the direction of the electron beam. The image has maximum contrast where the beam encounters the most carbon atoms, which occurs where it is tangent to the tube’s walls. Thus, the image consists of two dark parallel lines whose separation is equal to the tube diameter, 1.4 nm.

Nanoindentation in Tin/Nbn Multilayers and Thin Films Examined Using Transmission Electron Microscopy

1999 ◽  
Vol 5 (S2) ◽  
pp. 776-777
Author(s):  
S.J. Lloyd ◽  
J.E. Pitchford ◽  
J.M. Molina-Aldareguia ◽  
Z.H. Barber ◽  
M.G. Blamire ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Deformation Structure ◽  
Tem Analysis ◽  
Repeat Distance ◽  
Cross Sectional ◽  
Thin Coatings ◽  
Transmission Electron ◽  
Salt Structure ◽  
Interesting System

Nanoindentation allows the hardness of thin coatings and synthetic multilayer structures to be measured, since indentation depths can be as little as a few 10s of nm. In combination with the cross-sectional transmission electron microscopy (TEM) analysis described here it is possible to observe the deformation structure under an indent, and potentially to understand deformation mechanisms on a nm scale in a wide variety of materials. Synthetic multilayers are a particularly interesting system to investigate. Variations in hardness with the multilayer compositional repeat distance (A) have been reported for several systems. The highest hardnesses, which are in excess of what a simple “rule of mixtures” would predict, occur in nitride multilayers at A ∼5nm. Here we present some preliminary results showing the deformation structure in both a monolithic NbN film and a TiN/NbN multilayer in which both components have the rQck salt structure with lattice parameters 0.424nm (TiN) and 0.439nm (NbN).

Sign in / Sign up

Export Citation Format

Share Document