The purpose of this study was to determine the size of zinc oxide nanoparticles (NPs-ZnO) synthesized by the chemical precipitation method from the precipitation reaction between zinc acetate and sodium hydroxide. Then, characterization was made by X-ray diffraction (XRD). The characterization results obtained by this instrumental method correspond to the zincite structure (ZnO) of the hexagonal system, whose crystalline structural data is registered in the ICDD file PDF 01-075-0576. The determination of the size of NPs-ZnO was performed using the Scherrer equation with data obtained from the diffraction data of the most important planes of the crystal structure of the synthesized nanoparticles. The size of the crystallites determined was approximately 21 nm. This method of determining the size of nanoparticles is not very exact, however, in laboratories that do not have electron microsc...

In this research, it was evaluated the size of industrial silicon dioxide nanoparticles (NPs- SiO2), and their influence on mechanical properties such as compression resistance in samples of type 1 Portland cement after their incorporation (4% by weight) in the formation of mortars, according to ASTM C 109. Through the characterization performed by DR-X technique, it was observed that NPs-SiO2 showed an approximate size of 12,1nm ± 0,3nm besides their amorphous nature. Using TEM analysis, measured sizes were between 10 to 20 nm, whereas the hydrodynamic size measured by DLS technique was 11,6nm ± 0,7nm. Because of the addition of 4% wt. of NPs-SiO2 in samples of type 1 Portland cement, an increase of compressive strength of 20,82 kgf/cm2 was obtained after 28 days, compared with samples of type 1 Portland cement without addition of silica nanoparticles. 

In the present work the simulation of the plasmonic behavior of gold nanospheres with diameters of 10, 20, 30, 40, 50 y 60 nm in aqueous medium against light with wavelenghts ranging from 400 to 650 nm was done. A greater contribution of the scattering to the extinction spectrum was observed as a function of the size of the nanosphere, which exhibited an exponential behavior.

The synthesis of the nanocomposite based on silver nanoparticles and O-carboxymethyl chitosan (NPsAg-CMQ), by the chemical reduction method, using the O-carboxymethylchitosan 0.01% and AgNO3 1 mM in a ratio of 3: 2, with a time of 30 minute reaction, at room temperature and neutral pH. The nanocomposite obtained from the complex [Ag(NH3)2]+ was synthesized under the same conditions as AgNO3 but at a basic pH. Using UV-VIS spectrophotometry, the plasmon formation of silver nanoparticles at 410nm was verified for both silver sources. The results by Dynamic Light Dispersion (DLS) for AgNO3, shows a monodisperse distribution of the nanocomposite with an average hydrodynamic size of 166.7 nm. In the case of the diamine silver [Ag(NH3)2] + 83.9% had an average size of 54.42 nm. and 15.2% of 4.48 nm. Infrared Spectroscopy Measurements with Fourier Transform (FT-IR) shows the inhibition of the s...

The waters of rivers, seas and lagoons contaminated by various sources, whether of natural or anthropogenic origin, contain polluting substances, among them they present a high bacterial load, which does not allow human consumption because it causes damage to human health. Therefore, the research carried out presents the study of the photocatalytic effect of zinc oxide nanoparticles (ZnONPS) as its mechanism of biochemical interaction with the consequent formation of reactive oxygen substances (ROS) and thus propose the interpretation of its subsequent Bactericidal effect by generating cellular damage in Staphylococcus aureus bacteria. According to the results obtained in an experimental pilot work, the decrease in colony formation evaluated through the plate culture method was reported, and it was determined that the concentration of 10- 4 g of ZnONPs/ mL of ZnO nanoparticles (synthesiz...